Research Article Development of Educational Platform for ...
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Research ArticleDevelopment of Educational Platform forExperiments of Electric Machines
Yuan-Chieh Chin
Electrical Engineering Chienkuo Technology University Changhua 50094 Taiwan
Correspondence should be addressed to Yuan-Chieh Chin cycccctuedutw
Received 25 February 2014 Accepted 29 March 2014 Published 22 April 2014
Academic Editor Her-Terng Yau
Copyright copy 2014 Yuan-Chieh Chin This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
An educational platform to improve the test and the evaluation of the experimental data in electric machine laboratory isdevelopedThe system is complement to the course taught of electricmachines to undergraduate studentsThe proposed system canautomatically acquire the experimental data from data acquisition device on the personal computer and transfer the data throughinterface card to the host server The host sever performs the essential calculations of the obtained parameters After the studentsenter their computational value through system interface the host server could record compare estimate and chart the result inreal time The system not only improves the efficiency of the experimental data evaluation but also provides the online commentsincluding experimental purposes principles necessary instrument equipment special notes operation procedures and resultsrecording
1 Introduction
In 1988 Keyhani and Hao [1] proposed a microcomputer-aided data acquisition system for laboratory testing of trans-formers and electrical machines Their system focuses on themeasurement of the characteristics of synchronous machineand transformer The analysis software of Keyhani and Haorsquossystem only aims at the synchronous motor V type char-acteristic curve and transformers open-circuit short-circuitexperiments In 2000 Kasten [2] proposed an integratingcomputerized data acquisition and analysis system Kastenrsquossystem provides the safe operations of instrumentationsand measurement procedures over wide range of experi-mental tests The data acquisition and subsequent analysisof Knastanrsquos system is LabVIEW by National InstrumentsIn 2004 Sellschopp et al [3] proposed an automated sys-tem for frequency response analysis with application to anundergraduate laboratory of electrical machines Sellschoppand Arjonarsquos system provides a LabVIEW-based automatedsystem to carry out frequency response tests in electri-cal machines laboratory An advantage of Sellschopp andArjonarsquos system is its friendly-user interface and avoiding therisky utilization of oscilloscopes in laboratory experiment In
2006 Shuhui and Challoo [4] proposed a new approach thatby integrating computer-assisted teaching methodology inclassroom presentation substantially restructures the courseso that it provides a comprehensive treatment of electric-drive systems
In the traditional electric machinery experimental sys-tems of laboratory courses the students have always towait for a long time to get the instructorrsquos comments afterthey submit their experimental results Comparing withthe above mentioned systems propose an integrated onlinesystem with clientserver architecture to improve the recordevaluation and verification process of the experimental datain electric machine laboratory The proposed system canautomatically acquire the experimental data from data acqui-sition device on the personal computer and transfer the datathrough interface card to the host server The host sever per-forms the essential calculations of the obtained parametersAfter the students enter their computational value throughsystem interface the host server could record compareestimate and chart the result in real time The following liststhe seven achievements of the system and the eight functionsapplied in the electric machinery experiments
Hindawi Publishing CorporationMathematical Problems in EngineeringVolume 2014 Article ID 984638 10 pageshttpdxdoiorg1011552014984638
2 Mathematical Problems in Engineering
Figure 1 The practical instrument of one experimental set
The seven achievements are
(1) innovative and powerful database interconnectiontechnology with high feasibility
(2) practical data acquisition technology(3) highly portable recording technology(4) novel characteristic drawing technology without the
drawing orders(5) practical network database technology in production
office and study(6) innovative network data comparing and error auto-
matic distinguishing technology(7) smart technology to automatically adjust the param-
eters of the network practice
The eight functions of the online real-time electricmachineryexperimental system are
(1) automatic measurement computer-based data acqui-sition interface
(2) automatic recording it is convenient and portable forstudents to save the data
(3) characteristic curve drawing users can draw thecharacteristic figures by setting some variables
(4) online practice the network system can verify thecorrectness automatically
(5) online handover the network system can identify ifthe homework is handed
(6) online inquiring function for teachers teacherscan recognize students homework and examinationresults automatically
(7) online library it provides the online E-books forstudents to read and survey
(8) online smart questioning system it can adjust thedifficulty of the examination and grade automatically
In addition to the automatic measurement and recordingfunctions other education organizations without the auto-matic measuring interface can also use this system They canuse many functions such as automatic saving characteristiccurve drawing and online homework handover by import-ing the experimental data obtained with the traditionalwiring into this system
2 Laboratory Setup and System Architecture
The main equipment of laboratory includes the traditionalunits as follows transformers DC machines three-phasesynchronousmachines single phase inductionmotors three-phase induction motors and so forth Additional equipmentis por modules digit meters starters synchronous lampsload resistor banks and field rheostats In the proposed sys-tem wemust have the other equipment including voltage andcurrent transducers torque generator and speed generator tocombine with DAQ card and PC
The laboratory experiment may consist of many exper-imental sets The practical instrument of one experimentalset can be seen in Figure 1 Each set equips transformerinduction motor synchronous machine DC machine signalconditioner AD converter and PC with interface card Theoverall view of the system architecture is shown in Figure 2[5]
First the system must calculate the measurement datagrabbed at voltage signal and a current signal at an instantthrough the data acquisition card (PCL-818) [6] Then thevarious handwritten data can be record and save in Accessdatabase Make use of the concert of the database and ASP toupload to the host server systemThe host sever compares theautomated computational data with the upload data whichwas calculated by the studentThe verification results reply tothe client system immediately
In the laboratory experiments students have to assemblethe circuit connect the necessary instrument make themeasurements and essential computations compare the datato the expected behavior and input the computational datato PC The initial experimental signal should be processedthrough signals conditioner and DAQ card (PCL-818) sothat the converted experimental data can be transmitted topersonal computer and keep a record in client PC Afterthat students input their computational data and submitboth of the data including recorded measuring data indatabase and inputted computational data to host server viainterface cardThe integrated online system will compute therecorded measuring data automatically so that the systemcould compare the automated computational data to anotherdata which are inputted and computed by students lately
3 Parameters Determining
The equivalent circuits of electric machines are very usefultool for determining the electric machinesrsquo response to
Mathematical Problems in Engineering 3
Experiment set N
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
Experiment set 3Experiment set 2Experiment set 1
middot middot middot
middot middot middot
middot middot middot
middot middot middot
Signals conditionerSignals conditionerSignals conditionerSignals conditioner
AD converterand counter
AD converterand counter
AD converterand counter
AD converterand counter
PC 1 (client) PC 2 (client) PC 3 (client) PC N (client)
NET
Host PC (server)
Figure 2 The overall view of system architecture
changes in load However if a model is to be used for a realmachine it is necessary to what the elementary parametervalues are that go into the model How can the parametersbe determined for a real electric machine These pieces ofinformation may be found by performing a series of tests onthe electric machines
For example wanting to experimentally determine thevalues of the inductances and resistances in the transformermodel shown in Figure 3 an adequate approximation ofthese values can be obtained with only two tests the open-circuit test and the short-circuit test The open-circuit testconnections are shown in Figure 4 Full line voltage is appliedto the primary of the transformer and the input voltageinput current and input por to the transformer aremeasuredThe short-circuit test connections are shown in Figure 5The input voltage is adjusted until the current in the short-circuited windings is equal to its rated value
From this information the series equivalent elements119877eq119883eq and the admittance of the excitation branch 119877119862 119883119872 canbe determined as follows [7]
Themagnitude of the excitation admittance can be foundfrom the open-circuit test voltage and current
10038161003816100381610038161198841198641003816100381610038161003816 =119868OC119881OC (1)
The angle of the admittance can be found from knowledge ofthe circuit por factorThe open-circuit por factor (PF) is givenby
PF = cos 120579 =119875OC119881OC119868OC (2)
++
minusminus
IP
VP RC
jXeq
jXM
Req ISa
aVS
Figure 3 The approximation transformer model referred to theprimary side
Wattmeter
V
A
Transformer
+
minus
(t)
ip(t)
p(t)
Figure 4 Connection for transformer open-circuit test
and the por factor angle 120579 is given by
120579 = cosminus1119875OC119881OC119868OC (3)
4 Mathematical Problems in Engineering
Wattmeter
V
Transformer
A
(t)
ip(t)
+
minus
p(t)
is(t)
Figure 5 Connection for transformer short-circuit test
Transformer
DC generator
Inductionmachine
Main menu
Three-phaseinduction
Three-phaseinduction
motor generator
Single phaseinduction
motorSynchronous
motorSynchronous
generator DC motor
DC machineSynchronousmachine
Items selectionand test
Results analysisand upload
Ok
End
Yes
Host servercheck and record
Test again No
Figure 6 The overall view of the program modules and flow chart
Web serverServlet
JSPHTML
XML
Application server
JSP
HTML
XML Relational database
Client application
Firewall
Clientbrowser
Clientbrowser
Data-tierMiddle-tierClient-tier
(Inside)
(Outside)
Figure 7 Multitier architecture
Mathematical Problems in Engineering 5
Signals conditioner
Voltage signals
Network interface card N
Host PC (server)
Torque signal
Speed signal
Current signals
CN1 CN2
PCL-818
Figure 8 The processing flow of the experimental signals
+
+
+
_
V+
V+
Vminus
Vminus
V+
Vminus
Signal in
Signal in
Signal out
minus
minus
C1 C2 C3
R1 R2
R3 R4
C4 C5 C6
C7
C8
R5
R6
C9
C10
C11
C12
R7
R8
R10
R9
C13
C14
Figure 9 One channel voltage signal conditioner
Therefore the admittance 119884119864is
119884119864=119868OC119881OCang minus 120579 =
119868OC119881OCang minus cosminus1PF = 119866
119862minus 119895119861119872
=1
119877119862
minus 1198951
119883119872
(4)
and themagnitude of the series impedance can be found fromthe short-circuit test voltage and current
1003816100381610038161003816119885SE1003816100381610038161003816 =119881SC119868SC (5)
The por factor of current is given by
PF = cos 120579 =119875SC119881SC119868SC (6)
and the overall impedance angle 120579 is given by
120579 = cosminus1119875SC119881SC119868SC (7)
Therefore the series impedance 119885SE is equal to
119885SE =119881SC119868SCang120579 =119881SC119868SCang minus cosminus1PF = 119877eq + 119895119883eq (8)
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
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2 Mathematical Problems in Engineering
Figure 1 The practical instrument of one experimental set
The seven achievements are
(1) innovative and powerful database interconnectiontechnology with high feasibility
(2) practical data acquisition technology(3) highly portable recording technology(4) novel characteristic drawing technology without the
drawing orders(5) practical network database technology in production
office and study(6) innovative network data comparing and error auto-
matic distinguishing technology(7) smart technology to automatically adjust the param-
eters of the network practice
The eight functions of the online real-time electricmachineryexperimental system are
(1) automatic measurement computer-based data acqui-sition interface
(2) automatic recording it is convenient and portable forstudents to save the data
(3) characteristic curve drawing users can draw thecharacteristic figures by setting some variables
(4) online practice the network system can verify thecorrectness automatically
(5) online handover the network system can identify ifthe homework is handed
(6) online inquiring function for teachers teacherscan recognize students homework and examinationresults automatically
(7) online library it provides the online E-books forstudents to read and survey
(8) online smart questioning system it can adjust thedifficulty of the examination and grade automatically
In addition to the automatic measurement and recordingfunctions other education organizations without the auto-matic measuring interface can also use this system They canuse many functions such as automatic saving characteristiccurve drawing and online homework handover by import-ing the experimental data obtained with the traditionalwiring into this system
2 Laboratory Setup and System Architecture
The main equipment of laboratory includes the traditionalunits as follows transformers DC machines three-phasesynchronousmachines single phase inductionmotors three-phase induction motors and so forth Additional equipmentis por modules digit meters starters synchronous lampsload resistor banks and field rheostats In the proposed sys-tem wemust have the other equipment including voltage andcurrent transducers torque generator and speed generator tocombine with DAQ card and PC
The laboratory experiment may consist of many exper-imental sets The practical instrument of one experimentalset can be seen in Figure 1 Each set equips transformerinduction motor synchronous machine DC machine signalconditioner AD converter and PC with interface card Theoverall view of the system architecture is shown in Figure 2[5]
First the system must calculate the measurement datagrabbed at voltage signal and a current signal at an instantthrough the data acquisition card (PCL-818) [6] Then thevarious handwritten data can be record and save in Accessdatabase Make use of the concert of the database and ASP toupload to the host server systemThe host sever compares theautomated computational data with the upload data whichwas calculated by the studentThe verification results reply tothe client system immediately
In the laboratory experiments students have to assemblethe circuit connect the necessary instrument make themeasurements and essential computations compare the datato the expected behavior and input the computational datato PC The initial experimental signal should be processedthrough signals conditioner and DAQ card (PCL-818) sothat the converted experimental data can be transmitted topersonal computer and keep a record in client PC Afterthat students input their computational data and submitboth of the data including recorded measuring data indatabase and inputted computational data to host server viainterface cardThe integrated online system will compute therecorded measuring data automatically so that the systemcould compare the automated computational data to anotherdata which are inputted and computed by students lately
3 Parameters Determining
The equivalent circuits of electric machines are very usefultool for determining the electric machinesrsquo response to
Mathematical Problems in Engineering 3
Experiment set N
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
Experiment set 3Experiment set 2Experiment set 1
middot middot middot
middot middot middot
middot middot middot
middot middot middot
Signals conditionerSignals conditionerSignals conditionerSignals conditioner
AD converterand counter
AD converterand counter
AD converterand counter
AD converterand counter
PC 1 (client) PC 2 (client) PC 3 (client) PC N (client)
NET
Host PC (server)
Figure 2 The overall view of system architecture
changes in load However if a model is to be used for a realmachine it is necessary to what the elementary parametervalues are that go into the model How can the parametersbe determined for a real electric machine These pieces ofinformation may be found by performing a series of tests onthe electric machines
For example wanting to experimentally determine thevalues of the inductances and resistances in the transformermodel shown in Figure 3 an adequate approximation ofthese values can be obtained with only two tests the open-circuit test and the short-circuit test The open-circuit testconnections are shown in Figure 4 Full line voltage is appliedto the primary of the transformer and the input voltageinput current and input por to the transformer aremeasuredThe short-circuit test connections are shown in Figure 5The input voltage is adjusted until the current in the short-circuited windings is equal to its rated value
From this information the series equivalent elements119877eq119883eq and the admittance of the excitation branch 119877119862 119883119872 canbe determined as follows [7]
Themagnitude of the excitation admittance can be foundfrom the open-circuit test voltage and current
10038161003816100381610038161198841198641003816100381610038161003816 =119868OC119881OC (1)
The angle of the admittance can be found from knowledge ofthe circuit por factorThe open-circuit por factor (PF) is givenby
PF = cos 120579 =119875OC119881OC119868OC (2)
++
minusminus
IP
VP RC
jXeq
jXM
Req ISa
aVS
Figure 3 The approximation transformer model referred to theprimary side
Wattmeter
V
A
Transformer
+
minus
(t)
ip(t)
p(t)
Figure 4 Connection for transformer open-circuit test
and the por factor angle 120579 is given by
120579 = cosminus1119875OC119881OC119868OC (3)
4 Mathematical Problems in Engineering
Wattmeter
V
Transformer
A
(t)
ip(t)
+
minus
p(t)
is(t)
Figure 5 Connection for transformer short-circuit test
Transformer
DC generator
Inductionmachine
Main menu
Three-phaseinduction
Three-phaseinduction
motor generator
Single phaseinduction
motorSynchronous
motorSynchronous
generator DC motor
DC machineSynchronousmachine
Items selectionand test
Results analysisand upload
Ok
End
Yes
Host servercheck and record
Test again No
Figure 6 The overall view of the program modules and flow chart
Web serverServlet
JSPHTML
XML
Application server
JSP
HTML
XML Relational database
Client application
Firewall
Clientbrowser
Clientbrowser
Data-tierMiddle-tierClient-tier
(Inside)
(Outside)
Figure 7 Multitier architecture
Mathematical Problems in Engineering 5
Signals conditioner
Voltage signals
Network interface card N
Host PC (server)
Torque signal
Speed signal
Current signals
CN1 CN2
PCL-818
Figure 8 The processing flow of the experimental signals
+
+
+
_
V+
V+
Vminus
Vminus
V+
Vminus
Signal in
Signal in
Signal out
minus
minus
C1 C2 C3
R1 R2
R3 R4
C4 C5 C6
C7
C8
R5
R6
C9
C10
C11
C12
R7
R8
R10
R9
C13
C14
Figure 9 One channel voltage signal conditioner
Therefore the admittance 119884119864is
119884119864=119868OC119881OCang minus 120579 =
119868OC119881OCang minus cosminus1PF = 119866
119862minus 119895119861119872
=1
119877119862
minus 1198951
119883119872
(4)
and themagnitude of the series impedance can be found fromthe short-circuit test voltage and current
1003816100381610038161003816119885SE1003816100381610038161003816 =119881SC119868SC (5)
The por factor of current is given by
PF = cos 120579 =119875SC119881SC119868SC (6)
and the overall impedance angle 120579 is given by
120579 = cosminus1119875SC119881SC119868SC (7)
Therefore the series impedance 119885SE is equal to
119885SE =119881SC119868SCang120579 =119881SC119868SCang minus cosminus1PF = 119877eq + 119895119883eq (8)
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Mathematical Problems in Engineering 3
Experiment set N
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
TransformerInduction machines
Synchronous machinesDC machines
Experiment set 3Experiment set 2Experiment set 1
middot middot middot
middot middot middot
middot middot middot
middot middot middot
Signals conditionerSignals conditionerSignals conditionerSignals conditioner
AD converterand counter
AD converterand counter
AD converterand counter
AD converterand counter
PC 1 (client) PC 2 (client) PC 3 (client) PC N (client)
NET
Host PC (server)
Figure 2 The overall view of system architecture
changes in load However if a model is to be used for a realmachine it is necessary to what the elementary parametervalues are that go into the model How can the parametersbe determined for a real electric machine These pieces ofinformation may be found by performing a series of tests onthe electric machines
For example wanting to experimentally determine thevalues of the inductances and resistances in the transformermodel shown in Figure 3 an adequate approximation ofthese values can be obtained with only two tests the open-circuit test and the short-circuit test The open-circuit testconnections are shown in Figure 4 Full line voltage is appliedto the primary of the transformer and the input voltageinput current and input por to the transformer aremeasuredThe short-circuit test connections are shown in Figure 5The input voltage is adjusted until the current in the short-circuited windings is equal to its rated value
From this information the series equivalent elements119877eq119883eq and the admittance of the excitation branch 119877119862 119883119872 canbe determined as follows [7]
Themagnitude of the excitation admittance can be foundfrom the open-circuit test voltage and current
10038161003816100381610038161198841198641003816100381610038161003816 =119868OC119881OC (1)
The angle of the admittance can be found from knowledge ofthe circuit por factorThe open-circuit por factor (PF) is givenby
PF = cos 120579 =119875OC119881OC119868OC (2)
++
minusminus
IP
VP RC
jXeq
jXM
Req ISa
aVS
Figure 3 The approximation transformer model referred to theprimary side
Wattmeter
V
A
Transformer
+
minus
(t)
ip(t)
p(t)
Figure 4 Connection for transformer open-circuit test
and the por factor angle 120579 is given by
120579 = cosminus1119875OC119881OC119868OC (3)
4 Mathematical Problems in Engineering
Wattmeter
V
Transformer
A
(t)
ip(t)
+
minus
p(t)
is(t)
Figure 5 Connection for transformer short-circuit test
Transformer
DC generator
Inductionmachine
Main menu
Three-phaseinduction
Three-phaseinduction
motor generator
Single phaseinduction
motorSynchronous
motorSynchronous
generator DC motor
DC machineSynchronousmachine
Items selectionand test
Results analysisand upload
Ok
End
Yes
Host servercheck and record
Test again No
Figure 6 The overall view of the program modules and flow chart
Web serverServlet
JSPHTML
XML
Application server
JSP
HTML
XML Relational database
Client application
Firewall
Clientbrowser
Clientbrowser
Data-tierMiddle-tierClient-tier
(Inside)
(Outside)
Figure 7 Multitier architecture
Mathematical Problems in Engineering 5
Signals conditioner
Voltage signals
Network interface card N
Host PC (server)
Torque signal
Speed signal
Current signals
CN1 CN2
PCL-818
Figure 8 The processing flow of the experimental signals
+
+
+
_
V+
V+
Vminus
Vminus
V+
Vminus
Signal in
Signal in
Signal out
minus
minus
C1 C2 C3
R1 R2
R3 R4
C4 C5 C6
C7
C8
R5
R6
C9
C10
C11
C12
R7
R8
R10
R9
C13
C14
Figure 9 One channel voltage signal conditioner
Therefore the admittance 119884119864is
119884119864=119868OC119881OCang minus 120579 =
119868OC119881OCang minus cosminus1PF = 119866
119862minus 119895119861119872
=1
119877119862
minus 1198951
119883119872
(4)
and themagnitude of the series impedance can be found fromthe short-circuit test voltage and current
1003816100381610038161003816119885SE1003816100381610038161003816 =119881SC119868SC (5)
The por factor of current is given by
PF = cos 120579 =119875SC119881SC119868SC (6)
and the overall impedance angle 120579 is given by
120579 = cosminus1119875SC119881SC119868SC (7)
Therefore the series impedance 119885SE is equal to
119885SE =119881SC119868SCang120579 =119881SC119868SCang minus cosminus1PF = 119877eq + 119895119883eq (8)
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
4 Mathematical Problems in Engineering
Wattmeter
V
Transformer
A
(t)
ip(t)
+
minus
p(t)
is(t)
Figure 5 Connection for transformer short-circuit test
Transformer
DC generator
Inductionmachine
Main menu
Three-phaseinduction
Three-phaseinduction
motor generator
Single phaseinduction
motorSynchronous
motorSynchronous
generator DC motor
DC machineSynchronousmachine
Items selectionand test
Results analysisand upload
Ok
End
Yes
Host servercheck and record
Test again No
Figure 6 The overall view of the program modules and flow chart
Web serverServlet
JSPHTML
XML
Application server
JSP
HTML
XML Relational database
Client application
Firewall
Clientbrowser
Clientbrowser
Data-tierMiddle-tierClient-tier
(Inside)
(Outside)
Figure 7 Multitier architecture
Mathematical Problems in Engineering 5
Signals conditioner
Voltage signals
Network interface card N
Host PC (server)
Torque signal
Speed signal
Current signals
CN1 CN2
PCL-818
Figure 8 The processing flow of the experimental signals
+
+
+
_
V+
V+
Vminus
Vminus
V+
Vminus
Signal in
Signal in
Signal out
minus
minus
C1 C2 C3
R1 R2
R3 R4
C4 C5 C6
C7
C8
R5
R6
C9
C10
C11
C12
R7
R8
R10
R9
C13
C14
Figure 9 One channel voltage signal conditioner
Therefore the admittance 119884119864is
119884119864=119868OC119881OCang minus 120579 =
119868OC119881OCang minus cosminus1PF = 119866
119862minus 119895119861119872
=1
119877119862
minus 1198951
119883119872
(4)
and themagnitude of the series impedance can be found fromthe short-circuit test voltage and current
1003816100381610038161003816119885SE1003816100381610038161003816 =119881SC119868SC (5)
The por factor of current is given by
PF = cos 120579 =119875SC119881SC119868SC (6)
and the overall impedance angle 120579 is given by
120579 = cosminus1119875SC119881SC119868SC (7)
Therefore the series impedance 119885SE is equal to
119885SE =119881SC119868SCang120579 =119881SC119868SCang minus cosminus1PF = 119877eq + 119895119883eq (8)
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Mathematical Problems in Engineering 5
Signals conditioner
Voltage signals
Network interface card N
Host PC (server)
Torque signal
Speed signal
Current signals
CN1 CN2
PCL-818
Figure 8 The processing flow of the experimental signals
+
+
+
_
V+
V+
Vminus
Vminus
V+
Vminus
Signal in
Signal in
Signal out
minus
minus
C1 C2 C3
R1 R2
R3 R4
C4 C5 C6
C7
C8
R5
R6
C9
C10
C11
C12
R7
R8
R10
R9
C13
C14
Figure 9 One channel voltage signal conditioner
Therefore the admittance 119884119864is
119884119864=119868OC119881OCang minus 120579 =
119868OC119881OCang minus cosminus1PF = 119866
119862minus 119895119861119872
=1
119877119862
minus 1198951
119883119872
(4)
and themagnitude of the series impedance can be found fromthe short-circuit test voltage and current
1003816100381610038161003816119885SE1003816100381610038161003816 =119881SC119868SC (5)
The por factor of current is given by
PF = cos 120579 =119875SC119881SC119868SC (6)
and the overall impedance angle 120579 is given by
120579 = cosminus1119875SC119881SC119868SC (7)
Therefore the series impedance 119885SE is equal to
119885SE =119881SC119868SCang120579 =119881SC119868SCang minus cosminus1PF = 119877eq + 119895119883eq (8)
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
6 Mathematical Problems in Engineering
+
Signal in
Signal inSignal out
Hall-sensor
R1
minus
V+
Vminus
C1
C2
VR1
VR2
VR3
Figure 10 One channel current signal conditioner
ConditionerSpeed signal
Clock out
(a)
ConditionerTorque signal
Voltage out
(b)
Figure 11 Speed signal conditioner and torque signal conditioner
+
minus DIF
CHA
CHB
500 V
100 V
10 V
+
minus DIF
500 V
100 V
10 V
10 V
25 V
10 V
25 V
A
B
Figure 12 Voltage converter
100 kΩ times 1
100 120583F times2
N4001 times 4
Figure 13 Rectifier
The above-mentioned items the input voltage inputcurrent and input por to the transformer can be measuredmanually by students and automatically by the system If themeasurement is performed in the automatic mode all thepor signals would be handled based on the rules of signalprocessing in the following where 119868 is the effective value ofline current 119881 is the effective value of line voltage 119878
119894is the
input apparent por 119876119894is the input reactive por and 119875
119894is the
input active por [8ndash10]
119868 = radic(1
119899)
119899
sum
119894=1
(119868119894)2
119881 = radic(1
119899)
119899
sum
119894=1
(119881119894)2
119878119894= radic3119881119868
119876119894= radic31
119899
119899
sum
119894=1
(119881119894) (119868119894)
119875119894= radic(119878
119894)2minus (119876119894)2
(9)
From the above equations the required quantities can beobtained through the calculation program designed withvisual basic with the extracted voltage and current signalsfrom data acquisition card
4 System Interface and Soft Architecture
The system interface was designed on the basis of convenientuse and friendly interaction between student and this systemThe overall view of the program module and flow chartis shown in Figure 6 By using the system interface it isvery convenient to choose different kinds of experimentalmachine and the subunitsrsquo experiment can be proceededsubsequently The system program can be divided into twoparts client system and host server systemThe client systemis written in visual basic and MS access and runs on top of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Mathematical Problems in Engineering 7
Addressdecoder
Status
Data buffer
DMA logic
IRQ logic
Register
Select
PC b
us
Data mux
12 bit ADconverter
Sampleand hold
Gainswitch
Prog GainAmplifier
ChannelScan Logic
Logic
RAM
Trig
16 bitDig out
16 bitDig in
MUX16 SE
or8 DIFF
Counter number 1
Counter number 2
Counter number 0
2 CH 12 bitcode latch
2 CH 12 bitcode latch
LCLREMcontrol
10 MHZOSC
10
10
100 MHz
1 MHz
10 MHzIn
InOut
Out
Internal data bus
CTR0 CLKCTR0 gate
CLK1
CLK2
Out1
Out2
DA 0
DA 1
CTR0 out8254
EOC
Digitaloutput
Digitalinput
Analoginput
Figure 14 DAQ card (PCL-818)
Figure 15 The title screen
Windows XP Professional or Windows 7 Professional Thehost server system is writing in HTML and active server page(ASP) and runs on top ofWindows 7 Server Both of the clientand server computers have to connect to LAN or internet
In this paper the development environment includes VBand internet-based programs Therefore the whole structureof software can also be divided intoVB and internet operationmodes
The internet-based program is mainly focused on thedesign and arrangement of online operation where the func-tions of plot of characteristic curve development of online
Figure 16 The pop-up menu appears
platform for automatic data evaluation online examinationfunction for teachers and online database are included
N-tier application architecture provides amodel bywhichdevelopers can create flexible and reusable applications Bysegregating an application into tiers require the option ofmodifying or adding a specific layer instead of reworkingthe entire application A three-tier architecture is typicallycomposed of a presentation tier a business or data accesstier and a data tier The current internet is mainly the b-based structure which is three-tie architecture followed bythe collected mainframe and two-tier clientserver In theb development field three-tier architecture is often used to
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
8 Mathematical Problems in Engineering
Figure 17 The subunit three-phase induction motor load test
refer to websites commonly electronic commerce websiteswhich are built using three tiers
(1) A front end b server serving static content andpotentially some cached dynamic content In b-basedapplication front end is the content rendered bythe browser The content may be static or generateddynamically
(2) Amiddle dynamic content processing and generationlevel application server for example Ruby on RailsJava EE ASPNET PHP ColdFusion and Perl plat-form
(3) A back-end database or data store comprising bothdata sets and the database management system soft-ware that manages and provides access to the data
In the three-tie architecture the connection and coor-dination between servers would be more complicated thanthose in two-tie structure when dealing with a service Forthe users in the client the distributed processing can beconveniently completed with single internet connection andthe uniform user interface of browser Figure 7 is the typicalthree-tie application structure developed with JAVA [11 12]
The three-tie structure includes client-tie for user inter-face middle-tie for core application tools and data-tie fordata storage and processing The middle-tie can be furtherdivided into b-tie and application-tie The application-tieis composed of Enterprise Java Beans (EJB) to deal withimplementation of specific task The user can be the oneaccessed from internet or EJB And the b server is thegateway to access the system for user through the internetThis structure not only provides the distributed applicationenvironment but also completes the cross-platform functionThe firewall performs the encryption and verification
Therefore the teaching and experiment system in thispaper is designed with Java Server Pages (JSP) which is a newdynamic webpage standard introduced by SunMicrosystemsin June 1999 JSP is a b development technology based on JavaServlet and Java groups which is an extension of Servlet 21
APIWith this advanced technology the dynamicwebsite canbe built with security and cross-platform functions
The structure of JSP is similar to ASP However ASPis only applied in Windows NT2000 On the other handJSP can be directly applied in most b servers without anymodification to meet the idea of Java - ldquowrite once runanywhererdquo
Java2 platform enterprise edition is a structure for enter-prise applications developed by Sun This structure has beensupported by many software providers and has becomethe main product of enterprise application JSP is a keycomponent on the platform of J2EE JSP and ASP bothare based on the Web development technology for dynamicweb pages These two techniques can also provide softwarecompiled function for designers and make the webpageseparated logically In addition they both can provide moreconvenient and simpler development of website than CGI
5 Experimental Results
The processing flow of the experimental signals is shown inFigure 8 The details of transducers in the signal block aredescribed in Figures 9 10 11 12 and 13 The DAQ card isshown in Figure 14
When the student starts the client system heshe canchoose English or Chinese interface and the title screen isshown as in Figure 15 After the title screen the pop-upmenuwill appear as shown in Figure 16 The student can chooseexperimental unit and subunit according to hisher experi-mental purpose in Figure 16 For example a student chosethe induction motor unit then heshe could get the subunitthree-phase induction motor load test as shown in Figure 17The screen in Figure 17 can be divided into three windowsThe left window expresses the content of the experimentincluding purpose principle instrument equipment specialnote operation procedure and result recording The rightupper window shows the automated measured experimentaldata The right bottom window shows the wiring diagramof the chosen experiment After the students select (click)the test button in Figure 17 the measurement model will begotten as shown in Figures 18 and 19
Another case is the three-phase synchronous motor v-curve test shown in Figures 16 and 21 They show nonload12 full load and full load V-curves and inverse V-curves ofthe three-phase synchronous motor
As can be seen in Figures 18 19 20 and 21 the smallerleft-up window of the screen shows the automated measuredexperimental data The left-down window shows the curvesaccording to what has been chosen which was describedin the right bottom window (the differences between themas shown in Figure 18 to Figure 21) In the meantime theexperimental data is resaved as an access table which includesthe calculated value by student The access file can beuploaded to the host server system through the b-basedinterface as shown in Figure 22
The host sever compares the automated computationaldata with the upload data which was calculated by thestudent The verification results reply to the client system
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Mathematical Problems in Engineering 9
Figure 18 The measurement model 1 (speed versus current porfactor torque etc)
Figure 19 The measurement model 2 (por versus efficiency)
Figure 20 The V-curves (load current versus field current on thesame graph to the same scale)
Figure 21 The inverse V-curves (por factor versus field current onthe same graph to the same scale)
Figure 22 The b-base upload interface
Figure 23 The experimental check screen
immediately The b screen showed the comparisons betweenthe automated computation data and the calculated dataFigure 23 showed the experimental check screen
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
10 Mathematical Problems in Engineering
6 Conclusions
An educational platform for undergraduate student in elec-tric machines is developed in this paper The goal of theproject is to provide a real-time system which possessesautomatic data acquisition measurement analysis and real-time verification and instructional comment for experimentto electricmachines laboratoryThe advantages of this systemmake the student more familiar with theory and practice inspecific content of electrical machines course Besides theinstructor could efficiently and rapidly evaluate the studentrsquosexperimental results and reply to the comment immediately
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
References
[1] A Keyhani and S Hao ldquoMicrocomputer-aided data acquisitionsystem for laboratory testing of transformers and electricalmachinesrdquo IEEE Transactions on Power Systems vol 3 no 3pp 1328ndash1334 1988
[2] D G Kasten ldquoIntegrating computerized data acquisition andanalysis into an undergraduate electric machines laboratoryrdquoin Proceedings of the 30th ASEEIEEE Frontiers in EducationConference pp 13ndash17 Kansas City Mo USA 2000
[3] F S Sellschopp A Marco and L Arjona ldquoAn automatedsystem for frequency response analysis with application toan undergraduate laboratory of electrical machinesrdquo IEEETransactions on Education vol 47 no 1 pp 57ndash64 2004
[4] L Shuhui and R Challoo ldquoRestructuring an electric machinerycourse with an integrative approach and computer-assistedteaching methodologyrdquo IEEE Transactions on Education vol49 no 1 pp 16ndash28 2006
[5] Y C Chin ldquoThe computer-aided system for electric machinerylabrdquo in Proceedings of the UICEE Annual Conference on Engi-neering Education pp 183ndash185 Queensland Australia 2003
[6] Advantech Data Acquisition Card (PCL-818) Advantech Co2007
[7] S J Chapman Electric Machinery Fundamental McGraw-Hill5nd edition 2010
[8] ldquoIEEE standard definitions for the measurement of electricpower quantities under sinusoidal nonsinusoidal balanced orunbalanced conditionsrdquo IEEE Std 1459-2010 IEEE Standard2010
[9] ldquoElectromagnetic Compatibility (EMC)mdashPart 4-30 Testingand Measurement TechniquesmdashPower Quality MeasurementMethodsrdquo IEC Std 61000-4-30 2008
[10] MH J Bollen and I YHGu Signal Processing of PowerQualityDisturbances John Wiley amp Sons 2006
[11] F Martin Patterns of Enterprise Application Architecture Addi-son-Wesley 2002
[12] W W Eckerson ldquoThree Tier clientserver architecture achiev-ing scalability performance and efficiency in client server app-licationsrdquo Open Information Systems vol 10 no 1 1995
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of