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D5.4 HANDBOOK OF INNOVATIVE TECHNOLOGIES

TO PROMOTE SHP

WORK PACKAGE 5 - COMMON STRATEGIES TOIMPROVE SHP IMPLEMENTATION

Final Version 1Date 25.08.2011

R. Magureanu (POLI-B), S. Ambrosi (POLI-B), B. Popa (POLI-B),Bostan Ion (MOLD), Dulgheru Valeriu (MOLD), Bostan Viorel (MOLD),

Sochirean Anatol (MOLD)



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INDEX

PREFACE ............................................................................................................................................. 5

1. LIST OF ABBREVIATIONS .............................................................................................................. 6

2. INTRODUCTION .............................................................................................................................. 7

3. SMART MEASUREMENTS FOR SMALL HYDROPOWER PLANTS (RO) ................................... 8

4. INNOVATIVE TECHNOLOGIES TO PRODUCE SHP (MOLD) ..................................................... 24

4.1. IDENTIFICATION AND EVALUATION OF POTENTIAL SITES FOR SHP IMPLEMENTATION (ON RIVER PRUT) .. 24

5. ELABORATION OF INNOVATIVE TECHNOLOGIES TO PRODUCE SHP .................................. 31

5.1. ELABORATION OF FLOATING MICRO HYDROPOWER PLANTS FOR RIVER WATER KINETIC ENERGY

CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY ....................................................................... 31

5.1.1. Conceptual diagrams ................................................................................................................ 31

5.1.2. Micro hydro power plant for river water kinetic energy conversion into electrical Micro hydro power plant (figure 26) [9] ................................................................................................................... 33

5.1.3. Design of the hydrodynamic rotor ............................................................................................. 38 5.2. INDUSTRIAL PROTOTYPES OF MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR .................... 58

5.2.1. Pilot station of micro hydropower plant with hydrodynamic rotor for river water kinetic energyconversion into mechanical energy (MHCF D4x1,5 M) ...................................................................... 58 5.2.2. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion intoelectrical and mechanical energy (MHCF D4x1,5ME) ........................................................................ 62 5.2.3. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into

electrical and mechanical energy at small speeds (MHCF D4x1,5ME) ............................................. 65

5.2.4. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion intoelectrical energy (MHCF D4x1,5E) ..................................................................................................... 67

6. SUMMARY AND CONCLUSIONS ................................................................................................. 70

ANNEX ............................................................................................................................................... 71

7. REFERENCES ............................................................................................................................... 75

Figure index

FIGURE 1 - M AP OF ROMANIA WITH MAIN RIVERS, MAJOR, MEDIUM AND SMALL HYDRO PLANTS ..................... 8

FIGURE 2 - RIVER ARGES WITH MAJOR AND SMALL HYDRO PLANTS ............................................................. 8

FIGURE 3 - H/Q AND Η/Q CHARACTERISTICS FOR SMALL HYDRO TURBINES ................................................. 9

FIGURE 4 - MIHAILESTI SMALL HYDRO PLANT WITH ONE FRANCIS AND TWO K APLAN TURBINES ..................... 9

FIGURE 5 - MEASUREMENT DIAGRAM FOR MIHAILESTI SHP ..................................................................... 10

FIGURE 6 - ARBITER SYSTEMS – POWER SENTINEL PHASOR MEASUREMENT UNIT ................................... 10

FIGURE 7 – WIDE AREA MONITORING SYSTEM (WAMS) .......................................................................... 11

FIGURE 8 - D ATA COLLECTED FROM PHASOR MEASUREMENT UNIT 1 AT MIHAILESTI SHP; A) VOLTAGES, B) CURRENTS, C) RMS D ATA, D) PHASORS ......................................................................................... 12

FIGURE 9 - THE PMUS IN ELPROS NETWORK AND REPRESENTATION OF VOLTAGES, PHASORS, FREQUENCY

IN ALL FOUR ACQUISITION POINTS .................................................................................................... 13

FIGURE 10 - D ATA COLLECTED FROM MIHAILESTI PMU ON THE OUTPUT 20KV OUTPUT LINE ...................... 14

FIGURE 11 - N ATIONAL INSTRUMENTS COMPACT RIO PROGRAMMABLE AUTOMATION CONTROLLER .......... 15

FIGURE 12 – POWER MONITORING APPLICATION SCREENSHOTS ............................................................. 18

FIGURE 13 - DIAGRAM FOR THE DIFFERENTIAL PROTECTION USING A COMPACT RIO EQUIPMENT .............. 19

FIGURE 14 - ZIGBEE NETWORK ............................................................................................................. 20

FIGURE 15 - SEA ZIGBEE MODULE ........................................................................................................ 20



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FIGURE 16 - DIGI XBEE MODULE .......................................................................................................... 20

FIGURE 17 - D ATA MONITORING APPLICATION .......................................................................................... 21

FIGURE 18 - C ARLO G AVAZZI ENERGY M ANAGEMENT SMART POWER QUALITY TRANSDUCER ................... 22

FIGURE 19 – SCREENSHOTS OF SCADA POWER MONITORING APPLICATION ........................................... 23

FIGURE 20 – M AP OF ENERGETIC POTENTIAL ON PRUT: ........................................................................... 24

FIGURE 21 – FP 201 GLOBAL W ATER FLOW PROBE. .............................................................................. 25

FIGURE 22 – ALIMENTATION SCHEME FOR PRUT RIVER FROM RIGHT AND LEFT BANKS WITH TRIBUTARIES

WATERS. ........................................................................................................................................ 26

FIGURE 23 – MEASUREMENTS OF THE FLOW SPEED ON PRUT RIVER. ....................................................... 28

FIGURE 24 – CONCEPTUAL DIAGRAM OF THE WATER WHEEL WITH RECTILINEAR PROFILE OF BLADES. ......... 32

FIGURE 25– CONCEPTUAL DIAGRAM OF THE WATER ROTOR WITH HYDRODYNAMIC PROFILE OF BLADES WITH

ITS ORIENTATION TOWARDS THE WATER STREAMS. ........................................................................... 32

FIGURE 26 – FLOATABLE MICRO HYDROPOWER PLANT WITH BLADES ORIENTATION MECHANISM. ................. 34

FIGURE 27– POSITIONING OF BLADES TOWARDS THE WATER CURRENTS. .................................................. 34

FIGURE 28 – FLOATING MICRO HYDROPOWER PLANT WITH ELECTRIC GENERATOR AND HYDRAULIC PUMP. .. 35

FIGURE 29 – FLOATING MICRO HYDROPOWER PLANT WITH INFLUENCE COMPENSATION OF WATER CURRENTS

FLOW DIRECTION CHANGE. .............................................................................................................. 36

FIGURE 30 – MICRO HYDROPOWER PLANT WITH INCREASED TRANSVERSE STABILITY. ................................ 37

FIGURE 31 – FLUID CYCLIC MOTION AROUND PROFILE .C ....................................................................... 41

FIGURE 32 – DIGITIZATION OF PROFILE .C ............................................................................................. 41

FIGURE 33 – BOUNDARY ELEMENT . j E .................................................................................................. 42

FIGURE 34 – SYMMETRIC HYDRODYNAMIC PROFILES: NACA 0012, 0016, 63018 AND 67015. ................. 45

FIGURE 35 – HYDRODYNAMIC LIFT LC AND DRAG

DC COEFFICIENTS DEPENDANT ON THE ENTERING ANGLE

FOR NACA 0012, 0016, 63018 AND 67015 PROFILES. ................................................................... 46

FIGURE 36 - HYDRODYNAMIC LIFT LC AND DRAG

DC COEFFICIENTS DEPENDANT ON THE ENTERING ANGLE

FOR NACA 0016 PROFILE. ........................................................................................................... 47

FIGURE

37 –

B

LADE POSITION AND WORKING AREAS. .............................................................................. 47

FIGURE 38– MODULE, TANGENTIAL COMPONENT AND NORMAL COMPONENT OF THE HYDRODYNAMIC FORCE

OF A ROTOR BLADE DEPENDING ON THE ANGLE OF POSITIONING. ....................................................... 47

FIGURE 39 – MOMENT,r i

T DEVELOPED BY THE ROTOR BLADE DEPENDING ON THE ANGLE OF POSITIONING. 48

FIGURE 40 – TOTAL MOMENTr T DEVELOPED BY 5 BLADES AT ROTOR SHAFT DEPENDING ON THE ANGLE OF

POSITIONING. ................................................................................................................................. 48

FIGURE 41 – TOTAL MOMENTr

T AT ROTOR SHAFT DEPENDING ON THE ANGLE OF POSITIONING FOR VARIOUS

VELOCITIES OF THE WATER FLOW .................................................................................................... 48

FIGURE 42 – NUMBER OF TURNS, M ref C DEPENDING ON THE ENTERING ANGLE FOR NACA 0016 PROFILE 48

FIGURE 43 – LOCATION OF THE BLADE FIXING POINT. ............................................................................... 49

FIGURE 44 – MOMENT DEVELOPED BY THE BLADE,r i

T DEPENDING ON THE POSITIONING ANGLE FOR VARIOUS

VALUES OF THE ENTERING ANGLE 15 , 17 , 18 , 20 .o o o o

.............................................................. 49

FIGURE 45 – TOTAL MOMENTr

T DEPENDING ON THE POSITIONING ANGLE FOR VARIOUS VALUES OF THE

ENTERING ANGLE 15 , 17 , 18 , 20 .o o o o ..................................................................................... 49

FIGURE 46 – TOTAL MOMENTr T DEVELOPED AT THE 3-, 4- AND 5-BLADE ROTOR SHAFT DEPENDING ON THE

POSITIONING ANGLE. ...................................................................................................................... 50

FIGURE 47 – NACA 0016 HYDRODYNAMIC RACK PROFILE STANDARD. ..................................................... 51

FIGURE 48 – NACA 0016 HYDRODYNAMIC RACK PROFILE STANDARD AND THE OPTIMISED PROFILE. .......... 51

FIGURE 49 – BLADES PROTOTYPING 5- AXIS MACHINE .............................................................................. 51

FIGURE 50 – FLOATING STABILITY ANALYSIS. ........................................................................................... 52

FIGURE 51 – MIGRATION TRAJECTORY OF THE CENTRAL POINT OF APPLICATION OF THE ARCHIMEDES FORCES

FOR THE 3-BLADE ( A) AND 5-BLADE ROTOR (B). ................................................................................ 53

FIGURE 52 – DEPENDENCE OF DISTANCE E OF THE CENTRAL POINT OF APPLICATION OF THE ARCHIMEDES

FORCES ON THE POSITIONING ANGLE OF THE 3-BLADE ROTOR ( A) AND OF 5-BLADE ROTOR (B). ...... 54



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FIGURE 53 – VELOCITY FIELD AROUND NACA 0016 PROFILE AT THE ENTERING ANGLE18o. ...................... 54

FIGURE 54 – POINT OF SEPARATION FOR THE FLOW VELOCITIES 1 M/S ( A) AND 2 M/S (B). ........................... 55

FIGURE 55 – 3-BLADE HYDRODYNAMIC ROTOR. ....................................................................................... 55 FIGURE 56 – 5-BLADE HYDRODYNAMIC ROTOR. ....................................................................................... 55

FIGURE 57 – MULTIBLADE ROTOR CONNECTED KINEMATICALLY TO THE ELECTRIC (GENERATOR 1) ENERGY OR

MECHANICAL HYDRAULIC PUMP 2) ENERGY PRODUCTION UNITS......................................................... 56

FIGURE 58 – ROTORS WITH 3- ( A) AND 5-BLADES (B) WITH HYDRODYNAMIC PROFILE, MANUFACTURED IN THE

LABORATORY OF THE CENTRE FOR RENEWABLE ENERGY CONVERSION SYSTEMS DESIGN, TUM. ..... 56

FIGURE 59 – GENERATED POWER AT ROTOR SHAFT. ................................................................................ 58

FIGURE 60 – MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER KINETIC ENERGY

CONVERSION INTO MECHANICAL ENERGY FOR WATER PUMPING (FLOW RATE Q = 40M3/H, PUMPING

HEIGHT H =10...15 M) .................................................................................................................... 59

FIGURE 61 – KINEMATICS OF MICRO HYDROPOWER PLANT MHCF D4X1,5 M. .......................................... 60

FIGURE 62 – TORQUE T 1 AT THE HYDRODYNAMIC ROTOR SHAFT WITH NACA 0016 PROFILE BLADES. ....... 60

FIGURE 63 – INDUSTRIAL PROTOTYPE OF THE MICROHYDROPOWER STATION FOR THE RIVER KINETIC ENERGY

CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGIES (DIAMETER OF ROTOR D = 4M , SUBMERSEDHEIGHT OF THE BLADE H = 1,4M , LENGTH OF BLADE L =1,3M ) (MHCF D4X1,5 ME). .......................... 62


CONVERSION INTO MECHANICAL ENERGY INSTALLED ON THE RIVER PRUT, V. STOIENEŞTI, C ANTEMIR. . 62


CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY (ROTOR DIAMETER D = 4 M , SUBMERGED

HEIGHT OF BLADE H = 1,4 M , LENGTH OF BLADE CHORD L = 1,3 M ) (MHCF D4X1,5 ME) .................... 64

FIGURE 66 – KINEMATICS OF MICRO HYDROPOWER PLANT MHCF D4X1,5 ME. ........................................ 65


CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY USED FOR WATER PUMPING (ROTOR DIAMETER

D = 4 M , SUBMERGED HEIGHT OF BLADE H = 1,4 M , LENGTH OF BLADE CHORD L = 1,3 M ). .................. 66

FIGURE 68 – UNIT OF THREE-STAGE HYDRAULIC PUMP DRIVING MECHANISM PSS 40-10/50. ..................... 67

FIGURE 69 – UNIT OF LOW SPEED ELECTRIC GENERATOR DRIVING MECHANISM (MCHF D4X1,5E). ........... 67

FIGURE 70 – MICRO HYDRO POWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER WATER KINETIC ENERGYCONVERSION INTO ELECTRICAL ENERGY (5-BLADE ROTOR DIAMETER D = 4 M , SUBMERGED HEIGHT OF

BLADE H = 1,4 M , LENGTH OF BLADE CHORD L = 1,3 M ). .................................................................... 68


CONVERSION INTO ELECTRICAL ENERGY (DIAMETER OF ROTOR D = 4M , SUBMERSED HEIGHT OF THE

BLADE H = 1,4M , LENGTH OF BLADE L =1,3M ) (MHCF D4X1,5 E) ..................................................... 69

FIGURE 71 – TORQUE T1 AT THE SHAFT OF 5-BLADE HYDRODYNAMIC ROTOR WITH NACA 0016 PROFILE .. 69

FIGURE 73 – FREE FLOW TURBINE, VERDANT POPWER ........................................................................... 71

FIGURE 74 – FREE FLOW TURBINE, UEK CORPORATION UNDERWATER ELECTRIC KITE ............................ 72

FIGURE 75 – FREE FLOW TURBINE, SWAN TURBINE ................................................................................. 73

FIGURE 76 – FREE FLOW TURBINE, GORLOV HELICAL TURBINE ................................................................ 74

FIGURE 77 – FREE FLOW TURBINE, MILLAU VLH ..................................................................................... 74

Table index

T ABLE 1 – W ATER FLOW VELOCITY ON PRUT RIVER IN DIFFERENT AREAS. ................................................. 30



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PrefaceThe present work is an outcome of the project “SEE HYDROPOWER, targeted to improve waterresource management for a growing renewable energy production” , in the frame of the South-East-Europe Transnational Cooperation Programme, co-funded by the European Regional DevelopmentFund (www.seehydropower.eu).

The project is based on the European Directive on the promotion of Electricity from RenewableEnergy Sources respect to the Kyoto protocol targets, that aims to establish an overall bindingtarget of 20% share of renewable energy sources in energy consumption to be achieved by eachMember State, as well as binding national targets by 2020 in line with the overall EU target of 20%.Objectives of the SEE HYDROPOWER deal with the promotion of hydro energy production in SEEcountries, by the optimization of water resource exploitation, in a compatible way with other waterusers following environmental friendly approaches. Therefore, it gives a strong contribution to the

integration between the Water Frame and the RES-e Directives.

Main activities of the project concerns the definition of policies, methodologies and tools for abetter water & hydropower planning and management; the establishment of common criteria forpreserving water bodies; to assess strategies to improve hydropower implementation, such assmall hydropower; testing studies in pilot catchments of partner countries; promotion anddissemination of project outcomes among target groups all over the SEE Region countries.

In particular, the report “Handbook of innovative technologies to promote SHP” , which is part of theWork Package 5 – Common strategies to improve SHP implementation, is presented here.



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1. List of abbreviations

SHP Small Hydropower Plant

PMU Phasor Measurement Unit

WAMS Wide Area System Monitoring

Sp Pumping Station,

SpA Pumping Station for Water Supply,

SpC Pumping Station for Sewage,

SpM Pumping station for Irrigation,

Spm Mobile Pumping Station,

SE Water Cleaning Plant;

STA Water Treatment Plant,

BA Storage Pool



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2. Introduction

Handbook of Innovative Technologies presents, on one hand, a monitoring system of the hydraulic,mechanical and electrical parameters related to a SHP and, on the other hand, it presents a newconcept with regard to the possibility to catch the kinetic energy of a water stream.

Therefore, the first part shows the monitoring system of the SHP parameters implemented to aSHP on Arges river (one of the well hydropower developed rivers in Romania) – Mihailesti SHP,one of the most important also from the standpoint of the fact that it has a strategic importance forthe company Hidroelectrica, its owner. There are presented the equipment of the monitoringsystem, their arrangement within the power house, the connection between the equipment, and theinformation processing and presentation method. The system consists in modern equipment, is

portable and can be placed in any small hydropower plant.

Several small hydropower plants, having implemented this monitoring system, can beinterconnected and managed from a dispatcher center. Received parameters can be collectedwithin a data base and the hydropower plant operation can be analyzed. The most important issueis that the different failures, that can occur, can be analyzed and interpreted accurately, especiallythe electrical failures and that cannot be other way interpreted.

The second part presents potential sites for SHP implementation on Prut river (located at theborder between Romania and Moldavia), providing details on the kinetic energy potential of rivers.This is due to the fact that the innovative technology refers to the possibility of catching the riverkinetic energy and of its conversion into electrical energy, by means of kinetic turbines.

The micro hydropower plant is a complex technical system that includes constructive componentswith distinct functions: rotor-turbine that draws off a part of the water kinetic energy at its interactionwith the water flow; mechanical transmissions for the transformation of the converted energy;pumps and generators for useful power generation, etc. The conversion efficiency of the microhydroelectric power plant depends on the performances of each component.

Starting with the idea and up to the functional prototype in situ the main steps are as follows: thedesign of the functional concept of the micro hydroelectric power plant; the theoretical research ofthe factor of influence on the water kinetic energy conversion efficiency; the particular research anddesign of the working element for the water kinetic energy conversion efficiency; the research anddesign of the units participating in the transformation of converted energy into useful energy; the

manufacturing and separate experimental research on the units; the design and manufacturing ofthe micro hydroelectric power pilot-plant; the experimental research on the units as integraltechnical system and the evaluation of the similarity of functional and constructive parameters thathave been theoretically and experimentally determined; the introduction of partial modifications inthe project documentation; the development of the execution technologies and manufacturing ofthe micro hydroelectric power plant, as a final industrial product.

In the Annex there are presented new technologies developed for the catchment of the waterkinetic energy.



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3. Smart Measurements for Small Hydropower Plants (RO)Romania is rich not only in concentrated sources on energy but also on distributed onesrepresented by internal rivers flowing through long valleys several hundred kilometers long, Figure1. (1)

Figure 1 - Map of Romania with main rivers, major, medium and small hydro plants

In our case, on the studied river Arges, Figure 2, where were built a number of Small Hydro Plants,(SHP), based on different types of water turbines, Figure 3. Function of the head, available flowand power of the turbines, the best solution was chosen from Francis, Kaplan and Cross Flow(Banki) type. (2)

Figure 2 - River Arges with major and small hydro plants



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Banki Pelton Kaplan Francis

Figure 3 - H/Q and η /Q characteristics for small hydro turbines

As a first step for building an advanced Synchronous Measurements System on Arges River, wasthe pilot project at SHP Mihailesti, 20 Km outside Bucharest, Figure 4.

Figure 4 - Mihailesti small hydro plant with one Francis and two Kaplan turbines

This SHP belongs to Hidroelectrica SA and is composed of two, 5 MW/6KV Kaplan Turbine /Synchronous Generator Groups and one 450 KW/400V Francis Turbine/ Induction-GeneratorGroup, Figure 5, all of them operating in parallel through step-up voltage transformers with outputof 20KV, 50Hz.


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Figure 5 - Measurement diagram for Mihailesti SHP

Figure 6 - Arbiter Systems – Power Sentinel Phasor Measurement Unit

Through an underground feeder the generated electrical energy is sent to a distribution substationowned by ENEL SA Romania from where through a step-up transformers at 110 KV is sent by anaerial line to a 110/400 KV station belonging to TRANSELECTRICA SA, in Romanian National Gridand from there also to European neighbors, Figure 7.



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Figure 7 – Wide Area Monitoring System (WAMS)

Due to the fact that monitoring area covers large distances and even for lengths of lines of 300 Km,the information travelling with the speed of light needs 1 ms to be transferred from one point toanother. This corresponds to a delay of 18 electrical degrees for a 50 Hz power line. Taking intoconsideration the latencies added by Ethernet network (at least 4 -5 ms) the overall delay in datatransfer can reach a value close to 90 electrical degrees, which make it impossible to be used indifferential protection or in remote control.

In the case of distributed data acquisition in an electrical system the data obtained cannot be usedproperly as they are based on different individual local clocks. Synchronous measurementrepresents the only solution to solve this problem and is used successfully in transport powersystems. Optimization of distribution networks needs the real time knowledge of actual steady

state operation and dynamic transitions. In order to achieve this target a synchronizationtechnique has to be used and all the measurements have to be time tagged.

Such a commercial equipment which fulfils these request built on IEEE standard C37,118-TM2005, is called Phasor Measurement Unit (PMU), and is basically a data acquisition system ofthree phase voltages and currents sampled at 10 KHz, based on these data are calculated thefrequency, the per-phase rms values, active and reactive power, active and reactive energy,harmonics and THD, all this data is sent via different communication protocols, including internet,to the solicitant.

The precise time is obtained from Global Positioning Satellites, (GPS), as Coordinated UniversalTime (UTC). Such a distributed system is called: a Wide Area Measurement Systems (WAMS) and

represents the optimum way to solve also the power transfer and distribution problems. Thesesystems are intended for monitoring of wide networks by extensive measurement of synchronousphasors in important network points. WAMS consist of a network of GPS synchronized PhasorMeasurement Units (PMUs), system of tagged data transfer collected using various types ofcommunication, similar to that of SCADA systems. Using specialized software a server rearrangesall the information to the same moments of time and distributes the synchronized data throughInternet to all stake holders.

The PMU used in this project is an Arbiter Systems Power Sentinel which, offers as output in UTCtime, the three phase voltages and currents with 1 KHz sample time and all other results calculatedin numerical form, Figure 8. (3)



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a) b)

c) d)

Figure 8 - Data Collected From Phasor Measurement Unit 1 at Mihailesti SHP; a) Voltages, b)Currents, c) RMS Data, d) Phasors

Our Lab is connected to a Continental and UK network with a server in Slovenia. [www.elpros.si(4)]. In Figure 9 a) is a map of continental Europe where the PMUs are placed: Ljubljana, Slovenia;Dortmund, Germany; Almelo, Nederland, and Bucharest with the low voltage, frequency and

phasors data. In Figure 9 b) are presented the charts of low voltage, phase angle variation andfrequency in these four locations.



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a)

b)

Figure 9 - The PMUs in ELPROS network and representation of voltages, phasors, frequency in allfour acquisition points



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a)

b)

Figure 10 - Data collected from Mihailesti PMU on the output 20KV output line



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In Figure 10 is presented in detail the data collected from the PMU installed at Mihailesti: a)Positive sequence voltage, frequency; b) phase current magnitude, active power, reactive power.

Developing digital measurements control and protection for a power system, and verifying itsstability, it is necessary to estimate in real time the system parameters, and based on them tosimulate the dynamic of system operation. For the control of the synchronous generators from SHPMihailesti is necessary to use as reaction the state variables, which have to be synchronouslymeasured or observed. In order to realize this operation with a single data acquisition equipmentwas chosen a Reconfigurable Control and Monitoring System, a NI Compact RIO Programmable Automation Controller (Figure 11) GPS synchronized, for which we developed the necessarysoftware in LabVIEW graphical programming language (5). The NI CompactRIO system contains areal-time controller floating-point processor (RT) and an embedded user-programmable fixed pointFPGA (field programmable gate array) chip providing direct access to input/output (I/O) moduleswhich contain built-in signal conditioning and isolation. The program in the FPGA runs at 50 us

loop rate while that in the RT processor at 5ms only.

Figure 11 - National Instruments Compact RIO Programmable Automation Controller

For our application were chosen two 5 A, four phase current acquisition modules and one voltageacquisition module with 300V inputs. The acquisition modules have a resolution of 24 bits and amaximum sampling rate of 50 ksamples/s. As in the previous case the sampling is done at 10ksamples/s and a rms currents and voltages, powers, THD and phasors can be done for everycycle, in fixed point by the mean of a FPGA emulating the Power Sentinel PMU presented abovebut even with superior performances. The system is not using prefabricated embedded software asin the previous case but the one developed by the authors. More than that, the real time data forcurrents and voltages sampled at 10 kHz are re-sampled at 1 KHz and can be accessed viaInternet. The preliminary results recorded during a lab test using a 3x400V supply and a pure

resistive load are presented in Figure 12.



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a) Voltage, Current waveforms; Frequency

b) RMS Data



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c) Power

d) RMS Voltage, Current charts



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e) Voltage, Current Phasors

f) Voltage, Current Harmonics

Figure 12 – Power Monitoring Application Screenshots

The System can be used also for power transformers Differential Protection. In Figure 13 ispresented such a protection for a 20/110 KV transformer. The short circuit must be detected as



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soon as possible and the transformer disconnected from the AC Grid, otherwise the effects can bedisastrous. A Compact RIO controller with two current acquisition modules with four current inputs

each and two voltage modules with three inputs each is used in this case. In normal situation, thesum of the rated primary, the secondary currents plus the homo-polar one has to be equal with themagnetization current which generally is less than 10% of the rated current. If this condition is notfulfilled, it means that a short circuit is inside and the transformer should be disconnected. Aredundant solution is to measure the active powers on the two entries of the transformer and if theyhave contrary senses, means that total power is dissipated inside the transformer due to a shortcircuit.

Figure 13 - Diagram for the Differential Protection using a Compact Rio Equipment

One alternative for the acquisition of slow varying signals (temperature, flow, etc.) is to use awireless connection between the sensor and controller/measurement unit. Using a wirelessacquisition system instead of a wired one can be less costly in the case of retrofitting a hydro plant.In our study we had chosen the ZigBee technology. ZigBee wireless network can provide a

medium range communication (about one hundred meters) with fast connection of nodes to thenetwork and low power usage. For example a data acquisition node can be put in sleep state andat a specified interval powers up, connects to the network, acquires the signal and sends it to thecoordinator, than goes back to sleep mode. A ZigBee network can be formed in three ways: star,mesh and tree topology, or any combination of them. In Figure 14 is presented a network formedusing mesh and star topology.



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Figure 14 - ZigBee Network

In order to test this type of communication in SHP monitoring and control the Compact RIOcontroller was equipped with a SEA GMBh ZigBee Module (Figure 15) acting as coordinator.

Figure 15 - SEA ZigBee Module

As end-points the Digi Xbee PRO modules from DIGI were chosen. These modules include four

ADC channels with a sampling rate of about two samples per second.

Figure 16 - DIGI XBee ModuleOne of these modules was connected to a temperature sensor, while the other to a light sensor. In Errore.



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L'origine riferimento non è stata trovata. It is shown a screenshot of the application which records thedata received from both of them.

Figure 17 - Data monitoring application

The smaller power generators used are of induction types, generators which practically do notinfluence the system operation and the transient data are not necessary to be recorded. For thisreason for the monitoring of the Francis group installed at Mihailesti SHP, was chosen the CarloGavazzi Energy Management Modular Smart Power Quality Transducer (Figure 18) (6). Thistransducers computes all power related data, which is acquired and recorded on a server everysecond by custom developed SCADA software. This software includes also a WEB interface so allthe data can be visualized remotely. Screenshots of the developed application are presented inFigure 19.



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Figure 18 - Carlo Gavazzi Energy Management Smart Power Quality Transducer

a) Main Screen b) Online Values

c) Voltage Chart d) Current Chart



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e) Active Power f) Total Power

g) Reactive Power h) Voltage Total Harmonic Distortion

i) Current Total Harmonic Distortion j) Frequency

Figure 19 – Screenshots of SCADA Power Monitoring Application



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4. Innovative technologies to produce SHP (MOLD)

4.1. Identification and evaluation of potential sites for SHPimplementation (on river Prut)

A special area of interest consists in a more detailed study of the kinetic energy potential of riversof Moldova - Nistru, Prut and Raut, rivers with potential sites for SHP implementation. Given theimportance of SHP implementation for Republic of Moldova, the Centre for Development ofRenewable Energy Conversion Systems (CESCER) has been created at the Technical Universityof Moldova.

In order to perform the research on the rivers kinetic hydropower potential CESCER was equippedwith a measuring water velocity device Flow Probe FP201. First measurements were made on the

Prut River (figure 20) [1,4]. The choice of the sites was dictated by the following considerations: – Prut river is the border river between Republic of Moldova and Romania, which in

2007 became a part of the European Union;on both sides of the Prut river towns are located fairly dense, which may allow expansion of fieldresearch in regional projects funded by the European Union.

Prut, the first tributary of the Danube, startson the north - east coasts of theCarpathians at a height of 1580m and flowsthrough geographic plateau of Moldova.The total length of the river is 950km with awater catchment area of 28,400km2 and anaverage flow of 86m3/s. The distance of900km from its mouth, Prut river is a naturalborder between Republic of Moldova,Romania and Ukraine. Prut river sectionfrom its source through the mountainsregion has a relatively high flow.

Downriver the town of Chernivtsi (Ukraine)begins the portion of the river with anaverage flow discharge through a floodplainwith width 5–6km. The river banks are lowand floodable. River flow in the middle is

strong and during the floods the riverchannel changes.

Average flow region extends to Unghenihaving a length of 380km. Descendingportion of the Prut River, from Ungheni tothe river’s mouth has a length of 396km. Inthis region Prut flows through severalunimportant valleys with an average widthof 10–12km. On a large portion of low flowdischarge the river often floods. During theflooding on certain portions of the river

multiple channels are formed and during

Figure 20 – Map of energetic potential on Prut:

– Stoieneşti village, the site of micro hydro powerstation;

– Areas with a measured flow speed v>1m/s.



26

Ceremesul Alb). The left bank does not have important Carpathians tributaries, but in turn developsmore extensive associated rivers from Podolo–Moldav Plateau to the south (Turkey, Cerneava,

Sovita, Sada, Rarancea, Rakitna and Ringaci).

In order to select the potential sites for micro hydro power station installation the followingconditions must be fulfilled:

– the average water flow speed should be greater than 1m/s – the presence of nearby villages and economic agents, potential consumers of converted

energy; – necessity of a minimal capital investment for the construction of the anchoring system for

micro hydro power station.

In order to detect and evaluate the possible sites the following actions have been made: – a comprehensive analysis of the data provided by HidroMeteo Service;

– several expeditions in order to perform measurements on Prut River.

r. Gura-Lapusna (483)

r. Sarata(706)

Malul stang

r. Camenca (1230)

r. Cerneava (351) or. Kolomaia

or. Iaremcia

r. Ceremos (2558)

r. Baseu (930)

r. Jijia (5800)

r. Elanului (554)

r. Chineja (764)

Malul drept

1 6 0 0 0

8 0 0 0

0 1 6 0 0 0

2 4 0 0 0

K m2

8 0 0 0

2 0 0

4 0 0

6 0

0

sto.

or. Ungheni

or. Leova

or. Cahul

or.

Lipcani

Cernauti

r. Lopatinca (265)

r. Ciugur (724)

r. Narova (358)

r. Racovet (795)

8 0 0

9 6 7

k m

Figure 22 – Alimentation scheme for Prut river from right and left banks with tributaries waters.

Using the data provided by HidroMeteo Service and other sourses, the following locations havebeen initially identified as portions of Prut river with the flow speed greater than 1m/s:

Criva – Costeşti Sector : Lipcani, Şireuţ i;Costeşti – Ungheni Sector : Avrameni, Cobani, Taxobeni;Ungheni – Leova Sector: Ungheni, Costuleni, Bărboieni, Grozeşti, Pogăneşti;Leova – Giugiuleşti Sector : Châşliţ a – Prut, Colibaşi, Stoieneşti, Leca, Antoneşti.



27

Ungheni Sector . In Ungheni, nearby water intakes and pumping stations there have been

recorded average flow speeds 0.75–1.05m/s at a distance of 2.5–4.5m from river banks and depthof up to 1.5m. The measurements have been made between villages Măcăreşti–Fr ăsineşti(Ungheni district) and Bălăureşti (Nisporeni district).

Grozeşti, Zberoaia, Bălăureşti Sector . The narrowest place of the river in this sector is locatedform village Fr ăsineşti downriver to village Bărboieni, where the flow speeds of approximately 2m/shave been recorded. Because of this narrowing during the increased flow discharge periods thefloods often occur. In order to prevent flooding a bypass channel was built on the opposite bank.Electrical energy converted from the kinetic energy of water can be consumed by the nearbyborder guard station.

In the village Grozesti there were identified three possible sites with an increased flow speed, two

of them near the pumping stations and the other one located nearby the water supply pumpingstation (currently out of use due to the lack of electricity). Also, areas with higher flow speeds (1.2–1.4m/s) are located in the downriver areas of the village Grozesti.

In the village Bălăureşti relatively high flow speeds were recorded in the area of river bends, wheresmall bypass channels with a length up to a hundred meters can be build. Also, the site of nearbyirrigation pumping station, located on the river bank, can be considered.

Cahul – Giurgiuleşti Sector . Prut river portion from the village Giurgiulesti (mouth of the river) upto village Manta (Cahul district) there was investigated in the following locations: villages Chişliţ a-Prut, Slobozia Mare Văleni, Branza, Colibaşi, Vadul-lui-Isaac. Average flow speeds of 1.1–1.2m/swere recorded in the village Branza (at hydrometric station) downriver the mark nr.14. The river

width at the measurement sites is approximately 40–60m. The observation and measurement ofthe flow speeds were performed in the places with potential consumers of either converted energyor water for irrigation and water supply purposes. Along the river banks were located pumpingstations and water intake pipes. Measurements were made from river bank, river docks and boat(see figure 23).

The methodology of hydrometric observations and measurements. Water flow speed wasmeasured with Flow Probe FP 201 device from the river bank shore at a distance of 3–5m, from araft (in Leova, Ungheni, Taxobeni, Costesti, Bădrajii Vechi), from a river dock at a distance up to15m from the bank (Duruitoarea and Stoieneşti) and from a boat at a distance of 25m (Colibaşi).



28

Measuring depth of water flow speed waslimited to 1.5 m, equal to the possible

submersion height of the micro hydro powerstation blades. Water depth at the distance of5m from the river banks in different places at thetime of measurements varied between 1.8 to3.8m.

Investigations on the Prut River were made fromits mouth on the Danube (village Giurgiulesti)upriver to the border with Ukraine (village Criva)over a distance of 685km in the locations shownin Table 1. From the observations andmeasurements it was found that higher than

average water flow speeds are registered at thebends and in narrow places and some rarerapids. At the beginning and the end ofmeasurements of the depth or flow speed the

Figure 23 – Measurements of the flow speed onPrut river.

water level was measured that was correlated with previously recorded data from the hydrometricstations located in the area of interest. In Table 1 there were included sites on Prut River (nearbyvillages and cities) close to houses, gardens, agricultural lands, pumping stations, water storagetanks and other objectives, which may be potential consumers of energy converted from the kineticriver energy. In order to select potential sites for the installation of micro hydro power stationsadditional investigations were performed in the following sectors:

Sector: mouth of Jijia river–village Stoieneşti. River floodplain is weakly sinusoidal with a widthof 7–8.5km, and in the village Tochile-Raducani has a width of 5.2km. Floodplain on both sides, upthe village Pogăneşti is dammed. Downriver Sarata-Razesi village in the floodplain there arelocated small ponds and swampy areas, nearby the river banks dense forest changes in a bushyarea. The soil consists predominantly of clay and sands. The river channel is strongly sinusoidal, atshort distances smaller than 2-5km there are located sandbanks. Predominant width of the river is50–70m, 2km downriver the village Sarata, the river width is 120m and in Broscăeşti village itswidth is 40m. The river depth varies from 0.7 up to 7.3m, with prevailing depth of 3–5m. The riverbanks are steep with a height of 3–4m. The vegetation mostly consists of forests and bushes.

Sector: village Stoieneşti–Prut mouth on Danube. On this sector 160 km long, the floodplain is

weakly sinusoidal with an average width of 7 –8.5 km, at times increasing up to 12 km. Left slope ofthe floodplain is convex with a height of 80 –120m. In the village Branza left slope tends towards amore pronounced convexity and it is covered by steppe vegetation. Between village Zărneşti andcity Cahul there were terraces with steep steps, with a width of 1 –1.5km and length 6 –12km. Theslope and terraces are well formed mainly with clay soils.

Between villages Slobozia Mare and Cucoara the river channel is highly sinusoidal. Plain is mostlyunbranched. Nearby village Branza there is an island with a length of 24m, width 6m, height 1m.The width of the river is predominantly 60–80m, the largest width being 104m in the villageCrihana. Predominant river depth is 2–4m, the largest being 15m (2km upriver village Zărneşti).



29

Nr.

crt.

Location, villagespeed

, m/s

Border

marks

Nearby reference

points

Remark

1 2 3 4 5 6

1 Giurgiuleşti 0.8/1.0 1329-1334SpM, Spm, customs,

bridgeBorder guard station

2 Châşliţ a – Prut 1.0/1.2 1323 Bypass channel

3 Slobozia Mare 0.7/0.9 1320 Bypass channel Border guard station

4 Văleni 0.8/1.1 1299/1300 Rapids, SpM

5 Brânza 0.9/1.1 1296/1297 Spm Hydrometric station

6 Colibaşi 1.0 /1.3 1291-1294 SpM, Spm, BA Boat measures

7 Cahul 0.8/1.1 1270 SpA+inlet, bridge Border guard station

8 Goteşti 0.9/1.2 SpM, Sp2, BA

9 Stoieneşti 1.1/1.3

Spm–dock, bridge,

customs Border guard station10 Cantemir 0.8/1.1 SpA+inlet

11 Leca 1.0/1.2

12 Antoneşti 1.1/1.3

13 Leova 0.9/1.1 1188-1192 SpA,SpC,SE, raftBorder guard station,hydrometric station

14 Sârma 0.8/1.0 1181

15 Tochile–Răducani 0.9/1.1 1175, 1178 SpM

16 Sărata – Răzeşi 0.8/1.0 1168-1174 Border guard station

17 Pogăneşti 1.0/1.3 1160-1167 SpM, steep bend

18 Cioara 0.8/1.1 1156-1159 Sp1, Sp2

19 Dancu,Călmăţ ui 0.9/1.2 1153-1155 SpM, steep bend

20 Leuşeni 0.8/1.1 1145-1152SpM, steep bend,

costumsBorder guard station

21 Dr ănceni (Rom) 0.7/1.0 Bend Hydrometric station

22 Cotul Morii 0.8/1.1 1137 Steep bank, Sp Border guard station

23 Bălăureşti 0.9/1.2 1125-1126Sp1+BA,Sp2+BA,

bend

24 Zberoaia 0.8/1.1 1120 Bend

25 Grozeşti 1.0/1.3 1117, 1118Sp1,Sp2,SpA,

meanders

26 Bărboieni (sus) 1.1/1.5 1110, 1111Narrow width,

meandersLandslides

27 Fr ăsineşti 0.7/1.0 1109 Bend, bypass chann Border guard station1 2 3 4 5 6

28 Măcăreşti 0.7/1.0 1107 Meanders

29 Costuleni 1.2/1.5 1101Narrow width,

meanders

30 Valea Mare 0.8/1.1 1097Sp9, Sp10, SE(Ungheni city)

Border guard station

31 Ungheni 1.0/1.3 1077-1079SpA, STA, raft,

bridgeBorder guard station,

punct hidrometric

32 Sculeni 0.8/1.1 1045/1051Sp, bypass channel,

customs, bridgeBorder guard station

33 Medeleni 0.9/1.1 1055 Sp3, Sp4, meanders

34 Gherman 0.9/1.0 1042-1044 Sp5+inlet, Sp6(hill)35 Taxobeni 1.1/1.4 1035-1037 SPA(Făleşti city), raft Border guard station



30

36 Horeşti, Unteni 0.7/1.0 1031-1034 Landslides

37 Valea Rusului 0.8/1.2 1027, 1028 Sp, bend Border guard station

38 Călineşti 0.7/1.0 SpM+BA Border guard station39 Chetriş 0.8/1.1 1007 Sp1, Sp2, Sp3 Bridge r. Camenca

40 Bisericani 0.9/1.2 1003 SpM+priză Border guard station

41 Cobani 1.1/1.4 988SpA (Sugar factory

Glodeni)Border guard station

42 Avrameni 1.1/1.5 984 Steep bend

43 Br ăneşti 0.9/1.1 982 Sp1, Sp2+BA, Hydrometric station

44CHE Costeşti,

downriver0.9/1.2 2 turbines, small BA Border guard station

45 CHE Costeşti, upriver 0BA, dam, Sp,

customsBorder guard station

46 Duruitoarea 0.1/0.2 BA, dock Tributary r.Ciuhur

47 Bădrajii Vechi 0.2/0.3 960/961 Inlet SpAC+ST, AP Dam r.Racovăţ , Sp

48 Bădrajii Noi 0.3/0.5 956Border guard station,

pond, plate bankBorder guard station

49 Viişoara 0.6/0.8 953/954 Bypass channel Hydrometric station

50 Lopatnic 0.7/1.0 952/953 Bypass channel Tributary r.Lopatinca

51 Bogdăneşti 0.9/1.1 951Steep banks both

sidesBorder guard station

52 Gremeşti 0.9/1.2 948 Steep bank, quarry

53 Teţ cani 0.8/1.1 945 Mal abrupt, forrest Tributary r.Vilia

54 Pererâta 0.9/1.2938/939,

942Steep bank, bypass,

bend

55 Şireuţ i 1.0/1.2 934-936Steep banks,

meanders Hydrometric station

56 Lipcani 1.1/1.3 933 Steep banks, bridge

57 Drepcăuţ i 0.9/1.1 926 Forrest

58 Criva 0.8/1.0 924 Railway Northern point of Moldova

Table 1 – Water flow velocity on Prut river in different areas.

Legend to Table 1: Sp – Pumping Station, SpA – Pumping Station for Water Supply, SpC –Pumping Station for Sewage, SpM – Pumping station for Irrigation, Spm – Mobile Pumping Station,SE – Water Cleaning Plant; STA – Water Treatment Plant, BA – Storage Pool. Flow speed in m/s isspecified as follows: numerator at the depth of 1m; denominator at the water surface.



31

5. Elaboration of innovative technologies to produce SHP

5.1. Elaboration of floating micro hydropower plants for river waterkinetic energy conversion into electrical and mechanical energy

This issue is quite important for the execution of the renewable energy conversion system, forinstance, - of the micro hydroelectric power plant for the conversion of the river water kineticenergy into electrical or mechanical energy using the hydrodynamic effects. The micro hydropowerplant is a complex technical system that includes constructive components with distinct functions:rotor-turbine that draws off a part of the water kinetic energy at its interaction with the water flow;mechanical transmissions for the transformation of the converted energy; pumps and generators

for useful power generation, etc. The conversion efficiency of the micro hydroelectric power plantdepends on the performances of each component.

The main phases (in successive order) are as follows:- design of the functional concept of the micro hydroelectric power plant;- theoretical research of the factor of influence on the water kinetic energy conversion

efficiency;- particular research and design of the working element for the water kinetic energy

conversion efficiency;- research and design of the units participating in the transformation of converted energy into

useful energy;- manufacturing and separate experimental research on the units;

- design and manufacturing of the micro hydroelectric power pilot-plant;- experimental research on the units as integral technical system and the evaluation of the

similarity of functional and constructive parameters that have been theoretically andexperimentally determined;

- introduction of partial modifications in the project documentation;- development of the execution technologies and manufacturing of the micro hydroelectric

power plant, as a final industrial product.

The functional and constructive parameters of the hydrodynamic rotor, multiplier, generator andhydraulic pumps, adopted within the carried out research separately on each working element,demand experimental research of their functioning as an integral system, in real conditions. Theexperimental research on the units of the micro hydroelectric power plant as an integral system

aims at the increase of the conversion efficiency of the water flow kinetic energy into useful energyby introducing the relevant constructive modifications in the project documentation of the finalindustrial product.

5.1.1. Conceptual diagrams

To avoid the construction of dams, it is possible to use the river kinetic energy by utilizing waterflow turbines. This type of turbines can be mounted easily and are simple in operation. Theirmaintenance costs are rather convenient. The stream velocity of 1m/s represents an energydensity of 500W/m2 of the flow passage. Still, only part of this energy can be extracted andconverted into useful electrical or mechanical energy, depending on the type of rotor and blades.Velocity is important, in particular, because the doubling of water velocity leads to an 8 times

increase of the energy density. The section of Prut River is equivalent to 60 m 2 and its meanvelocity in the zones of exploration is (1-1,3) m/s, which is equivalent to approximately (30-65) kW



32

of theoretical energy. Taking into account the fact that the turbine can occupy only a part of theriverbed, the generated energy could be much

smaller. There are various conceptual solutions, butthe issue of increasing the conversion efficiency ofthe water kinetic energy stands in the attention ofthe researchers. The analysis of the constructivediversion of micro hydroelectric power plants,examined previously, does not satisfy completelyfrom the point of view of water kinetic energyconversion efficiency. The maximum depth ofblade’s immersion is about 2/3 of the blade height h in a classical hydraulic wheel with horizontal axle(Figure 24) [1,2,4]. Thus, only this surface of theblade participates at the transformation of waterkinetic energy into mechanical one. As well, thepreceding blade covers approximately 2/3 of theblade surface plunged into the water to the utmost(h’’ 2/3h’), that reduces sensitively the waterstream pressure on the blade. The blade, following

the one that is plunged into the water to its utmost, is covered completely by it and practically doesnot participate in the water kinetic energy conversion. Therefore the efficiency of such hydraulicwheels is small.

Insistent searches of authors have led to the design and licensing of some advanced technicalsolutions for outflow micro hydroelectric power plants. They are based on the hydrodynamic effect,generated by the hydrodynamic profile of blades and by the optimal blades’ orientation towardswater streams with account of energy conversion at each rotation phase of the turbine rotor (Figure25) [1, 2, 4]. To achieve this, it was necessary to carry out considerable multicriteria theoreticalresearch on the selection of the optimal hydrodynamic profile of blades and the design of theorientation mechanism of blades towards the water streams.

The main advantages of these types of microhydroelectric power plants are:

- reduced impact on the environment;- civil engineering works are not necessary;- the river does not change its natural stream;- possibility to produce floating turbines by

utilizing local knowledge.

Another important advantage is the fact that it ispossible to install a series of micro hydro powerplants at small distances (about 30-50m) along theriver course. The influence of turbulence caused bythe neighboring plants is excluded.

The results of investigations conducted by theauthors (on the water flow velocity in the selectedlocation for micro hydro power plant mounting, onthe geological prospects of the river banks in the location of installing the anchor foundation and onthe energy demands of the potential consumer) represent the initial data for the conceptual

development of the micro hydro power plants and the working element.

Figure 24 – Conceptual diagram of thewater wheel with rectilinear profile of

blades.

Figure 25– Conceptual diagram of the waterrotor with hydrodynamic profile of blades

with its orientation towards the waterstreams.



33

The conceptual development of the plant structures with hydrodynamic profile of the blades wasperformed on the basis of three conceptual diagrams:

- Micro hydropower plant with pintle and blades fixed on the vertical axles anchored by steelstructure;- floatable micro hydro power plant with pintle and blades fixed on the vertical axles;- floatable micro hydro power plant with horizontal axis and blades fixed on the horizontal

axles.In order to increase the conversion factor of water kinetic energy (Betz coefficient), a number ofstructural diagrams of floatable micro hydro power plants has been developed and patented [8-14].The micro hydropower plants comprise a rotor with vertical axis and vertical blades withhydrodynamic profile in normal section. The blades are connected by an orientation mechanismtowards the water streams direction. The rotational motion of the rotor with vertical axis ismultiplied by a mechanical transmissions system and is transmitted to an electric generator or to ahydraulic pump. The mentioned nodes are fixed on a platform installed on floating bodies. The

platform is connected to the shore by a hinged metal truss and by a stress relieving cable.

The selection of the optimal blades hydrodynamic profile is very important for functionaloptimization of micro hydro power plants. It will allow increasing the conversion factor (Betzcoefficient) due to the hydrodynamic buoyant force. As well, conversion increase is achieved byensuring the optimal position of blades towards the water streams at various phases of rotorrevolution, employing an orientation mechanism of blades. Thus, practically all blades (even thoseblades which move against the water currents) participate in the generation of the summary torque.Moving in the water currents direction, for torque generation the blades use both the hydrodynamicforces and the water pressure exercised on the blade surfaces. Moving against the water currentsdirection the blades use only the hydrodynamic lift force for torque generation. Due to the fact thatthe relative velocity of blades concerning the water currents is twice bigger, practically, at their

motion against the water currents, the hydrodynamic lift force is relatively big, and the generatedtorque is commensurable to the one generated by the water pressure. This effect makes the basisof all patented technical solutions. Next, six technical solutions of micro hydro power plants arepresented, comprising various basic nodes and conversion principles that have been patented.These technical solutions allow essential increasing of the river water kinetic energy conversioncoefficient. Full description of the most representative technical solutions and brief description ofthe conceptual diagrams of micro hydro power plants properties are given below.

5.1.2. Micro hydro power plant for river water kinetic energy conversioninto electrical Micro hydro power plant (figure 26) [9]

The turbine 1 comprises blades 2, executed with the hydrodynamic profile and mounted on theaxles 3, fixed by their upper part on the extreme ends of the bars 4, with the possibility to rotate

around their axles. The position of the blades 2 at angle to the direction of water flow is ensuredby the controlling mechanism 5. Platform 6 is consolidated additionally by a winch 7 fixed on thetruss that is mounted unshiftable on the shore pillar 8. The turbine 1 and the blades 2 are placed inthe river water flow. The floating bodies 9 and the hollow blades 2 themselves control the positionof turbine 1 and blades 2 concerning the water level.



34

Figure 26 – Floatable micro hydropower plant with blades orientationmechanism.

The multi-bladerotor is

connectedcinematically andcoaxially to theelectric generator11 by themultiplier 10. Thewinch 7 is usedfor turbine 1maintenancewhich factrequires itsremoval from the

water. The blade2 (figure 27) ispositioned underangle α towardsthe water flow; itchanges

depending on the blade position to the waterflow direction.

The components of force F , acting on theblade, are determined from the relationships:

2

2 x x

vF C S

,

2

2 y y

vF C S

, (1)

where: ρ is water density;v is the water flow linear velocity;s is the blade surface;Cx, Cy are lift and drag (resistance) coefficientsof the blade profile. Coefficients Cx and Cy

depend on the blade entering angle α (the

angle between the blade and the water flowdirection) and on the profile shape. The angleis determined either experimentally or bynumerical calculations.

Figure 27– Positioning of blades towards the watercurrents.

The torque developed by one blade is described by the equation;

(cos sin )2 2

y x

d d M F F F , (2)

where F τ is the projection of force F on the tangent drawn to the path of motion of the blade axis.

The summary torque includes the general component of the resistance force F h. The torquemoment generated by the turbine consists of the torques generated by each separate blade.Currently only one blade will not generate positive moment (it will generate a negative moment –the resistance one). Thus, the torque generated by the proposed turbine will be essentially bigger



35

than the torque produced by the existing turbines for the same geometrical (blades dimensions)and kinematical parameters of water. The proposed micro hydro power plant allows the

transformation of the water flow kinetic energy into mechanical or electrical energy with anincreased utilization coefficient of water energy.

In the floating micro hydro power plant (figure 28) [10] an additional centrifugal pump 2 ismounted on the resistance structure 1. It is connected cinematically to the multi-blade rotor spindle3 by belt transmissions 4 and 5. The electric generator 6 is connected to the multi-blade rotorspindle by belt transmissions 4 and 7. As well, the resistance structure 1 is connected to the shoreby the metal truss 8 and supporting cables with cross-ties 9.

Figure 28 – Floating micro hydropower plant with electric generator and hydraulic pump.

In the floating micro hydro power plant (figure 29, a) [11] the rotor 1 contains an odd number ofblades 2 that are fitted with the possibility of rotation on vertical axes O'–O' (Figure 29,b) mountedon the extreme end of each horizontal bar 3. On frame 4, in the front part (through which water

flows pass) a rigid bar 5 is installed on which, in front of the hydro turbine relative to the water flow

direction, a sensor 6 is fixed that determines the water flow direction and connects to the rotationgear 7. The water flow moves in the direction of vector V 0 (figure 29, b). Angle γ is the enteringangle of the blades formed by the hydrodynamic surface string and the working lines of the waterflow vector V 0 V 0 . The angle depends on the form of the hydrodynamic surface and on the positionin the plane surface. By changing the water flow direction due to the change of water discharge

and river bed, the water currents will divert by angle modifying the entering angle γ. To meet theangle of attack, optimal in terms of conversion, it is necessary to correct the position of all blades

by angle ± . When changing the water flow direction, the positioning of all blades 2 is corrected

simultaneously by angle ± using the rotation mechanism 7:

1,2 = ± . (3)



36

Figure 29 – Floating micro hydropower plant with influence compensation of water currents flowdirection change.

In the floating micro hydro power plant (figure 30) [8,13] a technical solution is proposedensuring the transverse stability of platform 1 of the floating micro hydro power plant that ismounted on floating bodies 2 and 3, placed on the same side (shore side of the rotor spindle 4).Due to the fact that the rotor 4 blades 5 are hollow, the hydrostatic Archimedes force of the blades

5 fulfills the role of the floating bodies (figure 30,a, b).

The analysis of the application points motion path of the Archimedes force F a (point N in fig. 30, c)has shown that the distance from this point to the plane that crosses the rotor spindle 4 ( O1-O1,figure 38, b) will differentiate depending on the positioning angle of the rotor. Thus, thesedistances, for the blades that are placed in the upper semiplane defined by axis O1O1-OO differfrom the distances of those blades placed in the lower semiplane. The migration of the points ofapplication of the Archimedes force causes the pitching moment:

M r =M as-M ad , (4)

where M Σ as is the summary moment developed by the Archimedes forces that react on the blades

currently located in the upper semiplane;M Σ ad is the summary moment developed by the Archimedes forces that react on the blades

currently located in the lower semiplane.

The summary moments developed by the Archimedes forces that react on the blades aredetermined by the relations:

M Σ as = ΣF ai · l si and M Σ ad = ΣF ai ·l di (5)

where F ai is the Archimedes forces that react on the blades 5 currently located in the uppersemiplane;

l si is the distance from the point of application of the Archimedes force that reacts on theblades 5 currently located in the upper semiplane;



37

Figure 30 – Micro hydropower plant with increased transverse stability.



38

l di is the distance from the point of application of Archimedes force that reacts on the blades

5 currently located in the lower semiplane.Distances l si and l di are calculated from the relation:

2 2 2 2 cos( ) M M l R c Rc , (6)

Where R is the rotor radius 4;C M is the distance from the point of application of the Archimedes force and the blade fixing

point to the turbine rotor;α is the angle formed by the blade chord and the water flow direction;φ is the angle formed by the rotor lever and the perpendicular direction on the watercourse.

To compensate the pitching moment M r, the rotor spindle 10 is settled in plane ' 1

' 1 OO at distance

e compared to the longitudinal axial plane of the floating bodies O1-O1 . Distance e is calculatedfrom the relation:

1

n

i

i

y

en

, (7)

where n is the number of rotor blades, and y i is the distance from the centre of application of Archimedes force on blade i up to the longitudinal axial plane (figure 30, c). For each distance, y i iscalculated by the relation:

360cos sin( ( 1) )

o

i M y c R in

, (8)

where R is the rotor radius;

C M is the distance from the point of application of the Archimedes force and the blade fixingpoint to the turbine impeller, Oi N i in figure 30,c;

n is the number of rotor blades.So, the distance e is calculated by the relation:

cos M e c , (9)

where α is the angle formed by the blade chord and the water flow direction.

Conclusion: To ensure the floating stability of the micro hydro power plants the rotor is mountedon the main structure with displacement e against the water stream. Thus, the micro hydro power

plants designed to be anchored on the left bank cannot be anchored on the right bank.

5.1.3. Design of the hydrodynamic rotor

5.1.3.1. Theoretical justification of the hydrodynamic profile selection ofthe blade in normal section

Let consider the symmetrical profile of the blade placed in a fluid stream that moves uniformly at

velocity V

(figure 31). In the fixing point O' of the symmetrical blade with lever OO′ let consider

two coordinate systems, that is: the system O'xy with axis O'y oriented in the direction of thevelocity vector V

, and axis O'x - normal for this direction; and the system O'x ′ y ′ with axis O'y ′



39

oriented to the lever direction O'O, and axis O'x ′ - normal for this direction. Point A corresponds tothe rear edge, and point B corresponds to the entering edge. The entering angle is the angle

between the chord AB of the profile and the direction of the velocity vector V

, and the positioningangle φ is the angle formed by the velocity vector direction and lever O'O

Figure 31 – Hydrodynamic profile blade.

The components of the hydrodynamic force F

in the directions O'x and O'y are named the lift

force and the resistance force:

21,

2 L L p

F C V S (10)

21,

2 D D p

F C V S (11)

where ρ is fluid density, V ∞ is flow velocity, S p=ch (c is the length of chord AB, and h is the bladeheight) represents the area of the blade lateral surface, and C L and C D are hydrodynamicdimensionless coefficients, called the lift coefficient and drag coefficient. The hydrodynamiccoefficients C L and C D are functions of the entering angle α , Reynolds number Re and thehydrodynamic shape of the blade profile. The components of the hydrodynamic force in thecoordinate system O'x ′ y ′ are

sin cos ,

cos sin .

x L D

y L D

F F F

F F F

(12)

The torque moment of the rotor spindle OO′ developed by blade i is

, ,r i xT F OO (13)

and the summary torque moment developed by blades is

1

, Npal

r ri

i

T T

(14)

where Npal is the number of rotor blades.



40

Generally, the hydrodynamic force has no point of application in the origin of the blade axessystem O′ so as it produces a resulting moment. The produced moment is determined by

comparing it to a certain point of reference. The point situated at distance ¼ of the chord from theentering edge B will be considered as point of reference. The moment, also called the pitchingmoment, is calculated according to formula

21,

2 M p

M C V cS (15)

where C M is the profile number of turns.

5.1.3.2. Determination of the hydrodynamic coefficients CL and CM.Plane potential (cyclic) motion

The profile chord is considered unitary for simplicity. Initially, the fluid is considered incompressible

and non-viscous, and its motion –plane and cyclic. In the case of an incompressible fluid in planemotion the velocity components ,V u v in point P(x,y) are given by the relations:

( , ) ,u x y x

( , ) ,v x y

y

(16)

where Ф is the potential (cyclic) motion that is obtained by overlapping the velocity uniform flow

( cos , sin )V V V

with a distribution of sources and a distribution of vortexes placed on the

profile C . In other words the potential is decomposed like:

,S V (17)

where the potential of the uniform flow is demonstrated by the formula:

cos sin ,V x V y (18)

the potential of the intensity source distribution γ (s) is given by formula

( )ln( ) ,

2S

C

q sr ds

(19)

and the potential of intensity vortex distribution q(s) is given by formula:

( ).

2

V

C

sds

(20)

In the relations (19, 20) s represents the measured distance of profile C , and (r, θ ) are the polarcoordinates of point P'(x,y) reported to the point on the contour corresponding to distance s (figure32).



41

Figure 31 – Fluid cyclic motion around profile .C

Therefore the potential in point P'(x,y) is given by formula:

( ) ( )( ') cos sin ln( ) .

2 2C C

q s sP V x V y r ds ds

(21)

To calculate the cyclic motion potential Ф the collocation method is used, namely: the boundary ofprofile C is approximated by a closed polygon

1

, N

j

j

C E

sides E j having their points (vertex) P j and P j+1 placed on C . The numbering of points starts from therear edge on the lower side in the direction of the entering edge, passing further to the upper side(Fig. 33). It is considered that the intensity of vortexes γ (s) distributed on profile C is constant atthe boundary having value γ , and the intensity of sources q(s) distributed on the profile is constantat each boundary element E j having value q j , where j=1,…, N . Specifying the above, equation (21)becomes:

1

cos sin ln( ) ,2 2

j

N j

j E

qV x V y r ds

(22)

The unknown being and , 1, , . jq j N

Figure 32 – Digitization of profile .C

Let consider the boundary element E j with points P j and P j+1 (Fig. 34). The normal and tangent unitvectors of the element E j are given in formulas:

( sin ,cos ),

(cos ,sin ),

j j j

j j j

n

(23)

where

1sin ,

j j

j

j

y y

l

1

jcos . j j

j

x x

l



42

Figure 33 – Boundary element . j E

The unknown γ and q j , where j=1,…, N from the relation (22), are determined from the boundaryconditions and Kutta condition. In the case of non-viscous fluid, the boundary condition is thesliding condition at the profile boundary that is watertight and rigid, that, in the particular case ofplane and potential motion of the incompressible fluid, is written as follows:

0,V n

(24)

where n

is the normal of the profile. It is necessary to satisfy the condition (24) in the points of

collocation. Points , j j j M x y – the centers of sides E j , are selected as points of collocation:

1 1, , 1, , .

2 2

j j j j j j

x x y y x y j N

Velocity components in the point of collocation M j are written by:

( , ),

v ( , ).

j j j

j j j

u u x y

v x y

Thus, condition (21) delivers N algebraic relations:

sin cos 0, 1, ,i i i iu v i N (25)

that are used to determine those N+1 unknown γ and q j , where j=1,…, N. Kutta condition willdeliver the final relation, namely:

1

, N E E

V V (26)

where

is the tangent versor of the boundary element. In our notations, condition (26) takes the

form:

1 1 1 1cos sin cos sin . N N N N

u v u v (27)

Velocity components in pointi M are determined by the contributions of velocities induced by the

distribution of sources and vortexes on each boundary element E j :



43

1 1

1 1

cos ,

sin ,

N N s v

i j ij ij

j j

N N s v

i j ij ij

j j

u V q u u

v V q v v

(28)

where , , ,s s v v

ij ij ij iju v u v are so-called induction (influence) coefficients. For instance, s

iju represents the

component of velocity direction x in point M i , induced by the unitary intensity source distribution

from the element j E . The induction coefficients can be calculated in the following way:

, 1

, 1

, 1

, 1

1ln cos sin ,

2 2

1 ln sin cos ,2 2

1cos ln sin ,

2 2

1sin ln cos ,

2 2

i j ijs

ij j j

ij

i j ijs

ij j j

ij

ij i jv

ij j j

ij

ij i js

ij j j

ij

r u

r

r vr

r u

r

r v

r

(29)

where βij is the angle formed by sides j iP M and

1i j M P , for i ≠ j , and βij = π , i,j=1,…,N , and r ij is the

distance between points M i and P j . Let substitute expressions (28) and (29) in the boundaryconditions (25) and in Kutta condition (27) to obtain the linear system N+1 of equations with N+1

unknowns: γ and q j , where j=1,…,N :

, 1

1

1, 1, 1 1

1

, 1, ,

,

N

ij j i N i

j

N

N j j N N N

j

A q A b i N

A q A b

(30)

where coefficients Aij and bi , i, j = 1,…, N+1 are calculated by formulas:

, 11 1sin ln cos , , 1, , ,

2 2

i j

ij ij ij ij

ij

r A i j N

r

, 1

, 1

1

1cos ln sin , 1, , ,

2

N i j

i N ij ij ij

j ij

r A i N

r

1, 1 1, ,

1, 1 , 1

1

1, ,

1sin sin

2

cos ln cos ln ,

N j j j Nj N j

j N j

j Nj

j N j

A

r r

r r

1, 1 , 1

1, 1 1

1 1, ,

1 1

1sin ln sin ln

2

cos cos ,

N j N j

N N j Nj

j j N j

j j Nj Nj

r r A

r r



44

1 1

sin , 1, , ,

cos( ) sin( ),

i i

N N

b V i N

b V V

and .ij i j

The linear system (30) will give the searched values: γ and q j , where j=1,…, N, that will help furtherto calculate the tangential components of velocity in the points of collocation M i ,i = 1,…, N. Letremind that the normal component of velocity in the points of collocation is null. The below relationgives the tangential component:

cos sin .i i i i iu u v

Let substitute the relation (28) in the above relation to obtain:

1 1 1 1

cos cos sin sin .

N N N N

s v s vi j ij ij i j ij ij i

j j j i

u V q u u V q v v

Consequently, the following relations will be obtained for the tangential components of velocity:

, 1

1

, 1

1

cos sin cos ln2

sin ln cos .2

N i ji

i i ij ij ij

j ij

N i j

ij ij ij

j ij

r qu V

r

r

r

(31)

Bernoulli equation 2 21 1

2 2

p V p V implies that

2 21 1.

2 2 p p V V

Thus, the local coefficient of pressure can be rewritten as follows:

2

221 .

12

p

p p V C

V V

(32)

Accordingly, the local pressure coefficient on the discretized contour profile can be calculated fromthe relation

2

, 1 ,i

p i

u

C V

(33)

where components iu are supplied by formula (31).

The hydrodynamic forces that react on the boundary element E j are obtained from the relationsrelations:

, 1

, 1

,

,

xj p j j j

yj p j j j

f C y y

f C x x

(34)

and the pitching moments reported to the point of reference , ,0 ,4ref ref

c x y are calculated by

formula:

1 1

,.

2 2 4

j j j j

m j xj yj

y y x x cc f f

(35)



45

The total force is the sum of contributions of each boundary element:

1

1

,

,

N

x xj j

N

y yj

j

F f

F f

(36)

and the lift coefficient and the moment coefficient are calculated as follows:

sin cos , L x y

C F F (37)

,

1

. N

M m j

j

C c

(38)

5.1.3.3. Selection of the optimal hydrodynamic profile of blades

The optimization of the hydrodynamic blade turbine performance demands blade optimalhydrodynamic profile. The numerical calculation methods, previously described, are used tocalculate the coefficients

, L ref C and

, D ref C for the symmetrical profiles from the library of NACA

aerodynamic profiles with a chord length c ref = 1 m. It should be remarked that the calculation

method converges for the entering angles α that do not exceed 20 25o o dependent on the

selected profile and the corresponding Reynolds number (Re = 1300000). For the entering anglesexceeding this critical value, the rates corresponding to a flat (plane) profile are considered. Someof the considered profiles are shown in figure 35: NACA 0012, 0016, 63018 and 67015. Figure 36

shows the hydrodynamic lift, L ref C and drag

, D ref C coefficients depending on the entering angle.

Taking into account the data from Fig. 36, the NACA 0016 hydrodynamic profile is being selected

as the reference profile. Subsequently, this profile will be optimized in order to increase the turbineperformance.

0.2 0.4 0.6 0.8 1

-0.3

-0.2

-0.1

0

0.1

0

0.2

0.3

Profil NACA 0012

X (m)

Y ( m )

0.2 0.4 0.6 0.8 1

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Profil NACA 0016

X (m)

Y ( m )

0.2 0.4 0.6 0.8

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Profil NACA 63018

X (m)

Y ( m )

0.2 0.4 0.6 0.8

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Profil NACA 67015

X (m)

Y ( m )

Figure 34 – Symmetric hydrodynamic profiles: NACA 0012, 0016, 63018 and 67015.



46

15 30 45 60 75 900

0.5

1

1.5

2Profil NACA 67015

Unghiul de atac, (Deg)

C L ,

C D

15 30 45 60 75 900

0.5

1

1.5

2Profil: NACA 63018


C L ,

C D

15 30 45 60 75 900

0.5

1

1.5

2Profil: NACA 0016


C L ,

C D

0 15 30 45 60 75 900

0.5

1

1.5

2Profil: NACA 0012


C L ,

C D

CL

CD

Figure 35 – Hydrodynamic lift LC and drag DC coefficients dependant on the entering angle for

NACA 0012, 0016, 63018 and 67015 profiles.

5.1.3.4. The torque moment and the forces applied on the multi-bladehydrodynamic rotor

The hydrodynamic coefficients for the NACA 0016 reference profile with chord length, for instance,

1,3 .c m , are calculated below. The coefficients corresponding to the profile with the chord length 1.3 m

are calculated from the relations:



47

,

2

,

,

1,3 ,

(1,3) ,

1,3 .

L L ref

M M ref

D D ref

C C

C C

C C

(39)

The values of the lift and drag coefficientsdependant on the entering angle α areshown in figure 37. Taking into account

these values, the angle 18o is selected

as the working entering angle.

The blade changes its entering angleduring its motion depending on the position(figure 38). Thus, in sector I the enteringangle (angle formed by the blade and water

flow) is 18˚; in sector II the entering angleshifts from 18˚ up to -18˚, but the bladedoes not contribute to the total momentdeveloped at the rotor shaft. In this sector,extended up to approximately 60˚, the

blade is carried freely by the water flow and its re-positioning takes place at an angle of -18˚ at theend of sector III. The entering angle is -18˚ in sector III. In sectors IV-VI the hydrodynamic effect isminimal and the blade has to be re-positioned from angle -18˚ to angle 18. In order to use thekinetic energy in the sectors IV-VI it is proposed to re-position the blade from -18 ˚ to 90˚ in sectorIV; in sector V the blade remains under an angle of 90 ˚, and in sector VI the entering angle returnsto 18˚. Knowing the values of the hydrodynamic coefficients

LC and D

C , the lift force L

F and drag

force D

F are calculated by the formulas (10) and (11), and the formula (12) supplies the

hydrodynamic force that reacts on the blade (figure 39).

0 10 20 30 40 50 60 70 80 900

0.25

0.5

0.75

1

1.25

1.5

1.75

2

2.25

2.5


C L ,

C D

Coeficientii CL si C

D in functie de unghiul de atac. Profil: NACA 0016

Lungimea palei1.3 m

Numarul Reynolds1300000

CL

CD

Figure 36 - Hydrodynamic lift LC and drag

DC

coefficients dependant on the entering angle forNACA 0016 profile.

0 30 60 90 120 150 180 210 240 270 300 330 360−4000

−3500

−3000

−2500

−2000

−1500

−1000

−500

0

500

1000

1500

2000

2500

3000

3500

4000Fortele care actioneaza pe pala , Profil:NACA 0016

Unghiul de pozitionare, (Deg)

F o r t e l e ,

( N )

Profil: NACA 0016

Viteza fluxului de apa = 1 m/s

Unghiul de atac = 18 Deg

Raza rotorului = 2 m

Numarul palelor = 5

Inaltimea palei = 1.4 m

Lungimea palei = 1.3 m

Modulul rezultantei

Componenta tangentiala

Componenta normala

Figure 37 – Blade position and workingareas.

Figure 38– Module, tangential component and normalcomponent of the hydrodynamic force of a rotor

blade depending on the angle of positioning.



48

The module of the hydrodynamic force F

that reacts on the blade, and its tangential and normalcomponents F x and F y , depending on the positioning angle (angle of sight) are shown in Fig. 39.

The following constructive parameters of the rotor (impeller) were considered:Rotor (Impeller) radius 2 ; R m

Height of the submersible blade 1,4 ; H m

Blade length (chord) 1,3 ;c m

Working entering angle 18 ;o

Number of blades 5. pal N

Figure 40 shows the moment,r iT developed by the blade depending on the positioning angle; the

moment is calculated by the formula (13). Figure 41 shows the total (sum) moment at the rotor(impeller) shaft T r Σ developed by all blades depending on the positioning angle. The total momentis calculated by the formula (14). Figure 42 shows the total moment T r Σ depending on the

positioning angle for three values of water flow velocity V ∞: 1 m/s, 1.3 m/s and 1.6 m/s. The graphof the number of turns C M,ref depending on the entering angle α is shown in figure 43.

0 30 60 90 120 150 180 210 240 270 300 330 360−5000

−4000

−3000

−2000

−1000

0

1000

2000

3000

4000

5000

6000

7000Momentul dezvoltat de o pala functie de unghiul de pozitionare

Unghiul de pozitionare (Deg)

M o m e n t , ( N

⋅

m )

Profil: NACA 0016




Numarul palelor = 5



0 30 60 90 120 150 180 210 240 270 300 330 3600

2000

4000

6000

8000

10000

12000

14000

Momentul total la arborele rotorului functie de unghiul de pozitionare

Unghiul de pozitionare (Deg)

M o m e n t , ( N

⋅

m )

Profil: NACA 0016




Numarul palelor = 5



Figure 39 – Moment,r i

T developed by the rotor

blade depending on the angle of positioning.

Figure 40 – Total momentr T developed by 5

blades at rotor shaft depending on the angle ofpositioning.

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.5

1

1.5

2

2.5

3

3.5

4

4.5x 10

4


M o m e n t , ( N

⋅

m )

Momentul total la diferite viteze

1 m/s

1.3 m/s

1.6 m/s

Figure 41 – Total momentr

T at rotor shaft

depending on the angle of positioning forvarious velocities of the water flow

Figure 42 – Number of turns, M ref C depending on

the entering angle for NACA 0016 profile



49

Taking into account the fact that the hydrodynamic force is not applied in the blade fixed coordinate

system O (figure 44) this force produces a moment of torsion called the pitching moment. This

moment is determined given the point of reference. Point P will be considered as the point ofreference situated at ¼ distance of the chord from the entering edge B (figure 44). For the workingvalues of the entering angle α = 18˚ it is obtained C M,ref = -0.026. Thus, from the relation (40)results that C M = 0.0439. The moment of torsion compared to the point P is

2139,92 ,

2 M p M C V cS N m (40)

where V ∞ = 1 m/s, c = 1.3 m and H = 1.4 m. In the system of coordinates O x y , the components

of the hydrodynamic forces are delivered by the relation (12). Applying the values F L and F D obtained previously we have:

1601,2 ,

413,8 .

x

y

F N

F N

(41)

Then

0,0249 25 . x

O P M F m mm (42)

In order to ensure the stability of the blade motion, the fixing point W should be selected in theinterval 25 mm O W H ,

wheremin max H H H . Values

H min and H max are taken underthe condition that the frictionalforce, appearing in thekinematical couples of the

orientation mechanism, mustbe minimal.

To determine the optimal working entering angle it is necessary to calculate the value of themoment developed by one blade and the total moment for several values of the entering angle,

namely: 15 , 17 , 18 , 20 ,o o o o (figure 45-46). In this context the entering angle for the blade with

hydrodynamic profile NACA 0016 is 18 .o

0 30 60 90 120 150 180 210 240 270 300 330

0

1000

2000

3000

4000

5000Momentul dezvoltat de o pala la diferite unghiuri de atac


M o m e n t , ( N

⋅

m )

15 Deg

17 Deg

18 Deg

20 Deg

0 30 60 90 120 150 180 210 240 270 300 330 3600.5

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7x 10

4 Momentul total la diferite unghiuri de atac


M o m e n t , ( N

⋅

m )

15 Deg

17 Deg

18 Deg

20 Deg

Figure 44 – Moment developed by the blade,r i

T

depending on the positioning angle for variousvalues of the entering angle 15 , 17 , 18 , 20 .o o o o

Figure 45 – Total momentr T depending on the

positioning angle for various values of theentering angle 15 , 17 , 18 , 20 .

o o o o

Figure 43 – Location of the blade fixing point.



50

Also, the performance of 3-, 4- and 5-blades rotor was analysed. The total moment developed by

the rotor shaft was calculated and the results are presented in figure 47.

0 30 60 90 120 150 180 210 240 270 300 330 360

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7x 10

4 Momentul total la diferite configuratii


M o m e n t , ( N

⋅

m )

3 pale

4 pale

5 pale

Figure 46 – Total moment r T developed at the 3-, 4- and 5-blade rotor shaft depending on the

positioning angle.

5.1.3.5. Optimisation of NACA 0016 hydrodynamic profile

In order to maximize the moment of torsion produced by the micro hydro power plant rotor, theoptimization of the hydrodynamic profile will be considered. The moment of torsion depends on thelift and drag hydrodynamic forces given by formulas (10) and (11). The hydrodynamic forcesthrough the hydrodynamic coefficients depend on the entering angle α, Re number and the shapeof the hydrodynamic profile. The hydrodynamic shape of the profile was selected from the NACAlibrary of 4 and 5 figures having as parameters (with account of the profile symmetry) only themaximal thickness. The entering angle constitutes the second parameter. The optimization aims atmaximizing the lift force and, at the same time, does not allow the pitching moment and theresistance force to take very big values. The following issue of optimization should be considered:

Maximize ( , ) L LC C

with constraints imposed to the coefficients DC and

M C , (43)

where θ is the maximum thickness and α is the entering angle. The values of the inferior andsuperior borders are determined, as follows: the negative maximum value for the pitchingcoefficient will correspond to the solution for the entering angle 0. The maximum value for theresistance coefficient will correspond to the solution for the entering angle α = 18˚ . Also, restrictions

have been added to the optimization parameters 10% 20% and 0 20o o . To find the

optimal values of function1

( , , )n

f f x x an iterative method is used:

As long as the demanded accuracy is not reached the solution will be,

( )i i i B s f x ,

1i i i i x x s , (44)



51

wherei are the multipliers and

i B are the definite positive approximations of the Hessian

function f . The partial derivation of function f related to the component i is approximated with

the help of the finite difference formulas:

( ) ( )( )

2

i i

i

f x he f x he f x

x h

, (45)

where ie is the basis vector.

The optimization is done by the MATLAB optimization soft: “Sequential quadratic programming algorithm with a line search and a BFGS Hessian update”. The quadratic sub-tasksare solved by modified projection method. The gradient of function ( , ) L L

C C is calculated by the

finite difference formulas with the constant pitch 410h . NACA 0016 profile was considered asthe initial profile (figure 48). The result of optimization is presented in Fig. 49. The results of thecarried out research were published in [1 - 5].

Figure 47 – NACA 0016 hydrodynamic rack profilestandard.

Figure 48 – NACA 0016 hydrodynamic rackprofile standard and the optimised profile.

In order to optimize the hydrodynamic

profiles of the blades a prototyping 5-axismachine has been purchased (figure 50).For the manufacturing of the prototypesof hydrodynamic blades in the frameworkof the current project several specialmodules are at purchasing stage. Thepurchased equipment will allow theprototyping, manufacturing and testing ofthe profiles sugested by modelling andcomputer simulations.

Figure 49 – Blades prototyping 5-axis machine



52

5.1.3.6. Floating stability of the micro hydropower plant

The micro hydro power plant is posted in the river water flow. The position of blades compared tothe water level is ensured by the Archimedes forces that react on the floating blades. The bladecavity generates the Archimedes force determined bythe relation

, AF Vg (46),

where is the water density, V is the interior volume of

the blade and g is the gravitational acceleration. Theanalysis of the path of motion (motion trajectory) of thepoints of application of the Archimedes force F A (pointsN i , i = 1, 2, 3, figure 51) has shown that the distancefrom these points to the rotor axis O will oscillatedepending on the positioning angle . Thus, for the

blades located in the superior semi-plane defined by thestraight line OO΄ these distances are different from therespective distances of the blades located in the inferiorsemi-plane.

This fact leads to the appearance of the pitchingmoment with respect to the axis of longitudinalsymmetry of the floating bodies:

, ,,r S I M M M (47)

where ,S M is the total moment developed by the Archimedes forces that react on the blades,currently located in the superior semi-plane, and

, I M is the total moment developed by the

Archimedes forces that react on the blades currently located in the inferior semi-plane.

The total moments developed by the Archimedes forces that react on the blades currently locatedin the superior and the inferior semi-plane are determined by the relation

, , , ,S A i A i M F D (48)

where, A iF are the Archimedes forces that react on the blades;

, A i D are the distances from the

point of application of the Archimedes forces to the rotor spindle, and the summarization is done forall blades located in the superior semi-plane. Similarly,

, , ,.

I A i A i M F D (49)

Distances, A i D are calculated by the formula:

2 2 2

,2 cos( ), A i A A i D R c Rc (50)

where R is the rotor radius; Ac is the distance between the point of application of the Archimedes

forces and the point of blade fixing to the rotor lever; is the angle formed by the blade chord

Figure 50 – Floating stability analysis.



53

AB and the direction of the water flowing, and i is the angle formed by the rotor lever and the

direction OO .

To compensate the pitching moment r M it is proposed to locate the rotor spindle in the plane

shifted at distance e compared to the plane of longitudinal symmetry of the floating bodies.

Distance e is calculated by the relation:

1 ,

pal N

i

i

pal

y

e N

(51)

where pal N is the number of rotor blades and i y is the distance from the central point ofapplication of the Archimedes force on the blade i till the plane of longitudinal symmetry (figure

51). For each blade, distance i y is calculated by the relation:

360cos sin( ( 1) ).

o

i A y c R in

(52)

Let introduce (52) into (52) and obtain:

cos Ae c (53)

The point of application of the Archimedes force on each blade is the centre of gravity (mass point)of the applied hydrodynamic profile, in our case NACA 0016 profile. The central point of application

of the Archimedes force system that reacts on a number pal N of the submersible blades will

describe a migration trajectory generated by the rotor revolution. The migration trajectory

generated by a complete revolution of 3- and 5-blade rotor represents closed curves described in

figure 52 (a) and figure 52 (b). One point on the closed curve represents the position of the central

point of application of the Archimedes force system corresponding to a concrete angular position of

the rotor.

To identify the technical solution ensuring the floating stability of the micro hydro power plant it is

−0.03 −0.01 0.01 0.03 0.05 0.07 0.09 0.11 0.13

0.22

0.24

0.26

0.28

0.3

0.32

0.34

0.36

0.38

X, (m)

Y ,

( m )

Traiectoria de migrare a punctului cA

−0.01 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

0.29

0.3

0.31

0.32

0.33

0.34

0.35

0.36

0.37

X, (m)

Y ,

( m )

Traiectoria de migrare a punctului cA necessary to estimate

the values of thedistance between thecentral point ofapplication of the Archimedes forcesystem and thelongitudinal symmetryaxis of the floating

Figure 51 – Migration trajectory of the central point of application of theArchimedes forces for the 3-blade (a) and 5-blade rotor (b).

bodies Figure 53 (a, b).shows



54

0 30 60 90 120 150 180 210 240 270 300 330 3

0.24

0.26

0.28

0.3

0.32

0.34

0.36


e ,

( m )

Distanta e

0.3296

0 30 60 90 120 150 180 210 240 270 300 330

0.29

0.3

0.31

0.32

0.33

0.34

0.35

0.36


e ,

( m )

Distanta e

0.3296

the distance edepending on the

positioning angle φ ofthe 3-blade (a) and 5-blade (b) rotor. It hasbeen stated that in thecase of 3-blade rotor,distance e takes valuescomprising

0,238mine m and

max0,363e m .

Figure 52 – Dependence of distance e of the central point of application ofthe Archimedes forces on the positioning angle of the 3-blade rotor (a)

and of 5-blade rotor (b).

And in the case of 5-blade rotor: 0,289mine m , andmax

0,363e m . Let calculate the mean value

of distance e depending on the positioning angle φ: for 3- and 5-blade rotors the same mean

distance 0,33med e m is obtained.

Conclusions:

1. To ensure the floating stability of the micro hydro power plant it is necessary that the spindle of3- and 5-blade rotor shifts from the axis of longitudinal symmetry of the floating bodies at rate

0,33med e m in the direction opposite to the water flow.

2. Micro hydro power plants anchored on the left bank differ from those anchored on the right bankby the spatial truss constructions and, in particular, by the constructional elements of the

hydrodynamic rotor shifted at rate 0,33 .med

e m

5.1.3.7. Turbulence and stability of the hydrodynamic rotor

Figure 54 shows the field of fluid velocities around NACA 0016 profile at entering angle 18 ˚ and theReynolds number calculated from the relation [2]:

Re ,cV cV

(54)

where the fluid density is3998,4 kg m at 20o

C,

the kinematical viscosity

is 6 21, 012 10 m s ,

and the length of theprofile chord is

1,3c m .

For the fluid flow rate

1 , 1,5 , 2V m s m s m s

the following values of theFigure 53 – Velocity field around NACA 0016 profile at the enteringangle18o

.



55

Reynolds number Re = 1284600, 1798400 and 2312300 are obtained. The transition andseparation of the boundary layer on the inferior and superior surfaces of the blade profile is shown

in figure 55. Points T.U. and T.L. stand for the points of separation from the laminar flow to theturbulent flow on the inferior C inf and superior C sup surfaces of the blade (figure 52). Respectively,points S.U. and S.L. represent the points of separation on the inferior and superior surface. In allcases it was observed that transition from the laminar flow to the turbulent flow takes place in theproximity of the point of stagnation, and the separation of flow from the profile surface is foreseenat an approximate 40-50% distance of the blade chord length. The transition from the laminar flowto the turbulent flow as well as the separation of the turbulent boundary layer will take place in theproximity of the rear edge on the inferior surface.

5.1.3.8. Design and manufacturing of the hydrodynamic rotor

The hydrodynamic rotor has been designed in the Autodesk MotionInventor software (figure 56 - 3blades rotor, and figure 57 - 5 blades rotor). Thehydrodynamic rotor is the main workingelement of the micro hydropower plant, whichconverts kinetic energy of the water flow andtransmit it via the kinematical linkage to theproduction units of electrical (generator 1)energy or mechanical (hydraulic pump 2)energy (figure 58).

From the point of view of its design, therotor comprises the main shaft 1 (figures 56,57), the casing with radial bars 2, on whichends the hydrodynamic profile blades 3 are

mounted with the help of node 4. The main

shaft 1 and the casing with the bars 2 aremounted removable. The hydrodynamic rotoris a spatial structure, strained complex withthe bending and twisting moments. Thecasing with radial bars are made of aluminiumalloy plates with calculated dimensions able toensure design positioning (calculated) ofblades with minimal deviations (the deflexion

of blade axles till 5 mm, the angle of twist ofthe radial bars 1o).

a. b.

Figure 54 – Point of separation for the flow velocities 1 m/s (a) and 2 m/s (b).

Figure 55 – 3-blade hydrodynamic rotor.

1 2 4

3

Figure 56 – 5-blade hydrodynamic rotor.

2 1 4

3



57

- Longitudinal axis of spatial housing is perpendicular to the water flow velocity vector;- Level of blades submersion meets the project rate (h = 1.4 m). Perpendicularity of the

hydrodynamic rotor shaft to the water mirror is ensured by changing the buoyancy of four floatingbodies, and the perpendicularity of the longitudinal axis of the spatial housing to the water flowstream vector is ensured through supporting cables secured to the anchoring rods. Thesubmersion level of blades with hydrodynamic profile h = 1.4 m is maintained by changing thebuoyancy of the four equal floating bodies.

Structural and functional parameters of hydrodynamic rotor, planetary multiplier, generator and lowspeed centrifugal pumps, determined separately for each working body, needs to be checked byexperimental investigations in real conditions of their operation in an integral technical system.

In this context, the time table of experimental research on the pilot station in field conditionsincludes:

1. study of diversity of water flow speed cadastre within the boundaries of rotor effectivesection (the width of the rotor blades and level of submersion) and assessment of the water flowenergy potential;

2. study of the influence of force factors on the stability of the hydrodynamic profile blades

positioning (angle of attack ) and the kinetostatic analysis of the blades positioning mechanism;3. study of energy and kinetic conversion efficiency parameters (for the electric generator

terminals and the input shaft of hydraulic pumps);4. study of kinematic parameters of hydrodynamic rotor and mechanical losses in the

kinematic chain (linkage);5. setting the influence of structural and functional parameters of hydrodynamic rotor on the

hydrodynamic effects and water turbulence flow mode under field conditions;6. study of functional characteristics of electrical generator and centrifugal pumps.

The experimental research of the integral technical system - hydrodynamic rotor coupledkinematically with component units of micro hydro power plants aims at increasing efficiency ofwater flow kinetic energy conversion into useful energy by identifying and, where necessary,introducing in the technical documentation of partial structural changes and, sometimes, ofconceptual and technical solutions adopted previously.

When developing industrial prototypes of micro hydropower plants for river water kinetic energyconversion the following criteria and requirements were taken into account:

- Exclusion of dam construction and of the negative impact on the environment, implicitly;- Lowest cost;- Simplicity of construction and operation;

- Increased reliability at dynamic overload in operating conditions;- Resistant composite materials, including conditions of high humidity;- Automatic adjustment of the micro hydropower plant platform position in conditions of water

level changing.

The technical solutions adopted in the process of micro hydropower plants design result fromtheoretical and experimental research presented in [1,2]. To justify the constructive and functionalparameters, additional numerical modelling and simulations were performed, using ANSYSsoftware CFX5.7, and the sub-software developed by the authors for MathCAD, AutodeskMotionInventor, etc., namely, simulation of the “fluid – blade” interaction and floating stability,hydrodynamic optimization of the blade profile in order to increase kinetic energy conversionefficiency of river water at its different velocities using 3-, 4- and 5-blades rotor. The efficient

operation of micro hydropower plants by individual customers for particular destination depends ontheir constructive configuration choices and on the functional characteristics of component units



59

Static description of the microhydro power plant. The blades 1 (figure 61) are connected to thehydrodynamic rotor 2 by roller friction bearings to ensure their orientation under a certain entering

angle .

Figure 60 – Micro hydropower plant with hydrodynamic rotor for river kinetic energy conversion intomechanical energy for water pumping (flow rate Q = 40m

3 /h, pumping height H =10...15 m)

(MHCF D4x1,5 M)

1.1. Blade with hydrodynamic 0016NACA profile; 2 – 3-blade rotor; 3 –planetary multiplier with multiplyingratio i=112 ; 4 – belt drive withmultiplying ratio i = 1,9; 5 - permanentmagnet generator (characteristics –see p. 5.4); 6. centrifugal pumpPSS40–10/50 (characteristics – pumpflow rate Q=40m

3 /h at pumping height

(10...15)m; 7 –plastic pontoons; 8 –guide; 9 – spatial housing.



60

Functioning principle. The river flowing water with the energy potential dependent on the flow velocitydrives the hydrodynamic profile blades 1 (figure 62), oriented continuously by the entering The hydrodynamicrotor 2 is mounted on the input shaft of the planetary multiplier 3 through an auxiliary shaft, which is fixed onthe bearings. The belt pulleys of the transmission 4 are mounted on the output shaft of the planetarymultiplier - the big one, and the small one - on the input shaft of the centrifugal pump 5. The hydrodynamicrotor 2 and blades 1, the multiplier 3, the centrifugal pump 5 and guides 6 are mounted on the spatial

housing 7, installed on thepontoons 8.

The micro hydropowerrotor 2 comprises threeblades oriented at an

entering angle , which isdependent on the waterflow velocity. In the areas

of blades 1 location,inefficient from the point ofview of river kinetic energyconversion, underhydrodynamic forces theblades 1 are repositionedat an angle of 90

o to the

currents of water or arecarried by the waterunhampered to the angle

= 0. Thus, the respectivepositioning of blades allowsthe increase of water

kinetic energy rateconverted into usefulenergy. As result, the watercurrents transmit a part oftheir kinetic energy to theblades 1, stressing them

under the hydrodynamic forces andreporting rotational motion with angular

frequency 1 and torque T 1 to the rotor 2.The summary torque T 1 , developed by thehydrodynamic forces and applied to the 3-blade rotor shaft at water flow velocities1.3, 1.6 and 1.8 m/s and at the entering

angle of blades = 18 o

, is presented infigure 63.

For rotor diameter D = 4 m, the submergedheight of blades h=1,4 m and length ofblade chord l = 1,3 m, the torque is:T 1 = 11938 Nm for water flow velocity V =1,3 m/s; T 1 = 18084 Nm for V = 1,3 m/s; T 1 = 22887 Nm for V = 1,8 m/s. Thecalculations of kinematics and liftingcapacity of all constructive elements as wellas of all functional and energy parameters

Figure 61 – Kinematics of micro hydropower plant MHCF D4x1,5 M.

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.5

1

1.5

2

2.5

3

3.5

4x 10

4


T ,

( n ⋅

m )

Momentul sumar T la diferite viteze, Profil:NACA 0016

v0=1.3 m/s

v0=1.6 m/s

v0=1.8 m/s

22887 N⋅ m

18084 N⋅ m

11938 N⋅ m

valoare medie

Figure 62 – Torque T 1 at the hydrodynamic rotor shaft with

NACA 0016 rofile blades.



61

of micro hydropower plant have been carried out for the torque value T 1 = 18084 Nm.

Rotor 2, rigidly coupled by means of auxiliary shaft with the input shaft of the multiplier 3, transmitsrotational motion to the last with angular frequency 1 and torque T 1. The multiplier reproduces the

rotor 2 revolutions up to 112 1

30n i (min ),

where i 1 represents the multiplying ratio of the multiplier

(i 1=112). Rotational motion at angular frequency 122

n( s )

30

is transmitted from the multiplier

input shaft via a transmission belt 4 of the centrifugal pump input shaft with multiplying ratio i 1 =

2,25 . As result, the input shaft of the centrifugal pump swivels with angular frequency 3 = 1i 1i 2 (s-1) and is stressed at torque:

1 1 2 r 3

1 2

T T ,( Nm )

i i

,

where: 1 is the multiplier mechanical efficiency ( 1 = 0,9);2 - is belt transmission mechanical efficiency ( 1 = 0,95);

r - mechanical efficiency of hydrodynamic rotor bearings ( 1 = 0,99).

According to the experimental research presented in [1,2] the mechanical efficiency of centrifugal

pump is 1 = 0,72 at rated speed frequency

133

30n 500 min .

The mechanical efficiency of the micro hydropower plant with hydrodynamic rotor for river waterkinetic energy conversion into mechanical energy, with account of all mechanical losses in the

linkage (at the hydraulic pump shaft) is:1 2 3 r 0,9 0,95 0,99 0,846.

Accordingly, the micro hydropower plant (MHCF D4x1,5 M) ensures the transformation into usefulenergy of 84,6% of the kinetic energy potential of the flowing water transmitted to thehydrodynamic rotor.



62

Figure 63 – Industrial prototype of the microhydropower station for the river kinetic energyconversion into electrical and mechanical energies (diameter of rotor d = 4m, submersed height of

the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 ME).

According with obtained results the industrial prototype of the microhydropower station for the riverkinetic energy conversion into electrical and mechanical energies (diameter of rotor d = 4m,submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 ME) wasproduced (figure 64). Now is installed on the river Prut, v. Stoieneşti, Cantemir for testing in realconditions (figure 65).

Figure 64 – Industrial prototype of the microhydropower station for the river kinetic energyconversion into mechanical energy installed on the river Prut, v. Stoieneşti, Cantemir.

5.2.2. Micro hydropower plant with hydrodynamic rotor for river waterkinetic energy conversion into electrical and mechanical energy (MHCFD4x1,5ME)

The micro hydropower plant MHCF D4x1,5 ME for river water kinetic energy conversion intoelectrical and mechanical energy (figure 66) is polyfunctional and can be utilised for electricallighting of streets, heating, water pumping in drip irrigation systems, and also for drainingagricultural lands adjacent to rivers.

Rigging the NACA 0016 profile blades 1 in the hydrodynamic rotor 2 and its attachment to themultiplier input shaft 3 is done similar to micro hydropower plant MHCF D4x1, 5 M. Kinematic andconstruction peculiarities of MHCF D4x1,5 ME are as follows: rotational movement of the



63

hydrodynamic rotor 2 (Figure 67) with an angular frequency (velocity) 1, by means of multiplier 3and belt transmission 4 with effective multiplying ratio i = 212.8, is multiplied to the operating

angular frequency of the permanent magnet low speed generator 5:3=1i 1 (s

-1).

Torque T 3, applied to rotor 5, is:

1 1 2 r 3

T T ,( Nm )

i

,

where: 1 is multiplier mechanical efficiency ( 1 = 0,9);

2 – is belt transmission mechanical efficiency ( 1 = 0,95);

r – mechanical efficiency of hydrodynamic rotor bearings ( 1 = 0,99).i – effective multiplying ratio equal to the multiplying ratios product of the planetary multiplier

and belt transmission



64

Figure 65 – Micro hydropower plant with hydrodynamic rotor for river kinetic energy conversion intoelectrical and mechanical energy (rotor diameter D = 4 m, submerged height of blade h = 1,4 m,

length of blade chord l = 1,3 m) (MHCF D4x1,5 ME)

The electric energy produced by the permanent magnet generator 5 (figure 67) can be utilised to satisfy theenergy needs of the private consumers and, as well, to supply the centrifugal pump 6 (model CH 400) withelectrical energy in order to pump water in drip irrigation systems or for drainage of agricultural land adjacentto river (with relocation of the centrifugal pump 6). In the case of electric energy production, with account ofmechanical losses both in the micro hydropower plant linkage and in the permanent magnet generator, theefficiency of energy utilisation at generator’s terminals is,

1 2 r g 0,9 0,95 0,99 0,87 0,736,

And in the case of water pumping (at the centrifugal pump shaft) the efficiency is:1 2 r g me 0,9 0,95 0,99 0,87 0,91 0,67,

1. Blade with hydrodynamic NACA0016 profile; 2 – 3-blade rotor; 3 –planetary multiplier with multiplyingratio i=112 ; 4 – belt drive withmultiplying ratio i = 1,9; 5 - permanentmagnet generator (characteristics –see p. 5.4); 6. centrifugal pump CH –400 (characteristics – pump flow rateQ=(20-40)m

3 /h at pumping height

15...32m); 7 –plastic pontoons; 8 –guide; 10 – space housing.



65

where: g is the

generator efficiency;me is the

efficiency of thehydraulic pumpelectromotor.

Thus, the microhydropower plantMHCF D4x1,5 MEensures thetransformation intouseful energy of73,6% and 67% of the

energy potential offlowing water, pickedup by thehydrodynamic rotor, inproducing electricalenergy and,respectively, in waterpumping.

5.2.3. Micro hydropower plant with hydrodynamic rotor for river waterkinetic energy conversion into electrical and mechanical energy atsmall speeds (MHCF D4x1,5ME)

Micro hydropower plant MHCF D4x1,5 ME (figure 68) is designed to convert river water kineticenergy into electrical and mechanical energy, by utilising low speed permanent magnet generator5 (n = 375 min-1) and three-stage low speed centrifugal pump (PSS 40-10/50 (n = 500 min-1) 7designed, in particular, for the micro hydropower plant and manufactured at „Hidrotehnica” S.A.,Chişinău. Research results and functional characteristics of the low speed pump are presented in[1,2].

Kinematics and functional principle of the micro hydropower plant are analogic to the microhydropower plant presented above (figure 67). Constructive peculiarities of this micro hydropowerplant refer, in particular, to the driving mechanism unit of the centrifugal pump (fig. 69) and to thesupply of the pump low speed electromotor 2 from the permanent magnet low speed generator 5(figure 68). This design configuration can be used both to meet the needs of irrigation by pumpingwater at relatively low heights (10 ... 15) m (e.g. over the river dam) and to perform the drainingworks of the land adjacent to the river. When the micro hydropower plant is used for drainingworks, the centrifugal pump driving mechanism (Fig. 70) is relocated from the spatial housing ofthe micro hydropower plant to the floating platform in the flooded area of agricultural land adjacentto the river.

Water current

Figure 66 – Kinematics of micro hydropower plant MHCF D4x1,5 ME.



68

planetary multiplier 1 through toroidal coupling 2 and housing 4 for taking over the reactive momentof torsion.

Figure 70 – Micro hydro power plant with hydrodynamic rotor for river water kinetic energyconversion into electrical energy (5-blade rotor diameter D = 4 m, submerged height of blade h = 1,4

m, length of blade chord l = 1,3 m).

1. Blade with hydrodynamicNACA 0016 profile; 2 – 5 bladerotor; 3 – planetary multiplier withmultiplying ratio i=112 ; 4 –permanent magnet generator

(characteristics – see p. 5.3); 5 –plastic pontoons; 6 – guide; 7 –spatial housing.



69

Dependence of summary torque T 1 applied tothe 5-blade rotor shaft depending on water flow

velocity (V = 1,3...1,8 ) m/s is presented infigure 72. Kinematic and lifting capacitycalculations of all structural elements, includingfunctional parameters and technicalcharacteristics of micro hydropower plants havebeen carried out for the torque value T 1 = 19893Nm, corresponding to the water flow velocity V= 1,3 m/s (maximum velocity specified for Prut,Dniester and Raut rivers).

Efficiency of the kinetic energy transmitted bythe water flow to the hydraulic rotor can be

considered (at the permanent magnet generatorterminals):

1 r g 0,9 0,99 0,87 0,775 .

In conclusion, we state that micro hydropower plant MHCF D4x1, 5E ensures the transformation of77.5% of the flowing water potential energy into useful electrical energy transmitted to thehydrodynamic rotor.

According with obtained research results the industrial prototype of the microhydropower station forthe river kinetic energy conversion into electrical and mechanical energies (diameter of rotor d =

4m, submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 E) wasproduced (figure 73).

Figure 72 – Industrial prototype of the microhydropower station for the river kinetic energy

conversion into electrical energy (diameter of rotor d = 4m, submersed height of the blade h = 1,4m,length of blade l =1,3m) (MHCF D4x1,5 E)

0 30 60 90 120 150 180 210 240 270 300 330 3600

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5x 10

4


T ,

( n ⋅

m )

Momentul sumar T la diferite viteze, Profil:NACA 0016

v0=1.3 m/s

v0=1.6 m/s

v0

=1.8 m/s

19893 N⋅ m

38137 N⋅ m

30133 N⋅ m

Valoare medie

Figure 71 – Torque T1 at the shaft of 5-bladeh drod namic rotor with NACA 0016 rofile



70

6. Summary and Conclusions

The paper presents a modern monitoring system of the hydraulic, mechanical and electricalparameters related to a SHP and also a new concept with regard to the possibility of catching thekinetic energy of a water stream.

The monitoring system of the SHP parameters has been implemented to a SHP on Arges river,here being presented the equipment of the monitoring system, their arrangement within the powerhouse, the connection between the equipment, and the information processing and presentationmethod. The paper presents also the fact that several small hydropower plants, having

implemented this monitoring system, can be interconnected and managed from a dispatchercenter. The most important issue is that the different failures, that can occur, can be analyzed andinterpreted accurately, especially the electrical failures and that cannot be other way interpreted.

As innovative technology for the catchment of the water kinetic energy it is presented a kineticturbine, completely new, of last generation, fully designed and manufactured by the technicalUniversity of Moldavia and tested in situ in Prut river (located at the border between Romania andMoldavia).

In the Annex there are presented new technologies developed for the catchment of the waterkinetic energy.



71

Annex

FREE FLOW TURBINE – VERDANT POWER

-a three-blade horizontal-axis turbine designed to capture energy from both river and tidal currents

-the turbines are installed and operate fully under water, invisible from the shore

-spun slowly and steadily by underwater currents, the turbine’s rotor drives a gearbox, which in turndrives a grid-connected generator

-the gearbox and generator are encased in a waterproof streamlined nacelle mounted on a pylon

-the pylon assembly has internal yaw bearings allowing it to pivot the turbine with the direction ofthe river’s currents

-the pylon is bolted via an adjustable adapter to a pile fixed to the river bottom

-the turbine will operate below 1 m/s but for economic efficiency it recommends velocitiesgreater than of 2 m/s and water depths of at least 6.5 m

Figure 73 – Free flow turbine, Verdant Popwer



72

FREE FLOW TURBINE – UEK Corporation Underwater Electric Kite

-the system employs two axial-flow turbines in a “side-by-side” configuration. Each turbine consistsof five blades that dive a single internal generator housed within the nacelle.

-the system incorporates an augmenter ring that is integral with rear edge of the shroud. Theaugmenter ring extends outwardly with respect to the axial alignment of the turbine shafts anddeflects the flow of water about the shroud. This creates a low pressure zone of the rear of theshroud that “pulls” water through the turbine blades at a velocity greater than that of the normalsurrounding flow of water.

-the unit is positively buoyant and is secured to the river bed by a single anchorage system using acable bridle. When flown as a kite the angle of attack is altered by a patented ballasting systemthat shifts a weight forward and back in the keel. Keeping a controlled operational depth, the unitsare not affected by the surface effect of the large waves or navigation. Lateral positioning controls

permit the units to stay in the core of current.-the turbine is designed to operate in river, tidal or ocean currents

-various models exist from 2 m to 5 m and operate in extremely low velocities of 0.2 m/s or less

Figure 74 – Free flow turbine, UEK Corporation Underwater Electric Kite

FREE FLOW TURBINE – SWAN TURBINE

-the unit is a three-bladed axial flow turbine

-a gearless low speed generator offers a high efficiency over a range of speeds with minimalmaintenance demands through the use of novel structural electromagnetic topologies

-a simple, robust and serviceable yawing mechanism is used for maximum flow capture



73

Figure 75 – Free flow turbine, Swan turbine

FREE FLOW TURBINE – GORLOV HELICAL

-a cross-axis turbine consisting of one or more helical blades that run along an imaginarycylindrical surface of rotation like a screw thread

-the helical airfoil blades provide a reaction thrust perpendicular to the leading edges of the bladesthat can pull them faster than the fluid flow itself

-the GHT allows a large mass of slow water to flow through, capturing its kinetic energy andutilizing a very simple rotor

-it can be assembled vertically, horizontally or in any other cross-axis combination using commonshaft and generator for an array of multiple turbines

-generating capacity is proportional to the number of modules

-in its vertical orientation the generator and gearing can easily be positioned above water

-the standard unit is 1 m diameter by 2.5 m in length

-it starts producing power at approximately 0.6 m/s.



74

Figure 76 – Free flow turbine, Gorlov helical turbine

FREE FLOW TURBINE – MILLAU VLH (VERY LOW HEAD TURBINE)

-installed capacity 410 kW

-commissioned on March 19, 2007

-a DN 4500 (runner diameter 4.5 m).

-the 410 kW max nominal power at grid was reached at the nominal speed of 37 rpm

-very smooth, vibration-free and silent operation (one must touch the machine to find out whether itis operating)

Figure 77 – Free flow turbine, Millau VLH



75

7. ReferencesReferences (RO)

1. Cojocar, Mihai. Hidroconstructia 2005. 2005.2. Pavel, Dorin. Masini Hidraulice. Bucuresti : Editura Energetica de stat, 1965.3. Arbiter Systems. Model 1133A Power Sentinel GPS-Synchronized Power Quality/Revenue Standard -Operation Manual.4. www.elpros.si. UniFusion. ELPROS. [Online] ELPROS. http://www.elpros.si/eng/UF_base.htm.5. National Instruments. NI cRIO-9022 Operating Instructions and Specifications.6. Carlo Gavazzi. PQT H Smart Modular Network Power Quality Transducer - Instruction Manual.7. Boyle, Godfrey. Renewable Energy - Power for a Sustainable Future. s.l. : Oxford University Press.8. Silviu, Folea. LabVIEW - Practical Applications and Solutions. s.l. : InTech, Croatia, 2011.9. Alexandru Fransua, Razvan Magureanu. Electrical machines and Drive Systems. s.l. : Technical Press,Oxford, UK, 1984.10. Aquatic Renewable Energy Technologies – AQUARET , Leonardo da Vinci, Project No: IRL/06/B/F/PP-153111, 2006, www.aquaret.com.

11. Websites: www.vlh-turbine.com, www.swanturbines.co.uk, www.uekus.com,www.verdantpower.com, www.gcktechnology.com, en.wikipedia.org

References (MOLD)

Monographs:1. I. Bostan, V. Dulgheru, I. Sobor, V. Bostan, A. Sochirean. Renewable energy conversion systems: / - Ch. :Tehnica-Info, 2007. – 592pp.2. Bostan, V. Dulgheru, V. Bostan, R. Ciupercă. Anthology of inventions: renewable energy conversionsystems: / - Ch.: Bons Offices SRL, 2009. – 458pp.3. Jula A., Mogan Gh., Bostan I., Dulgheru V. et al. ECOMECA – ECO- mechanical engineering. Braşov,Publ. House of „Transilvania” University, Braşov, p.324.4. BOSTAN, I.; GHEORGHE, A.; DULGHERU, V.; BOSTAN, V.; SOCHIREANU, A.; DICUSAR Ă, I.

Conversion of Renewable Kinetic Energy of Water: synthesis, Theoretical Modeling, and ExperimentalEvaluation. Energy Security: International and Local Issues, Theoretical Perspectives, and Critical EnergyInfrastructures (NATO Science for Peace and Security Series - C: Environmental Security). 2011. Publishedby Springer, p. 125-177. ISBN 978-94-007-0718-4

Article:5. Bostan I., Dulgheru V., Sobor I., Bostan V., Sochirean A. Valorisation of renewable energy // ENERG VI:Energy, Environment, Economy, Resources, Globalization. Publ. AGIR, Bucureşti. P. 152-205. ISBN 978-973-720-263-5.6. Bostan I., Bostan V., Dulgheru V. Microhidro stations / Seminar addressed to hydropower stakeholders inMoldova - SEE HYDROPOWER - clear water, clean energy (SEE - South East Europe) 24.03.2010.7. Dulgheru V. Utilisation of renewable energy sources - wind, solar and hydro in the Republic of Moldova.Meridian Ingineresc, nr. 3, 2009. P. 63-69.

8. Bostan I., Dulgheru V. Renewable energy conversion systems – one of basic element for sustenabledevelopment of society . // Pro-Active Partnership in Creativity for the Next Generation. Proceedings: 32st

ARA Congress. - Sibiu, 2009. - P. 78-82.



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Patents:9. PATENT 2981 (MD), CIB B 63 B 35/44; E 02 B 17/00. Hydraulic station / I. BOSTAN, V. Dulgheru, V.Bostan. R. Ciupercă. Publ. BOPI – 2006. - Nr. 2.10. PATENT 2991 (MD), CIB F03 B 7/00. Hydroelectric station / I. BOSTAN, V. Dulgheru, V. Bostan, O.Ciobanu, A. Sochireanu. Publ. BOPI – 2006. - Nr. 2.11. PATENT 2992 (MD), CIB F 03 B 7/00. Hydraulic station / I. BOSTAN, V. Dulgheru, A. Sochireanu, V.Bostan, O. Ciobanu, R. Ciobanu. Publ. BOPI – 2006. - Nr. 2.12. PATENT 2993 (MD), CIB F 03 B 7/00; F 03 B 13/00. Hydraulic turbine / I. BOSTAN, V. Dulgheru, V.Bostan, A. Sochireanu, N. Trifan. Publ. BOPI – 2006. - Nr. 2.13. PATENT 3104 (MD), CIB F 03 B 7/00: F 16 H 1/00. Hydraulic station / I. BOSTAN, V. Dulgheru, V.Bostan, A. Sochireanu, O. Ciobanu; R. Ciobanu, I. Dicusar ă. Publ. BOPI–2006. -Nr. 7.14. PATENT 3845 (MD), CIB F 03 B 13/00; F 03 B 7/00; F 03 B 13/10; ; F 03 B 13/22; ; F 03 B 17/06.Hydraulic station / I. BOSTAN, V. Dulgeru, V. Bostan, A. Sochireanu, O. Ciobanu, R. Ciobanu. Publ. BOPI –2009. - Nr. 2.15. PATENT 3846 (MD), CIB F 03 B 13/00; F 03 B 7/00; F 03 B 13/18; ; F 03 B 13/22; ; F 03 B 17/06.Hydraulic station with horizontal axle / I. BOSTAN, A. Gheorghe, V. Dulgheru, V. Bostan, A. Sochireanu, O.Ciobanu, R. Ciobanu. Publ. BOPI – 2009. - Nr. 2.

Presentation on the International Salon of Research and Innovations16. Bostan Ion, Dulgheru Valeriu, Sobor Ion, Bostan Viorel, Sochireanu Anatol, Crudu Radu, Guţ u Marin,Ciobanu Oleg, Ciobanu Radu, Trifan Nicolae. Industrial prototype of mini hidropower station for flowwater kinetic energy conversion. Salon des Inventions, Geneva,- Palexpo, 6 au 10 avril 2010 (Silvermedal). 17. Bostan Ion, Dulgheru Valeriu, Sobor Ion, Bostan Viorel, Sochireanu Anatol, Crudu Radu, Guţ u Marin,Ciobanu Oleg, Ciobanu Radu,Trifan Nicolae. Industrial prototype of mini hidropower station for flowwater kinetic energy conversion. XIIIth Moskow International Salon of Research and Innovations ARHIMED-2010. 30.03..02.04.2010 (Gold medal).

18. Bostan I. (MD), Dulgheru V. (MD), Bostan V. (MD), Ciobanu O. (MD), Ciobanu R. (MD), Sochireanu A.(MD), Dicusar ă I. (MD), Trifan N. (MD). Industrial prototype of mini hidropower station for flow waterkinetic energy conversion into electrica land mechanical energy. (DIPLOM Ă şi Medalia de aur. PremiulSpecial al Asociaţ iei Inventatorilor din Zagreb). EUROINVENT"-European Exhibition of Creativity andInnovation-Iaşi, România. 07..09.05.2010 (Gold medal).19. Bostan Ion, Dulgheru Valeriu, Bostan Viorel, Sochireanu Anatol, Ciobanu Oleg, Ciobanu Radu, Dicusar ă Ion, Trifan Nicolae. Industrial prototype of mini hidropower station for flow water kinetic energyconversion into electrica land mechanical energy . International Salon of Research and Innovations,INVENTICA 2010, XIVth edition, 9 - 11 June 2010 (Gold medal).20. Bostan Ion, Dulgheru Valeriu, Bostan Viorel, Sochireanu Anatol, Ciobanu Oleg, Ciobanu Radu, Dicusar ă Ion, Trifan Nicolae. Industrial prototype of mini-hydropower station for flow water kinetic energy conversion.EURECA 2009, Bruxel (Gold medal).21. DIPLOMA. Awarded to: I. Bostan, V. Dulgheru, V. Bostan, A. Sochirean, O. Ciobanu, R. Ciobanu, N.

Trifan for the “Floatable micro-hydropower station” . PRIZE ENVIRONMENT PROTECTION.„EUROINVENT’2009” - Iaşi, 9/05/2009.22. I. Bostan, V. Dulgheru, V. Bostan, A. Sochirean, O. Ciobanu, R. Ciobanu, Nicolae Trifan for the “Floatablemicro-hydropower station with adjustable blades”. „EUROINVENT’2009”.- Iaşi, 9/05/2009. (Gold medal).23. I. Bostan, I. Vişa, V. Dulgheru, V. Bostan, A. Sochireanu, O. Ciobanu, N. Trifan. Micro-hydropower stationfor the rivers water kinetic energy conversion” // - Cluj-Napoca, 2009 The International Salon of Researchand Innovations “PROINVENT’ 2009”. The DIPLOMA of EXCELLENCE and PROINVENT medal.24. I. Bostan, A.Greorghe, V. Dulgheru, V. Bostan, A. Sochireanu, V. Cartofeanu, O. Ciobanu, R. Ciobanu, I.Dicusar ă, N. Trifan. Flotable micro-hydropower station with self-oriented hydrodynamic blades” // - Cluj-Napoca, 2011 The International Salon of Research and Innovations “PROINVENT’ 2011”. The DIPLOMA ofEXCELLENCE and (Gold medal).



Authors Contact

Razvan Magureanu (POLI-B)[email protected]

Telephone: +40 722228514Fax: +40 214029342

Sergiu Ambrosi (POLI-B)[email protected]

Telephone: +40 721761481Fax: +40 214029342

Bogdan Popa (POLI-B)e-mail: [email protected]

Telephone: +40 214029189Fax: +40 214029189

Bostan Ion, Dulgheru Valeriu,Bostan Viorel, Sochirean Anatol (MOLD)

e-mail:[email protected]

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