Prepaid Energy Meter Using Pic Microcontroller
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Transcript of Prepaid Energy Meter Using Pic Microcontroller
PREPAID ENERGY METER USING PIC MICROCONTROLLER
INTRODUCTION• The scope of the project work is to introduce advanced
technology in converting dc voltage in to ac voltage and introducing prepaid energy metering concept.
• The energy meter used in this project work produces pulses according to the load and this meter is converted as prepaid energy meter using smart card, hence this meter can be called smart energy meter.
• This kind of smart energy meters also can be installed at each and every house, where the state electricity department going to supply the conventional energy. Now a days energy Measurement and electric energy pilferage detection has become prime importance for the state electricity department.
INTRODUCTION
• With the help of this project work lot of Manpower can be reduced and power pilferage can be controlled.
• The overall system can be called as AMR (Automatic Meter reading) system, the main advantage of AMR system is that the consumed energy price can be calculated and at the same time price (amount in rupees) can be displayed automatically.
• Finally the simplest form of smart metering is a display meter, which allows consumers to monitor consumption in money terms rather than kWh.
Outlook• Monitor Unit of Split Meter
LCD
Button
IC card socket
CIRCUIT DIAGRAM
RA0/AN02
RA1/AN13
RA2/AN2/VREF-/CVREF4
RA4/T0CKI/C1OUT6
RA5/AN4/SS/C2OUT7
RE0/AN5/RD8
RE1/AN6/WR9
RE2/AN7/CS10
OSC1/CLKIN13
OSC2/CLKOUT14
RC1/T1OSI/CCP2 16
RC2/CCP1 17
RC3/SCK/SCL 18
RD0/PSP0 19
RD1/PSP1 20
RB7/PGD 40RB6/PGC 39
RB5 38RB4 37
RB3/PGM 36RB2 35RB1 34
RB0/INT 33
RD7/PSP7 30RD6/PSP6 29RD5/PSP5 28RD4/PSP4 27RD3/PSP3 22RD2/PSP2 21
RC7/RX/DT 26RC6/TX/CK 25
RC5/SDO 24RC4/SDI/SDA 23
RA3/AN3/VREF+5
RC0/T1OSO/T1CKI 15
MCLR/Vpp/THV1
U1
PIC16F877A
D7
14D
613
D5
12D
411
D3
10D
29
D1
8D
07
E6
RW
5R
S4
VSS
1
VD
D2
VEE
3
LCD1LM016L
RV1(2)
51%
RV1
1k
X1
CRYSTAL
C122p
C222p
R1(1) R1
10k
C310u
D1
LED-BIRG
D2
LED-BIRG
OUT IR
T1IN11
R1OUT12
T2IN10
R2OUT9
T1OUT 14
R1IN 13
T2OUT 7
R2IN 8
C2+
4
C2-
5
C1+
1
C1-
3
VS+ 2
VS- 6
U2
MAX232
C4
1u
C5
1u
C6
1u
C7
1u
C7(-)
from RF reader
TO reader
A11
A22
A33
A44
A55
D66
D77
D89
D910
TE14
DOUT 15
RS 11
CTC 12
RTC 13
U3
M145026
to RF transmitter
CIRCUIT DIAGRAM
RA0/AN02
RA1/AN13
RA2/AN2/VREF-/CVREF4
RA4/T0CKI/C1OUT6
RA5/AN4/SS/C2OUT7
RE0/AN5/RD8
RE1/AN6/WR9
RE2/AN7/CS10
OSC1/CLKIN13
OSC2/CLKOUT14
RC1/T1OSI/CCP216
RC2/CCP117
RC3/SCK/SCL18
RD0/PSP019
RD1/PSP120
RB7/PGD40
RB6/PGC39
RB538
RB437
RB3/PGM36
RB235
RB134
RB0/INT33
RD7/PSP730
RD6/PSP629
RD5/PSP528
RD4/PSP427
RD3/PSP322
RD2/PSP221
RC7/RX/DT26
RC6/TX/CK25
RC5/SDO24
RC4/SDI/SDA23
RA3/AN3/VREF+5
RC0/T1OSO/T1CKI15
MCLR/Vpp/THV1
U1
PIC16F877A
D7
14D
613
D5
12D
411
D3
10D
29
D1
8D
07
E6
RW
5R
S4
VS
S1
VD
D2
VE
E3
LCD1LM016L
RV1(2)
51%
RV1
1k
X1
CRYSTAL
C122p
C222p
R1(1) R1
10k
C310u
FROM RF transmitterA11
A22
A33
A44
A55
D615
D714
D813
D912
VT11
R2/C210
C17
R16
DIN9
U2
M145027
BLOCK DIAGRAM
PIC16F877A
CARD READER UNIT
GSM
POWER SUPPLY
RF RECEIVER
LCD DISPLAY
LOAD
BLOCK DIAGRAM EXPLANATION• In this system the user has to purchase an EEPROM based recharge
card and it should be inserted in the slot provided on prepaid energy meter kit. After inserting the recharge card into the system, Then the system will be loaded with specific units as per the recharge card value. A 16X2 LCD is provided to read units available. Here the system is connected with three to four loads. If the load increases in the system, current also increases and is calculated by an ADC and its corresponding count is also calculated. Whenever the count value reaches one thousand, 1unit is decremented from EEPROM and these values are displayed on LCD.
• An EEPROM is provided on the board to store the updated recharge units and energy meter pulse count. At every instant the count value and units values are stored in EPROM so that the data will not be lost even in power failure cases. When 1 unit is decremented from EEPROM the system will give a beep sound. If recharge value below 10 units the GSM modem send alert message to owner .When the recharged units become zero on power consumption, the system shutdown all the loads connected to it by giving a continuous beep sound.
Hardware Components
• Power supply[5v]• PIC16F877A microcontroller• GSM modem• Current Transformer• Voltage Transformer• Max232 – serial communication
Power Supply Circuit
V D D
V D D
C 70 . 1 u F
J P 2
2 2 0 V A C
12
- +
D 1
14
32
U 27 8 0 5
1
3
2V I N
GND
V O U T
C 61 0 0 u F
C 54 7 0 u F
R 42 2 0 o h m
D 2
L E D
Power Supply – Circuit Description
• The operation of power supply circuits built using filters, rectifiers, and then voltage regulators. Starting with an AC voltage, a steady DC voltage is obtained by rectifying the AC voltage, Then filtering to a DC level, and finally, regulating to obtain a desired fixed DC voltage. The regulation is usually obtained from an IC voltage regulator Unit, which takes a DC voltage and provides a somewhat lower DC voltage, Which remains the same even if the input DC voltage varies, or the output Load connected to the DC voltage changes.
About Microcontroller
• PIC16F877A microcontroller is used for this project
• It is 8-bit Microcontroller• System is RISC Architecture• It has Small set of Instruction set• It has 35-Instructions only• Compatibility: avail 28/40 Pin ICs
Microcontroller overview
• Operating Speed Max 20 MHz, Voltage-(2-5.5)v
• Memory: Flash Program 8Kx14 Words, RAM 368 Bytes, EEPROM Data Memory 256 Bytes
• Low power, High speed Flash/EEPROM Technology
Features of Microcontroller
• It has 5 Ports for Internal and External usage• It has on chip Timers. 3 Timers are avail• It has in built Analog to Digital Converter• In built Multiplexer availability for signal
Selection• It has serial as well as Parallel Communication
facilities• In built Capture, Compare and Pulse width
modulation
UART pins inPIC16f877A
• The UART always transmits data on pin RC6/TX• The UART always receives data on pin RC7/RX• The RS-232 standard defines lots of other
signals other than TX and RX used for handshaking.
Voltages
• The UART input/output uses 0V for logic 0 and 5V for logic 1.
• The RS-232 standard (and the COM port) use +12V for logic 0 and –12V for logic 1.
• To convert between these voltages levels we need an additional integrated circuit (such as Maxim’s MAX232).
MAX232
V D D
R X
TX T2 O U T
R 2 I N
U 1M A X2 3 2
1 38
1 11 0
1345
26
1 291 47
1615
R 1 I NR 2 I NT1 I NT2 I N
C +C 1 -C 2 +C 2 -
V+
V -
R 1 O U TR 2 O U TT1 O U TT2 O U T
VC
CG
ND
C 1 1 0 u F
C 41 0 u F
C 31 0 u F
C 21 0 u F
GSM modem• A GSM modem is a wireless modem that works with a
GSM wireless network. • A wireless modem behaves like a dial-up modem. The
main difference between them is that a dial-up modem sends and receives data through a fixed telephone line while a wireless modem sends and receives data through radio waves.
• A GSM modem can be an external device or a PC Card / PCMCIA Card. Typically, an external GSM modem is connected to a computer through a serial cable or a USB cable.
• Like a GSM mobile phone, a GSM modem requires a SIM card from a wireless carrier in order to operate.
AT COMMANDS
• computers use AT commands to control modems. Both GSM modems and dial-up modems support a common set of standard AT commands.
• GSM modems support an extended set of AT commands.
Operations
• Reading, writing and deleting SMS messages.• Sending SMS messages.• Monitoring the signal strength.• Monitoring the charging status and charge
level of the battery.• Reading, writing and searching phone book
entries.
GSM phone or modem supports SMS text mode
Check if your GSM phone or modem supports SMS text mode
To check if your modem supports this text mode, you can try the following command:
AT+CMGF=1 <ENTER>
If the modem responds with "OK" this mode is supported.
Software Tools
• MPLAB IDE• Hitech c compiler• Win pic programmer• ORCAD design
MPLAB IDE
Winpic800 Programmer
Prepaid meters advantages• High accuracy over a wide current dynamic range• Reliability and robustness• Flexibility of design• Automatic Meter Reading (AMR)• More easily enable new functionalities• Multi tariff billing• Tamper proofing• Prepayment meters• Power out range detection• Power factor detection• Easily reconfiguration, upgrade • Do not use gears that wear out or magnets that saturate with DC
current• Do not require precision mechanics or have large tolerance variations
over temperature
• Pay before use• Keep customers on supply• Recover money owed (debt)• Lower Overheads• No bill production• No bill distribution• No need to chase payments• No further actions such as disconnections
Why Prepayment – EnergySupplier?
Why Prepayment – EnergySupplier?
• Social Acceptability• Customer responsible for Disconnection• Load and Demand Side Management• Limit load• Load based• Time based
Why Prepayment – The Customer?
• >80% Mobile phones used in India are prepaid• Flexible Payment Solution• Pay to suit your income status• Daily, Weekly , Monthly Budgeting• Show true cost of consumption and money Left• Reduce consumption when income is tight– make money last• Reduce waste – conserve energy
• No Bills• No hidden surprises• No having to find the money• No billing errors• No socially unacceptable• disconnections
Why Prepayment – The Customer?
CONCLUSIONS
• Advanced electricity meters that generate consumption data enabling customers to see when they are using energy, to manage that use more efficiently
• To save money by adjusting energy use in response to price signals.
• To save money, the consumed energy corresponding price is displayed for the consumer benefits.
• This project work has been taken up which serves the purpose of energy monitoring and controlling by implementing prepaid system.
• It is hoped that this work helps the electrical engineers for better energy management and its utility in the distribution system for economic liability of the electrical companies.
THANK YOU