The Design And Development Of Three-phase Prepayment Watt-hour Meter Based On RFID

The problem of meter reading and electricity fee retrieving is an obstacle holding back the development of Chinese electricity provider. The management adopts prepayment watt-hour meter which is a popular kind of marking mode:"Buy first, Use later". But the contact-type IC card exists contact's deformation and rust problem. The research is to design three-phase prepayment watt-hour meter based on RFID technology, which can solve these problems effectively. This meter can be used for "one meter and one card",or for "one card and multi-meter" and "one meter and multi-card".Firstly,after researching the current situation and the development trend of the Watt-hour meter, this paper points out the function limitation of traditional mechanical meter and Logic Security card or CPU card prepayment meter, which is widespread used at present. This paper analyzes the development and application of the RFID technology, and then expatiates the excellence of watt-hour meter based on RFID technology.Secondly,sets forth the principle of RFID system, and gives the classification of RFID card in accordance with the different ways. After making some contrast between the Type A card and Type B card in RFID standards ISO14443 that used wide, expatiates the structure principle and anticollision method of Mifare MF1 S50 RFID card that adopted in this design.Thirdly, brings forward the specific design requirements of this subject, elaborates the overall hardware design proposal, and then expatiates the design of FM2306A control module, ATT7030A three-phase electrical energy measuring module, FM1702SL RFID card read-write module, infrared and 485 communication module, relay control module and power circuit module in the RFID card meter.Has discussed the principle and implement method of each module circuit in detail, designed the schematic diagram and completed the printed circuit board design, and list some issues that need to pay attention to in hardware design,summes up the anti-jamming methods.Fourthly, the overall software design idea is described. According to the hardware principle, the bottom procedure of the system is designed. The realization methods for data structure module, initialization module, communication operation module, RFID card operation module are discoursed in detail, the flow chart and code realization are given.Fifthly, combines with the international and domestic standards, the error adjustment of the watt-hour meter is made.Measurement & communication function, EMC performance are also tested strictly. In the end, reasons for errors are analyzed, and countermeasures against them are given.The actual run result indicates the Three-phase Prepayment Watt-hour Meter Based on RFID technology can achieve the functions such as energy metering, RFID card prepayment, infrared & 485 communication steadily. The system has strong anti-jamming ability, and all parameters reach the expected designed require.