Design Of Single-phase Prepayment Meter Based On RFID+STS

The problem of electricity fee retrieving is an obstacle holding back the development of Chinese electricity provider. The prepayment meter adopts a kind of marking mode,"Buy first, Use later", which indicates electrical energy is commodity. The research purpose is to realize the accurate measuring of energy, build the communication ties between customers and the electricity management, implement the prepayment function based on RFID and provide reliable evidence for scientific management on energy.The principle of the meter was introduced, and a method of energy sale management that intergrades RFID and IEC62055-41 standard transfer specification was developed. The method makes full use of the advantages that radio frequency card is passivity, connectless. It will guide the inhabitant's electricity management toward automation from the artificial metering work and IC card management, and solves the existing problem that there are too many prepayment protocols to be followed.This thesis consists of 7 chapters. The first chapter introduced the development course of energy meter, analysed several existent prepayment energy management systems, and discussed the structure and principle of the RFID system. The second chapter described the function, structure, process, and development/operation environment of the single-phase prepayment meter based on RFID+STS. The third chapter gave the structure and principle of ADE7755, discussed the characteristic of MSP430F147, and designed the measurement part and information-processing part hardware. The fourth chapter gave the hardware and flowchart of the radio frequency interface. The fifth chapter introduced the framework of wireless communication network, Hardware and software design of communication interface circuit, studied the IEC62056-21, STS, and mathematical principle of 3DES in detail. The sixth chapter analyzed meter's errors and corresponding solution, discussed anti-disturbance, low-power and information-safty design to improve reliability of the prepayment meter. Finally, the deficiencies of the thesis were summarized, and the improvement methods were proposed.The production practices shows that the radio frequency card reads and writes stably, has strong ability of anti-interference, delivers data credibly, and the management is real-time and convenience.