The Design And Realization Of Prepaid Three-Phase Power Meter Based On CPU Card

With the continuous development of society and the continuous increase of social service awareness, it's an inevitable trend to become network and intelligence for social service charge. As a product of this era, IC card prepaid power meter meet the electric power industry's ever-increasing demands which about energy's measurement, control and management from the technical. IC card prepaid power meter as a novel tool for energy metering and charging is increasingly being welcomed by the electric power sector. At present, the IC card prepaid power meter mainly use logic encryption card and CPU card, in the three-phase prepaid power meter design, CPU card with its high security, high reliability, is increasingly favored by power companies.At first, this paper summarizes the present development status and the development prospect of IC card prepaid power meter, and the IC card technology and its applications. The three-phase CPU card power meter's technical condition is being introduced. And then, this three-phase CPU card power meter's hardware design program is being introduced; In accordance with the functions of the hardware, this circuit modules, including power supply unit, metering unit, MCU control unit, display unit, communications unit , IC card unit are being designed; following, the hardware system's anti-interference measures is described in detail.This paper focuses on a three-phase prepaid power meter's program design and implementation which based on CPU card and security module ESAM. COS is introduced and the system's data security is analyzed. Then, arm at the power meter's characteristic, it designed the system's security system, and defined the type of card and the application process, and designed the structure of the card. Finally, this power meter's software implementation means are introduced, the overall achievement of the software process and the software design concepts are expounded, the CPU card's prepaid processing module is introduced on detail. System has been designed to take full account of the general nature, the model can increase or shield some of the features through the control word, so it can to meet the requirements of different customers which not change code.In the use of the prepaid power meter, the user card is held by the user, and it is not controllable by the power companies, so the CPU card's data security becomes more important, which as the carrier of the transmission of information. CPU Card is not only a carrier of electricity, but also can change parameters, can achieve various management functions of power meter, can simplify the application process.The performance test in practice shows that, this three-phase prepaid power meter based on CPU card run stability, anti-interference ability, read and write CPU card's data in real-time reliable, the application process is flexible, safe and reasonable.