Design And Research On Electronic Pre-Payment IC Card Three-Phase Watt-Hour Meter

The Pre-payment technique is a new research domain in our country,which is used to resolve the problem of charging in public terrain(especially in the district of flowing population).Pre-payment has come into being production and give birth to a new industry.The Pre-payment watt-hour meter could change the charging manner to voluntary charging instead of inquire charging,also prevent the heavy work of power supply department.The Pre-payment watt-hour meter is under the control of MCU and could lighten the workload of the power supply manager.The use of Pre-payment watt-hour meter will settle the charging problem which has puzzled the power supply department for a long time.The Pre-payment watt-hour meter has many data-transmission medium and the IC card is the most popular one.IC card has many advantages such as facility in reading and writing,high dependability, high security and facility in intelligent control.The use of Pre-payment IC card watt-hour meter will bring considerable community benefit and economy benefit.The common digital measurement arithmetics of power system which consists of AC sampling and frequency measurement are discussed at first.Then introduce the contact IC card and serial communication of MCU because of their use in this design. The detail design of electronic Pre-payment IC card three-phase watt-hour meter is focal point of this paper.The core of electronic Pre-payment IC card three-phase watt-hour meter is energy metering IC ATT7022A and microcontroller unit ATmega64.IC Card acts as data-transmission medium of watt-hour meter and power supply department.The watt-hour meter utilizes magnetic latching relay to switch off the power supply.The hardware and software designing of watt-hour meter system is expounded.The paper also illustrates the selecting of the main ICs and provides the interface circuit of each part. The software of each functional module is programmed in C language and the flow chart of software is also presented.The watt-hour meter will be interfered by the environment when it is working,so it requires a strong anti-interference ability.The last chapter introduced the anti-interference technique and common means to enhance anti-interference of microcontroller system,then presented the application of these methods in the design of electronic Pre-payment IC card three-phase watt-hour meter.