The Design Of Multi-function Electronic Watt-Hour Meter Based On Communication Protocol IEC62056-21

Electric power becomes more and more important energy with the rapid development of economy. The wide application of electric power has greatly expedited the accuracy, operational flexibility and intellectualization of electronic watt-hour meter.Electronic multifunctional watt-hour meter is an integrated system including hardware, software and crust. The design and production of a meter must follow the related national and industry standards. Firstly, the definition, the classification method of electronic watt-hour meter, and the rules which must be conformed are introduced. Secondly, the IEC62056 series standard used for watt-hour meter communication, particularly IEC62056-21, IEC62056-61 and IEC62056-62, are introduced. The hardware design of the meter includes the analysis of each function unit, the circuit design of power and logic units and the application principle of primary devices. The EMC (Electromagnetic Compatibility) design scheme and its practice are also described. The software design includes initialization, the electric power calculating, the even registering, communication and so on. The importance of software is application of IEC62056-21, IEC62056-61 and IEC62056-62 for communication.The tests and field running prove that the accuracy of designed watt-hour metering reaches class 0.5s, various functions such as multiple rate active power and reactive power energy measurement, event record, data backup, infrared and RS-485 communication, display and so on are correctly implemented. Especially, a new communication standard IEC62056-21 is used here. The IEC62056 communication is not only fit for a simply civilian meter, but also fit for an important client's complex measuring/inspecting apparatus and the data gathering/management system. It has been commonly used abroad. IEC62056 can transfer data through the ordinary communication medium, such as RS-485 or infrared, etc. It has great compatibility, flexible portability and good ability of structure network.The experiment proves the feasibility of IEC62056-21 for meter communication. Because the meters use the international uniform format for internal data memory according to IEC62056-61, the mutual compatibility between measurement apparatuses and the manage convenience are greatly improved. This communication method is worth of attention and to widely popularized.