Development Of Precise And Intelligent Three-phase Watt-hour Meter

With the swift development of electronic technology and communication technology, multi-rate, the new technologies and products come out unceasingly. Meanwhile, the watt-hour meter's technology also similarly turns toward multi-function, networking and the high accuracy measurement. In electric power measurement, the current transformer has a big error when it's working in low electric current load, for this problem, this paper present a project of watt-hour meter with the power partition measurement. In order to meet the intelligentizing request, the design of watt-hour meter is including telecommunication, Infrared copy the table and data inquiry.The design mainly takes high performance, low power loss MCU AT89C55 and high accuracy measurement chip ATT7022B as the core. The current signal sample measured by double voltage-ratio current transformer, and combined with the real-time power to relize the power partition measurement. The measurement circuit and software flow are designed after full analysis and research on measurement principle. And more others circuit designs including power module, connection module, display module and time module are achieved.To combine with hardware design, this paper first makes the overall construction systematically to the software part. In order to reduce redundant program and improve the readability and maintainability, the design of software adopts modularization program. The article has analyzed system's principle of work and main outline of the software programming through the flow chart. After program and debugging, more intelligizing functions have come true, and made the watt-hour meter perfectly.At present, this meter has relized precision balance in full range and accurate measurement. And all data are proved to be actual and effective by experiment results.