Design Of An Smart Electricity Metering Module Based On STM32and ATT7022E

In the next five years, with the construction progress of national smart grid, smart meters in the user side will be in great demand on the number of170million, in an conservative estimation. Before2015,State grid is expected to creat a complete power-expenditure information collection system, and residential electricity consumption information will be in wide applications, and household numbers will be more than140million, and smart meters will occupy more than80%of all electricity meters and it will be up to100%by2020.This topic’s main goal is to design an smart electricity metering module based on STM32and ATT7022E, this metering module has most function of smart three-phase meter, which can measure and storage voltage, current, power, power factor, angle and harmonic parameters. Micro controller STM32is the product of the Stmicroelectronics Company, and its use of Cortex-M3kernel is a new version of ARM,the characteristics of this kind new kernel is the power consumption small and has good performance. This module will give priority to master station(PC or power load management terminal) provide a lot of power data, in addition to real-time data, and historical data.The smart electricity metering module includes hardware and software,my main work is writing and debugging software. And software is divided into two layers, respectively is hardware interface layer and the business layer. I work more focused on the writing and debugging software of the hardware interface layer.The micro controller of this module just read ATT7022E metering results through the SPI interface,because ATT7022E’ metering precision is very high,and it play a major role of the whole module in the precision aspects,so the metering precision of this module is high,meet the design requirements. The metering error of active power is less than0.5%, and the metering error of reactive power is less than2%.