AMI (advanced metering infrastructure) primarily consists of three parts: smart meter, communication network and meter data management system. Smart meter is the electronic meter equipped with the communication module, whose functions include the measurement of electricity consumption, recording the date and time at the contingency, and monitoring the abnormal voltage, current and power quality. It has the significant improvements of the reliability and quality in power grid, and creates the more value-added applications, like TOU (time-of-use),DR (demand response) and HEMS (home energy management system) in the future.