Research On Three Phase Electronic Multifunction Energy Meter

With the promotion of energy measurement automation and the popularity of large customers meter reading, as well as the full implementation of the policy about energy prices relating to the rate periods and billing, the demand of three phase electronic multifunction watt-hour meter is growing rapidly. According to this application of the electricity market demand as well as the characteristics of multifunction energy meter at home and abroad at present, strictly referring to the relevant national standards, a high precision, stable performance, strong anti-jamming ability multifunction meter was developed. It is in line with the new generation of power industry communication protocol DL/T645-2007: multi-function watt-hour meter communication protocol.At first, the paper introduced the development process of the energy meter and its application status, as well as its technological development trend. Then two of the current popular multi-function watt-hour meter design schemes were compared. After considering the performance and costs, the system's design program was determined. It is a collaborative design using special energy metering IC ATT7022B plus MCU ATmega128. Energy metering IC provides various parameters of system functionality needed and MCU is responsible for parameter processing, displaying and storage.In accordance with the function of the system, hardware circuit was divided into power supply unit, energy acquisition unit, control unit, storage unit, real time clock unit, load control unit and communication unit, etc. This focused on the design of the power circuit and RS-485 lightning protection circuit. Combination of hardware circuit design, the paper makes overall software architecture. In order to enhance the readability and maintainability of software system, the design of software adopts modularization programming. Through the flow chart, the article has a brief analysis of the working principle and the main points of software programming. After software programming and debugging, the energy meter has achieved its function ultimately, which include active and reactive energy measurement time,demand metering, key display, anomaly monitor, events record, query and other functions.At last, the reliability of electronic energy meter has been designed and researched. Counter electromagnetic interference measures have been taken both in hardware and in to ensure that the system can work in the field environment stable.The three phase electronic multifunction energy meter developed by the subject is basically to meet the design requirements of the system in functionality and performance, and in a lab environment testing there have been no accidental crash, key responding too slowly, or display garbled and so on.