Development Of 400V Feeder Line With Automatic Switch Unit Of Distribution Automation System

A new Low Voltage Distribution Integrated Automation System based on CAN (Controller Area Network) communication networking is proposed in this paper. And the distributed protection and monitoring unit is researched and developed. This unit is particularly designed for monitoring 400V feeder with backup automatic switch. It could accurately measure and calculate: voltage, current, frequency, active power, reactive power, power factor and energy. When bus gets into trouble, it can perform the function of automatic switching to backup power supply. That this unit offers both RS-485 and CAN bus communication mode makes it more flexible and applicable.This paper improves on traditional half-wave measurement circuit. A new full-wave measurement circuit structure is put forward that would increase distribution automation system reliability and veracity.The distributed protection and monitoring unit in this paper can instead of general instruments of low voltage distribution system. It not only combines ampere meter, voltage meter, active power meter, reactive power meter and power meter, frequency meter into a meter, but also increases monitoring position switch, control bus switching alternately and monitoring energy. That makes low voltage distribution system instrument design, install and debug simply. Communication technologies used satisfy it all kinds of local functions which low voltage distribution automation system needs, at the same time, as a RTU unit of dispatch automation.