Research On The New Feeder Automation And Application In The Guang'an Distribution Network

Power supplying reliability is the important qualification of the best power enterprise. High reliability and high quality power-supply is the basic service the power enterprise offered. The distribution automation, as one of the important technique means which improve the reliability of the power supplying becomes more and more important . At present, the nation inputs a great deal of funds to build and rebuild the city electric power network, at the same , the distribution network automation project is also brought into the plan of the city network reform. The distribution network automation project has enlarged from experimentation to the application. The distribution feeders automation is one of the main function of distribution automation system. The author studies the feeder automation (FA) based system protection in this paper using the development of communication technique. The main works are as follows :1. In this paper, author expatiates protection theory of the bi-direction current differential protection of FA based system protection. Optical fibre communication making up of loop for signal exchanging . When fault happened, it judges the direction of fault current . If the direction of fault current is the positive direction, signal is not be sent, if negative direction , signal of forbidding action is sent out . The fault boundary is confirmed using 10ms handshaking signal ,so as to realize default isolation . After closing down fault ,if the line has electrical source only in one side ,some breakers will close to carry out system reconstruction.2. Based on the bi-directional current differential protection of the feeder automation of protection theory ,the author analyzes the process of feeder's protection action ,fault isolation, system reconstruction of chain model lines and T model lines in normal condition, breaker refusing action and lost communication.3. This paper proposes the requirements to optical communications of feeder automation, studies the compound optical fibre MODEM, analyses the data communication model and the realization way of optical MODEM. The scheme of FTU and its main functions is discussed, too.4. This scheme presented is successful through physical simulation experiment and has operated in a real distribution network of the Guang An city. They all proved the feeder automation is correct.The feeder automation has applied value to the distribution network which has communication channels.