Research And Design Of10kV Distributed Network Feeder Automation System’s Master Station

Research on10kV distributed network feeder automation system is very important to the urban and rural network reformation and the construction of smart distributed grid. The hardware, software and communication scheme of the feeder automation master station were designed. This article also do some research on one phase-to-ground fault line selection and fault section location algorithm, and interphase short circuit fault section algorithm for the system with distributed generation(DG).Firstly, the article showed the master station composition and function of each part. The hardware, software and communication scheme of the feeder automation master station were designed.Secondly, the article firstly analyzed the transient capacitance current(TCC) and the transient inductance current that produced when one phase-to-ground fault occurred in small current grounding system. The free oscillating component of the TCC is bigger in amplitude and can’t be disturbed by arc suppression coil, so it can be used to select fault line and locate fault section. The paper defined the free oscillating component of the TCC as transient zero-sequence current’s feature component(TZC’s FC). Secondly the paper analyzed the differences of the TZC’s FC in amplitude and polarity between normal and faulted line, and then proposed a method based on TZC’s FC to select fault line. Thirdly, the frequency and waveform of the TZC’s FC between normal and faulted sections were compared, and then proposed a algorithm based on the Appro Ximate Entropy of two adjacent FTU’s TAC’s FC to locate fault section. Lastly the algorithms were validated by simulation.Thirdly, the article showed that the traditional interphase short circuit fault section algorithm is no longer suitable for the system with DG. So a new method was proposed, and was validated by taking examples. The new method was based on matrix algorithm, but gave a forward direction to the network description matrix and fault current. The new method can locate not only the sections with two FTUs at each side, but also the sections at the end of feeders. The new method is simple, reliable, and has less demand to the rate of communication system.