Location Method Based On Fuzzy Entropy For Single Phase To Ground Faults In Non-Effectively Grounded Distribution Network

Single phase to ground faults in non-effectively grounded distribution network is difficult to locate accurately, because of small fault current and noise influence. This paper proposes a location method based on the fuzzy entropy of transient zero-sequence current in the first capacitive frequency band. Firstly, the impedance characteristics of zero-sequence network are given, and the calculation method of the first capacitive frequency band is analyzed. Then, based on the simplified equivalent network, the difference of transient zero-sequence current characteristics between upstream and downstream of the fault point is summarized. Subsequently, the definition and calculation method of fuzzy entropy are given, and a location method by comparing the fuzzy entropy of transient zero-sequence currents is proposed. This method is applicable to both ungrounded and resonant grounded systems, and is capable of detecting high impedance faults. Finally, the feasibility and effectiveness of proposed method are verified by PSCAD simulation.