Single-phase ground fault location method based on REMD-SD

When a single-phase ground fault occurs in a 10kV small-current neutral ungrounded system, the fault current signal is very weak, which makes it difficult to locate the fault after the fault indicator transmits the fault current information to the main station. To solve the above problems, this paper proposes a ground fault location method based on the combination of Robust Empirical Mode Decomposition (REMD) and second-order difference sequences for fault indicators. Firstly, the transient zero-sequence currents of one fifth cycles before and after the fault occurrence time are decomposed by REMD to extract the Intrinsic Mode Functions (IMF) of the first section, and then the second-order difference sequence algorithm is used to obtain the initial concavity and convexity of the fault, and then the fault section localization is carried out according to the difference of the concavity and convexity. The simulation results show that the method has good reliability.