A method for identifying the fault current of DC traction power supply system based on EMD approximate entropy

In this paper, an identification method of the oscillation current and the short-circuit fault current in DC traction power supply system based on empirical mode decomposition (EMD) and approximate entropy is proposed. The feeder current is decomposed by means of EMD technique, and the sum of the approximate entropy of each intrinsic mode function (IMF) is calculated. Thus, the characteristic value that reflects the running status information of DC traction network is obtained. According to the computed result, it can be found out that the feature extraction method combined EMD and approximate entropy can effectively distinguish the oscillation current and the short-circuit fault current of DC traction power supply system.