A Method for Separating Mixed PD Signals Caused by Multiple Insulation Defects in GIS

摘要

When there are two partial discharge (PD) source signals in the gas insulated switchgear (GIS), mixed PD signals will be generated, which will interfere the judgment and location of PD signals. In order to separate the mixed PD signals, a blind source separation (BSS) algorithm based on maximizing the fourth-order cumulant is designed, and the particle swarm optimization (PSO) algorithm is used as the optimization function. Finally, the performance of the algorithm is tested, and the waveform similarity coefficient is used to evaluate the separation effect of the algorithm. Simulation results show that the proposed method can effectively separate the mixed signals whose difference in trigger time is greater than 2ns, and the similarity coefficient reaches more than 0.95. This method lays a foundation for the subsequent work of GIS fault identification.