Multi-source separation method for partial discharge detection in substations

Partial discharge monitoring and location system at substation receives radio frequency (RF) signals emitted by partial discharge to position partial discharge using a set of omni-directional RF antenna array. As it is possible for the entire substation to have several partial discharge sources simultaneously, the basic requirement of partial discharge detection at the substation is to judge whether there are multi-source partial discharge signals, and then identify and isolate them. Based on different time domain and frequency characteristics of ultrahigh frequency (UHF) partial discharge signals generated by different partial discharge sources, we perform time-frequency analysis and fuzzy clustering over RF pulse waveforms generated by partial discharge which are continuously acquired and stored, and isolate partial discharge signals from different partial discharge sources or interferences. By this method, we can effectively isolate and accurately position multiple partial discharge sources. Our study lays the foundation for identification of partial discharge types. The feasibility of this method has been proved by field test.