Detection method of partial discharge in XLPE Cable accessories based on the method of VHF combined with acoustic emission

Based on the experiment carried out in the lab on several cable accessories in which there are some typical PD models(In this paper, they are the models of protrusion discharge and floating discharge), the method of VHF Combined with acoustic emission (AE) for detecting PD in the XLPE cable accessories was introduced. The time domain characters of the AE and VHF signals are researched and compared in order to distinguish the PD signal from the disturbance. Two kinds PD spectrum of Qmax-phi and N-phi were analyzed and contrasted between the VHF and acoustic emission PD signals, which are protrusion discharge and floating discharge. The way to locate the PD point was also introduced. The results of the research had proved that the reliability of the PD detection is improved using the combined method.