In order to judge the internal insulation status of cable accessories in time and accurately, to avoid the cable breakdown and cause a major accident, this paper studies the partial discharge of XLPE power cables. The discharge characteristics of three kinds of XLPE power cables are simulated in the laboratory environment. Three kinds of defective partial discharge characteristics of XLPE power cables are studied by ultrasonic inspection system. The ultrasonic signals of different defects are analyzed.The characteristics of the time domain and the phase spectrum of the signal are studied. The relationship between the voltage and the maximum discharge amplitude, the average discharge amplitude and the number of discharges is studied, and the typical discharge spectrum is drawn. The same defect type is stable and reproducible under the same conditions. The discharge process of different defect types is different, and the partial discharge spectrum, single pulse waveform and PRPD spectrum are obvious. It is of great significance to prevent the occurrence of cable accidents and to ensure the safe and stable operation of power system.

XLPE; defect simulation; partial discharge; PRPD spectrum; pulse waveform