In order to study the process of DC partial discharge（PD） in typical defects on XLPE cables

three typical model defects were fabricated by using operated cables. The PD characteristics of three cable defect models under DC voltages were studied by pulse current method. Four statistical spectra were extracted from Q–t and N–t. The results show that needle defects have the lowest PD initiation voltage

which is –7 kV. The Q–t pattern of void defects shows a "hill" shape and there is a "dead zone" in process of discharging. Many large-amplitude discharges occur in the initial stage of needle defect model

and then the discharge activity gradually disappears. The discharge of fracture defects is the most frequent. During the discharge process of fracture defects

the discharge magnitude increases gradually

and the discharge repetition rate increases first and then decreases. There is a correlation between the discharge magnitudes of the needle defect and fracture defect in adjacent discharges

while there is a correlation between the discharge magnitude q and Δt of the void defect and the needle defect. The most discharge magnitude of the void defect is less than the average discharge magnitude

and small amplitude discharge accounts for the majority in void defects. The partial discharge magnitude of the fracture is very dense and Δt has the smallest distribution range. The results provide basic experimental data and theoretical basis for the research of DC partial discharge in the XLPE cable.