Statistical Study of Needle-plate Partial Discharge Stage Characteristics under DC Voltage

The characteristics of needle-plate corona partial discharge (PD) under direct current (DC) voltage are studied based on the statistical method. Apply step-up positive and negative DC voltage on the needle-plate model to acquire PD signals. Then PD pulse repetition rate (n), amplitude (V), interval time (Δ t) and derivative parameters are extracted, and the statistical rules of these parameters in each stages are concluded. Discharge characteristics of different discharge stages are analyzed, and positive and negative coronas are compared. The study helps to understand the development process and the mechanism of PD.