The partial discharge characteristics study of insulated copper bus bar

This paper sets three typical partial discharge defect models at the joint of an insulated copper bus bar, containing floating voltage discharging model, corona discharging model and insulation damage model. We applied high voltage to the insulated copper bus bar and measured the partial discharge of each model separately, using the pulse current method, UHF method, ultrasonic method, infrared imaging method and ultraviolet imaging method. Then we recorded the partial discharging characteristic quantities, including discharging amplitude, discharging times per second and PRPD (phase resolved partial discharge) spectrum. Basing on the experiment data, we got the distribution of each characteristic quantity with the applied voltage. Furthermore, we analysis the distribution similarities and differences of the three defect models. The results show that the pulse current method and non-contact ultrasonic method are more effective for floating voltage discharging defect and corona discharging defect. And for the kind of insulation damage defect, only infrared imaging method is effective. It can be concluded that pulse current method and infrared imaging method should be both adopted when we conduct on-site partial discharge measurement for insulated copper bus bar.