Research on Discharge Characteristics of Potential Transfer for Live Working on UHVDC Transmission Line

To investigate discharge characteristics of potential transfer process for live working on ultra high voltage direct current (UHVDC) transmission line, the streamer discharge model of potential transfer is built based on the theory of hydrodynamics. The discharge model considered particle generation, motion and dissipation process caused by strong electric field. This paper analyzed the time variation of electric field and streamer developing speed, calculated discharge current and transient energy of different transfer distances. The results show that with the increase of the discharge time, the electric field intensity of the head of streamer decreases during the process of discharge of potential transfer and the speed of the streamer propagation increases. The discharge current between the potential transfer rod and the conductor increase as the potential transfer distance decreases. The optimum potential transfer distance is about 0.45m for live working on +/- 800 kV transmission line; The transfer transient energy under different transfer distances is around 1.0J, and the transfer energy increases with the increase of transfer distance. When the transfer energy is higher than 1.0J, the conductive gloves may have ablated. Thus, for protecting the operating personnel, a potential transfer rod should require during potential transfer process of live working on the +/- 800kV transmission line.