Study on the Discharge Characteristics of Combined Air Gap with Floating Potential Conductor under DC High Voltage

In order to study the discharge characteristics of combined air gap with floating potential conductor, the rod-rod-plate is selected as a research model. The characteristics of the corona discharge and the breakdown discharge were studied in this paper. Experiment shows that when the floating potential conductor is close to the high voltage electrode or the ground electrode, the shorter air gap will be bridged by local arc. Meanwhile, the breakdown voltage appears local minimum value. And then the main discharge occurs. When the floating potential conductor is located in the middle of the air gap, the corona discharge phenomenon is not obvious. At the same time, the breakdown voltage reaches a maximum value, and the two air gaps break down almost simultaneously. The results of COMSOL simulation show that the electric field distortion caused by floating potential conductor is the major reason for the discharge process of combined air gap. During the experiment, the relationship between the spatial position and the corona onset voltage and the breakdown voltage were studied. The experiment and simulation results will help us to understand the discharge characteristics of combined air gap with floating potential conductor.