A study on streamer discharge characteristics along contamination insulator surface

During the pollution flashover process, streamer discharge is a very important stage before arc formed. In the paper measured the streamer propagates between two parallel plane electrodes by using three-electrode structure, and compared the characteristics of propagation while contamination with different ESDD and NSDD was brushed on the insulator surface, and simulated the distribution of electric field on insulator surface before and after the contamination was brushed by using Ansoft analysis software. The results showed that: the ESDD(or NSDD) increases, Eth increases first, then remain unchanged. After the applied field is greater than Eth, velocity of different ESDD and NSDD is similar. Through simulation found that the presence of contamination distorts the electric field distribution on insulator surface. The electric field of contamination area was obvious reduced and enhanced on both ends of the area. The change in conductivity of contamination makes the electric field distribution changes, and then causes the differences of the waveforms and field required for stable propagation of streamer.