Effects of Impulse Voltage Waveforms on Lightning Shielding Simulation Test of Transmission Lines

In order to make a research on the effects of impulse voltage waveforms on lightning shielding property of transmission lines, this paper adopted the model of 500 kV transmission lines in plain country at the ratio of 1:40. Large amount of impulsive discharge tests were done, including lightning surge voltage and switching impulse voltage. The scattergram of shielding failure probability of lightning stroke points in space is plotted, and the distribution rule is in close agreement with the results calculated by EGM model. The shielding failure probability is calculated by two methods according to the simulation test results, and the results are compared with the results calculated by order method and LPM method. Comparative result shows that test with switching impulse voltage is closer to the reality than test with lightning surge voltage when the length of the air gap is the same.