Calculation of lightning trip-out rates for 10 kV overhead distribution line

The insulation level of 10 kV overhead distribution line is relatively low with high flashover rate. This paper analyzes the lightning performance of direct lightning by using ATP-EMTP. Basing on EGM model, attract range and lightning trip-out rates of direct lightning is calculated. The coupling model proposed by Agrawal and finite difference time domain (FDTD) method were used to calculate the indirect lightning overvoltage due to the nearby lightning. Meanwhile, the lightning trip-out rates of induced was also calculated by interval statistical method. The numerical method was verified by comparing with a reference. The simulation calculating results showed that indirect lightning trip-out rates take up more than 80 percent of the total lightning fault.