Calculation Of Lightning-Induced Voltages For Power Distribution Lines

The lightning-induced overvoltage is the main reason for the failure of the low voltage (LV) distribution lines. In order to simulate of lightning-induced overvoltage, this paper calculates the space electromagnetic field generated by the lightning based on the existing channel-base current and lightning return stroke current models; then using the Agrawal field-to-line coupling model the overvoltage caused by lightning strikes near the distribution line is calculated by the finite difference-time domain (FDTD) method. The influence of ground loss is considered by the method of Cooray-Rubinstein formula and vector fitting. The correctness of the algorithm is verified by the literature result. Based on this algorithm, the characteristics of the induced overvoltage on the transmission line and the influence of the insulator, the lightning current waveform, the position of the lightning strike point and the ground conductivity, to the induced overvoltage is analyzed.