Corona on multiconductor overhead lines illuminated by LEMP

Two corona models, applicable to the calculation of lightning-induced overvoltages in multiconductor overhead lines, are considered in this paper. The first model represents corona by an increase in each conductor self capacitance after the voltage has reached a threshold value, and in the second model, the influence of corona on the mutual coupling between conductors is also taken into account. Results show that corona (using any of the models) produces an increase in the overvoltage amplitudes, confirming that found in a previous work concerning single-conductor lines. It can also be seen that the results obtained by each model are quite different from each other. The effect of corona in mutual coupling should not be disregarded