Transient characteristics of wind turbine grounding system in high soil resistivity area due to lightning strike

The lightning current causes a change on the potential rise of grounding system as it is transmitted through the tower to the grounding system under the condition that the wind turbine is subjected to a lightning strike. The paper deals with the impact of the structure of grounding system on the lightning transient characteristics of wind turbine. The instantaneous potential of the grounding system is calculated based on the method of moments. Afterwards, the corresponding time domain transient response is obtained by means of the Inverse Fourier Transform (IFT). The influences of the structure of grounding system on the potential rise and the impedance of grounding system have been obtained. It shows that the natural grounding body significantly affects the amplitude of the potential rise of grounding system. Adding vertical electrodes leads to an obvious decrease on the impedance of grounding system. Meanwhile, the shielding effect between vertical grounding electrodes has significant influences on the transient impedance of grounding system.