Equivalent Circuit Model for Calculation of Ground Potential Rise in Wind Turbine Grounding Systems

The ground potential rise caused by lightning is an important technical index for lightning protection design of wind turbines. A realistic approach is presented in this paper to calculate the ground potential rise in wind turbine grounding systems under lightning stroke. The electrical parameters of the grounding conductors are given by resistance, conductance, capacitance and inductance. The soil ionization due to dissipating lightning current can be taken into account by the effective radius estimated by the critical electric field intensity of soil ionization. According to the electrical parameters, the grounding conductors are replaced by π‐type circuit units and the circuit model is built for transient analysis of the single wind turbine grounding system and interconnecting configurations of multiple wind turbine grounding systems. The calculated results from the circuit model are compared with the measured ones to perform the model verification. Then, the circuit model is implemented into calculation of lightning transient responses in wind turbine grounding systems with attention to the ground potential rise.