Field-Circuit Coupling Analysis Method for Grounding Devices Considering Inductance Effect

Experiments show that the inductance effect of grounding device under impulse current is especially obvious at low soil resistivity. Based on the theory of transmission line and the theory of finite element dispersion analysis, a transient analysis model of grounding device is established by field-circuit coupling method (FCM). The method considers the electromagnetic coupling between grounding conductors and can accurately reflect the impact characteristics of grounding devices under low soil resistivity. This method is used to calculate the impedance value and impedance angle of a single grounding body in full frequency domain within 0-100kHz, which is basically consistent with the results of CDEGS. The divergence of the conductor segment is compared and the results are in good agreement. Therefore, the field-circuit coupling model can effectively analyze the impact characteristics of grounding devices.