A comprehensive analysis of the effect of frequency-dependent soil electrical parameters on the lightning response of wind-turbine grounding systems

摘要

The impact of frequency-dependent soil electrical parameters on the lightning response of typical wind turbine grounding systems is investigated. It is shown that the frequency dependence of soil parameters is responsible for decreasing the ground potential rise and, thus, the impulse impedance and impulse coefficient of the grounding systems. This effect is more pronounced for high-resistivity soils and fast current pulses. It is also shown that, considering typical dimensions of actual wind turbine grounding systems and soils with resistivity higher than 300 Omega m, the impulse impedance seen by each single wind turbine is expected to be lower than the low-frequency grounding resistance.