Analysis of Wind Farm Grounding Systems During a Direct Lightning Strike

Designing and calculating a ground circuit is unfortunately not an easy task. The problem is even more complex when it comes to a grounding circuit made up of several interconnected grounding systems, as in the case of wind farms. The measurement, which is generally very expensive, is not sufficient and the engineers then use numerical modelling to try to find the optimal solution. In this paper we propose a simplified numerical modelling allowing to simulate both an individual grounding system and a set of grounding systems interconnected by bare or insulated conductors (example: grounding circuit of a wind farm). This modelling using the electromagnetic topological formalism for a complex network, which is composed of towers and buried conductors, is developed from the theory of transmission lines (TL) and makes it possible to consider the variation of soil electrical parameters with frequency. To validate this model, we compare our calculation results for Ground Potential Rise (GPR) with those recently published in the literature.