Simplified Formulae Method for Estimating Wind Turbine Generators Ground Resistance

摘要

This paper aims to extract simple formulae for estimating the ground resistance values of wind turbines (WT) installed at terrains that can be modeled by a two-layer soil structure. Several grounding system configurations, applied in construction practice, were used as case studies. Various combinations of soil resistivity values for the upper and the lower layer of a two-layer soil model, as well as for the depth of the upper layer, are carefully selected in order to cover a wide range of nonuniformities in the ground. Thereafter, the ground resistance value is estimated from software simulations, for each combination among the examined two-layer models and the predefined ground electrodes geometry. Furthermore, regression analysis techniques are applied to create a model describing the behavior of the ground resistance and to fit the equations using data from the aforementioned simulations. The whole procedure has been algorithmized, so that the process is easily replicable. Finally, the model is verified and its accuracy is tested through applicable validation datasets.