Application of Fuzzy Modeling to Identify the Soil Resistivity of Dynamic Grounding System

Accurate identification of soil resistivity of dynamic grounding system is extremely important to define the operational safety and proper functioning of electric power system. Conventional methods can´t achieve good result due to non-linearity of grounding system. To cope with the problem, a novel approach based on fuzzy modeling is proposed. In this approach, T-S fuzzy model is employed to appropriate the non-linear process, fuzzy model is derived from input-output data by means of product-space fuzzy clustering, similarity driven rule base simplification is applied to detect and merges compatible fuzzy sets in the model and real-coded genetic algorithm is adopted to optimize model parameters. All these techniques make the fuzzy model transparent and accurate. Based on this approach, a simulation experiment is made. The result shows the approach yields accurate result with error less than 1.5%, other parameters such as grounding resistance, over voltage can also be identified in the same way.