Parametric analysis and simplified calculations of fault current split for wind power plant grounding system safety design

Grounding systems for Wind Power Plants (WPP) are an interconnected collection of numerous individual grounding systems at the base of each Wind Turbine Generator (WTG). The complexity of the large interconnected system can be analyzed using advanced grounding software; however, methods for calculating accurate safety performance of individual WTG grounds by hand are not well established. This paper presents a parametric analysis of WPP grounding systems through software with the objective of determining accurate and realistic current split factors to be used in analysis of WTG grounding systems without the use of advanced software. Based on this approach, equations were developed to provide a simplified calculation method. The results presented provide practical approximations of the current returning to remote earth through the grounding system of a WTG using both overhead and underground collector systems in various soil conditions.