Effective Grounding Criteria for High Penetration Inverter Based Resources in Distribution Networks

This paper presents effective grounding criteria for high penetration inverter-based resources (IBRs) in distribution networks. It demonstrates that traditional methods of employing supplemental grounding exclusively does not prevent excessive ground fault overvoltages (GFOV) where adoption levels of IBRs exceed a distribution feeder minimum load. Definitions and requirements are presented for quantifying and mitigating IBR-caused GFOV such that the distribution utility is protected. The requirements are tested using a real, albeit generic case study within the EMTP-RV environment to demonstrate their efficacy.