Inverter Ground Fault Overvoltage Testing

This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported extent in certain scenarios. The total voltage duration and the maximum continuous time above various voltage thresholds are presented here, as well as other test parameters. We also present brief investigations into the effects of changing inverter overvoltage and overfrequency trip settings, the effect of anti-islanding controls, and the effect of wye-connected loads.