Distributed Energy Resource Overvoltage During Un-Intentional Islanding

Abstract

During unintentional islanding, the isolated system is energized solely by a distributed energy resource (DER). If there is no ground source, the overvoltage may appear on un-faulted phase when the ground fault occurs. Most DERs nowadays are inverter based, the characteristics of which are totally different from synchronous generators; thus, the impact mechanism of source, load and neutral ground resistor (NGR) on the overvoltage may change. This paper conducts comparative analysis of the impact on the overvoltage between synchronous generators and Inverter-Interfaced DERs using sequence network. The simulation has been done on the real distribution system model to validate the theoretical analysis.