Integration of Distributed PV in Existing and Future UFLS Schemes

Abstract

In recent years, the amount of photovoltaic panels in residential areas has steadily increased. As these areas are usually the first to be disconnected by under frequency load shedding schemes, the adequacy of the scheme comes under pressure. Already now, during some hours of the day, several feeders have more local generation than load. Disconnecting those feeders during an under frequency event, would aggravate the situation. Furthermore the impact of disconnecting feeders with significant load and generation, is much higher than is expected based on the netted load. Therefore, this paper proposes several new feeder ranking methodologies to take the distributed generation into account in the under frequency load shedding scheme. For each of the proposed methodologies, the advantages, disadvantage and hardware requirements are listed. Finally, these methodologies have been simulated on data provided by the French DSO.