Active and reactive power management of photovoltaic-based interline dynamic voltage restorer in low voltage distribution networks

A dynamic voltage restorer (DVR) is a series connected device that can support the voltage at existing critical loads during voltage sags. Voltage restoration may need active and/or reactive power injection into the distribution feeder. Due to the limitation of the DVR energy storage element, the Interline Dynamic Voltage Restorer (IDVR) can be used to mitigate the voltage sag in distribution systems. In a two-line IDVR system, the active power required for voltage restoration is obtained from the neighboring feeder. The maximum active power that can be injected by the neighboring feeder depends on its load displacement factor. Renewable energy sources and batteries can be connected across the common DC link to share the required active power in case of insufficient mitigation of the voltage sag by the neighboring feeder or both feeders are experiencing simultaneous voltage sag. This paper focuses on active and reactive power management of a photovoltaic-based (PV-based) IDVR for supporting the system during voltage sags to enhance the system reliability and power quality. A complete strategy with operational constraints for a two-line PV-based IDVR in low voltage distribution networks is proposed in this paper. Simulation and practical results are presented to substantiate the proposed concept.