Rooftop PV systems with distributed batteries for voltage unbalance mitigation in low voltage radial feeders

Abstract

This paper discusses the alleviation of voltage unbalance (VU) in low voltage four-wire ungrounded distribution networks. Unbalanced allocation of distributed rooftop Photovoltaic (PV) ratings and loads creates considerable neutral current in the neutral line. Because of the size limitation or non-connection of distributed batteries, this paper proposes three strategies for using the available distributed energy storage to reduce VU and neutral potential under a high penetration of distributed rooftop PVs. VU mitigation algorithms are presented and implemented in the MATLAB/software environment.