An Optimized Decentralized Control Strategy of Grid-Connected Residential Photovoltaic Inverters Based on Voltage Sensitivity Matrix

Abstract

Due to the mismatch between the residential electrical load and the output power of the rooftop photovoltaic (PV) systems, node voltages in a low voltage distribution network (LVDN) may exceed the allowable upper limit during the daytime and drop far below the lower limit at night. Existing LVDN voltage regulation methods based on reactive power control of the rooftop PV inverter usually regulate all the inverters using the same control strategy with identical control parameters, although PV inverters at different nodes have different voltage sensitivities to active and reactive power flows. In this paper, an optimized decentralized control strategy of residential PV inverters based on voltage sensitivity matrix is proposed, and different control parameters would be determined and applied to each PV inverters at different LVDN nodes. The proposed strategy provides an optimal control framework for the rooftop PV inverters to maintain voltage within the normal range under varying active power generated by the PV systems, and simulation results verify that the total reactive power output of the PV inverters can be effectively reduced.