The Self-Responsive Voltage Control Method for Distributed Photovoltaic Inverters

With a high-proportion of distributed photovoltaic (D-PV) systems connect to distribution network (DN) feeders, the random fluctuations in photovoltaic (PV) output can lead to notable voltage variations at different points along the feeder. In cases of high PV generation, the voltage at the feeder's end may rise excessively, while during periods of low or no PV generation, the voltage can fall below acceptable levels. These fluctuations pose serious challenges to both the safe operation of the DN and the power quality. To tackle this, this paper introduces a self-responsive voltage control method for D-PV inverters. By analyzing the active/reactive power coupling characteristics of D-PV inverters, the mechanism by which reactive power control from D-PV inverters influences feeder voltage is explained. A reactive voltage control model for PV systems is then developed, with a self-responsive threshold set for D-PV inverters to facilitate automatic reactive voltage control. The results of simulation demonstrate that this method significantly enhance the voltage stability of DN feeders incorporating D-PV.