State coordinated voltage control in an active distribution network with on-load tap changers and photovoltaic systems

Decreasing costs and favorable policies have resulted in increased penetration of solar photovoltaic (PV) power generation in distribution networks. As the PV systems penetration is likely to increase in the future, utilizing the reactive power capability of PV inverters to mitigate voltage deviations is being promoted. In recent years, droop control of inverter- based distributed energy resources has emerged as an essential tool for use in this study. The participation of PV systems in voltage regulation and its coordination with existing controllers, such as on-load tap changers, is paramount for controlling the voltage within specified limits. In this work, control strategies are presented that can be coordinated with the existing controls in a distributed manner. The effectiveness of the proposed method was demonstrated through simulation results on a distribution system.