Reactive Power Management of PV Systems by Distributed Cooperative Control in Low Voltage Distribution Networks

A distributed control strategy is proposed to enhance voltage regulation and reactive power sharing in Low Voltage (LV) distribution networks with high penetration of Photovoltaic (PV) systems. This paper investigates the disadvantages of the available methods that their aims are modifying the voltage profile levels of buses and managing the reactive power of PV inverters. Next, through the proposed method, PV systems reduce the deviation of voltage profile by absorbing or injecting reactive power. This paper eliminates the disadvantages of the available control method by the combination of distributed and local control approaches. Indeed, a local droop characteristic determines the reactive power ratio of the worst bus voltage deviation at a critical bus. Afterwards, the distributed control coordinates all PV systems to operate according to the PV system that locates at the critical bus. In addition, the proposed technique prevents PV systems from active power curtailment and manages reactive power sharing among PVs based on their reactive power ratings. A radial LV distribution system with seven PV systems is presented to analyze the proposed procedure. Simulation consequences are demonstrated to confirm the effectiveness of the control method for decreasing voltage deviation and precise reactive power sharing in the distribution network with PV systems.