Reactive Power Control for LV Distribution Networks Voltage Management

The high photovoltaic (PV) penetration into existing distribution networks leads to voltage profile violation. The main objective of this paper is to study the interaction of traditional static synchronous compensator (STATCOM) with the reactive power capable PV inverter in order to provide voltage support to the low voltage (LV) distribution network. In this paper, we propose an effective coordinated voltage control structure. The control structure has a hierarchical approach where reactive power compensation by PV inverters is prioritized. The STATCOMs are only used when the PV inverters are not capable enough to provide or consume enough reactive power to provide the voltage support. Also, we show that the reactive power supply at night by the PV inverters can be an important resource for effective voltage regulation by using this technique. Data from the existing LV distribution network are used for a case study. The simulation results indicate that the proposed voltage control method is able to control both the over and under voltage situations for the test distribution network without curtailing any active power from PV.