Voltage control for a loop distribution system with renewable energy sources

This paper describes and verifies a voltage control for a loop distribution system. The proposed method adopts SCADA system based on voltage data from IT switches, which are sectionalizing switches with sensor installed at 6.6kV distribution line. The proposed voltage control combines centralized control of a LRT and autonomous control of decentrally-allocated RESs. The tap change control of LRT takes the major role of the proposed voltage control. It is the extended type of LDC method which is generally adopted, and minimizes voltage deviations based on voltage data from each IT switch. The output power control of RES additionally and autonomously supports the voltage control when the voltage violation from the upper limit is unavoidable. The reactive power control in the vacant capacity of RES's inverter mainly works, and the active power control works when not enough. In order to check the validity of the method, the experimental simulations using an analog distribution system simulator are carried out. This study is supported by a specially-promoted research grant of Power Academy in 2009 from the Federation of Electric Power Companies of Japan.