Experimental validation of voltage unbalance suppression method of high voltage distribution system using static capacitors

In recent years, rapid introduction of photovoltaic generation systems (PVs) causes voltage rise in distribution systems. In addition, residential PVs cause voltage unbalance in distribution systems, as these PVs are mostly single-phase connections. For these reasons, in order to control voltage in distribution system, it is important to suppress voltage unbalance. Voltage unbalance can be suppressed by power electronics equipment such as static var compensator, but it is high cost. So, the authors focus on static capacitor (SC), because SC is low cost compared to static var compensator. In this study, the authors propose a new method of controlling single phase SCs to suppress voltage unbalance by estimating voltages after SCs control. And, we verify the effect of the method by experiments. © 2016 The Institute of Electrical Engineers of Japan.