Voltage control by using PV power factor, var controllers and transformer tap for large scale photovoltaic penetration

InJapan, introduction of a large capacity of photovoltaic power(PV) is planned to solve environmental problems. However, a large penetration of PV will cause several problems in power systems, such as the increase in voltage from decreased load demands associated with the active power output of PV systems, and voltage fluctuation caused by PV system output variation. In this paper, we focus our attention on voltage and reactive power control for large penetration of PV. First, we propose a voltage control method for var controllers (VC) and transformer taps (TAP) by using VMPI-i sensitivity. Second, we propose a coordinating control for the power factor of PV system (PF), VCs and TAPs. In our proposed method, voltage fluctuation is controlled by PF regulation and voltage increase is controlled by VCs and TAPs. We simulate this control with the Ward-Hale system to verify the validity of the proposed method.