VOLTAGE CONTROL DEVICE, CONTROL METHOD THEREOF AND VOLTAGE CONTROL PROGRAM

An object is to provide voltage control having responsiveness without causing any problem in the operation of the utility grid, by using inexpensive equipment that has been conventionally used. Provided are a control-amount separating section (21) that separates, when it is determined that an interconnection-point voltage (Vr) at an interconnection point where a wind turbine (2) is connected to a utility grid (1) deviates from a target value, a target control amount for reactive power for matching the interconnection-point voltage (Vr) with the target value into a first control amount serving as a control amount for reactive power that is caused by a fluctuation in active power at the interconnection point and a second control amount serving as a control amount for reactive power that is caused by a change in a power flow in the utility grid (1); a wind-turbine control device (22) that controls the switching device on the basis of the first control amount; and a capacitor-bank control device (23) that controls the capacitor bank (5) on the basis of the second control amount.