Static variable compensator and voltage-control method

The purpose of the invention is to provide a voltage control method and static variable compensator capable of adjusting voltage in a single-phase AC power system. This static variable compensator is configured to generate a second axis voltage command from the difference between a DC voltage converted in a single-phase voltage-type AC-DC conversion circuit and an established DC voltage command. When there is an increase in the voltage of the single-phase AC power system (AC terminal voltage), the difference grows between the AC terminal voltage and the internal electromotive voltage; therefore, the static variable compensator performs PWM control so as to reduce the voltage at the AC terminal side of the single-phase voltage-type AC-DC conversion circuit. Because the voltage of the single-phase voltage-type AC-DC conversion circuit becomes lower than the voltage of the single-phase AC power system, reactive current can flow into the static variable compensator from the single-phase AC power system, and the voltage of the single-phase AC power system can be reduced.