A wind power generation system includes a power generator body, an auxiliary device that assists the power generator body, and a power conversion apparatus that converts first AC power generated by the power generator body to second AC power, and outputs the second AC power to an electric power grid. The power conversion apparatus includes a first power conversion circuit, a second power conversion circuit, a power storage element that receives DC power from the first power conversion circuit via a first passing point, a breaker, and a control unit. When the power generator body is in a power generation standby state, the control unit sets a parallel-off mode and controls the second power conversion circuit to convert power of the power storage element to third AC power having a preset voltage. The auxiliary device is configured to receive the second AC power or the third AC power.