A power converter that includes a rectifier rectifying a voltage supplied from a three-phase AC power supply, a voltage step-down circuit including a voltage step-down switching element, a reactor, a backflow prevention element, and a smoothing capacitor and stepping down a DC voltage supplied from the rectifier, and an inverter circuit converting the DC voltage smoothed by the smoothing capacitor into an AC voltage. The power converter includes an imbalance determining unit determining, based on states of the voltage step-down circuit and the smoothing capacitor, whether or not voltage imbalance has occurred in the three-phase AC power supply and a voltage step-down control unit performing switching of the voltage step-down switching element in a case where the imbalance determining unit determines that the voltage imbalance has occurred.