A plurality of gate drive circuits each drive a gate of a corresponding one of a plurality of switching elements included in a converter and an inverter. Each gate drive circuit includes a gate driver and a power source circuit. The gate driver drives the gate potential of the switching element to a potential corresponding to H or L level, in accordance with the gate signal input from a controller to the gate electrode of the switching element. The power source circuit supplies power to the gate driver. When a first switch is ON and a second switch is OFF, the controller, upon detection of an abnormality of the power source circuit of the gate drive circuit, turns on the second switch and turns off the first switch. The gate drive circuit maintains the gate potential of the switching element during the period from when the abnormality of the power source circuit is detected to when the second switch is turned on.