Abstract: A power conversion apparatus includes a transformer including a first winding, a second winding, and a third winding, a first switching circuit connected between an external power supply and the first winding, a second switching circuit connected between a main battery and the second winding, and a third switching circuit connected between an auxiliary battery and the third winding. The first switching circuit includes a power factor correction circuit, a smoothing capacitor configured to smooth a voltage of direct-current power output from the power factor correction circuit, and a relay provided in a power line between the smoothing capacitor and the first winding.