Power conversion apparatus, motor drive apparatus, and refrigerating and air-conditioning apparatus

Provided is a power conversion apparatus, which is provided with: a three-phase alternating current reactor that is connected to a three-phase alternating current power supply; a three-phase diode bridge; a plurality of smoothing capacitors connected in series; a bidirectional power switch that is provided between the alternating current input side of the three-phase diode bridge and the middle points of the smoothing capacitors; and a controller that controls the bidirectional power switch. The controller controls the bidirectional power switch to perform switching operation for a predetermined period, said power switch corresponding to a phase having the intermediate potential of the three-phase alternating current power supply.