POWER CONVERSION DEVICE AND FAILURE DETERMINATION METHOD

A power conversion apparatus includes a filter capacitor, a contactor to electrically connect the filter capacitor to a power source or electrically disconnect the filter capacitor from the power source, and a failure determiner to determine whether a failure occurs in the contactor. When the contactor is kept closed during a determination period since closing of the contactor and a reduction in the voltage in the filter capacitor during the determination period is greater than or equal to a reference value, the failure determiner determines occurrence of a failure in the contactor.