POWER CONVERSION APPARATUS, MOTOR DRIVE APPARATUS, AND REFRIGERATION AIR-CONDITIONING APPARATUS

摘要

A power converting device includes a rectifying circuit 2 that rectifies voltage of an alternating-current power supply 1; smoothing means 8 that smoothes output voltage from the rectifying circuit 2; short-circuiting means 4 that is disposed more closely to the alternating-current power supply 1 than the smoothing means 8 and that short-circuits the alternating-current power supply 1 and controls at least one of electric current and voltage; a reactor 3 that is disposed more closely to the alternating-current power supply 1 than the short-circuiting means 4; one or more backflow preventing elements 5 that prevent electric current from flowing backward from a load 9 side toward the alternating-current power supply 1; commutating means 7 for performing a commutation operation for causing electric current to flow toward a different path that is connected in parallel with the one or more backflow preventing elements 5; malfunction detecting means 105 for detecting a malfunction of the commutating means 7; and switching control means 103 that performs operation control of the commutating means 7 in accordance with detection by the malfunction detecting means 105.