DIRECT-CURRENT POWER SUPPLY DEVICE, MOTOR DRIVING DEVICE, AIR CONDITIONER, AND REFRIGERATOR

摘要

This DC power source device is provided with: a rectifier (2) connected to a power source (1); a charge accumulation unit configured from a first capacitor (6a) and a second capacitor (6b) connected in series; a switch unit (7) configured from a first switching element (4a) and a second switching element (4b) connected in series, and reverse current prevention elements (5a, 5b) that, by means of inhibiting reverse current, suppress a reverse current of the electrical charge from the charge accumulation unit; an inductor (3); a control unit (8) that controls the operation of the first switching element (4a) and the second switching element (4b); and a DC voltage detection unit (10) that detects a first cross-terminal voltage that is the voltage across the first capacitor (6a) and a second cross-terminal voltage that is the voltage across the second capacitor (6b). The control unit detects a short-circuit fault of the first switching element (4a) and the second switching element (4b) on the basis of the voltage difference between the first cross-terminal voltage and the second cross-terminal voltage.