Patent ID: 9048735
Filing Date: 2015-06-02
Classification: H02M

Abstract:
1. A power supply device, comprising: a first DC power source; a first switching element and a flywheel semiconductor element which are respectively connected to the first DC power source in series; a reactor, a second switching element, and a second DC power source which are respectively connected in series to a node between the first switching element and the flywheel semiconductor element; a drive control unit for driving the first switching element and the second switching element; a charge circuit for charging a first line connected between the second switching element and the reactor; a first voltage detection circuit for detecting a line voltage of the first line; an abnormality determination circuit for determining presence and absence of abnormality based on a control state of the drive control unit and a detection voltage of the first voltage detection circuit; a second voltage detection circuit for detecting a voltage of the second DC power source; and a diode connected in parallel to the second switching element, the diode including an anode terminal connected to the reactor side and a cathode terminal connected to the second DC power source side, wherein: the abnormality determination circuit determines that the flywheel semiconductor element is in a short-circuit failure state when the detection voltage of the first voltage detection circuit is lower than a predetermined voltage under a state where the drive control unit turns OFF the first switching element and the second switching element, the charge circuit comprises a resistor and a switch, when the detection voltage of the first voltage detection circuit is equal to or higher than a predetermined voltage under a state where the drive control unit turns OFF the first switching element, the second switching element, and the switch of the charge circuit, the abnormality determination circuit determines that at least one of the first switching element and the second switching element is in a short-circuit failure state, and when the detection voltage of the first voltage detection circuit is higher than a detection voltage of the second voltage detection circuit by a voltage drop of the diode under a state where the drive control unit turns OFF the first switching element, the second switching element, and the switch of the charge circuit, the abnormality determination circuit determines that the first switching element is in a short-circuit failure state.