Abstract: According to an embodiment, a power converter (1) includes a main circuit (10), an electrification control unit (25), and an analysis unit (24). The main circuit includes a plurality of switching devices (Q1 to Q4), converts direct-current power into multiphase alternating-current power through switching of the plurality of switching devices, is able to supply the multiphase alternating-current power to an alternating-current load (2) connected to an output side, and output a detection result of a device short circuit current flowing in each of the plurality of switching devices. The electrification control unit electrifies the plurality of switching devices for a predetermined time based on one of a plurality of pre-decided analysis test electrification patterns.

Abstract: Power conversion equipment which can detect a short circuit failure of series connected smoothing capacitors is provided. The equipment includes a capacitor failure detecting circuit having switch units, exciting resistors, contact resistors, and diodes. A switch unit is provided with an exciting circuit and a contact circuit, and when a predetermined current flows through the exciting circuit, the contact circuit is closed. The exciting circuit and an exciting resistor are alternately connected in series, and the contact circuit and a contact resistor are alternately connected in series. These serially-connected circuits are connected in parallel with each capacitor. When excitation of a switch circuit having a lowest potential is turned OFF, it is judged that one or more of the series connected capacitors has failed via a short circuit.

Abstract: To provide a power conversion equipment which can detect short circuit failure of series connected capacitors of a smoothing capacitor circuit 4. A capacitor failure detecting circuit is composed of the combination of switch units 7SW, exciting resistors 8R, contact resistors 9R, and diodes 10D. The switch unit 7SW is provided with an exciting circuit and a contact circuit, and when a predetermined current flows through the exciting circuit the contact circuit is closed. The exciting circuit of the switch unit 7SW and the exciting resistor 8R are alternately connected in series, and the contact circuit and the contact resistor 9R are alternately connected in series, corresponding to the number of the series connected capacitors, and these series circuits are connected in parallel with the capacitors.