An electric-vehicle power conversion device operates upon reception of a power supply from an overhead wire. Because an overhead-wire voltage is very high (for example, DC 1500 volts), even when the power supply from the overhead wire is blocked, a large amount of electric charge is still stored in a filter capacitor and the like within a main circuit. Therefore, there remains risk of an electric shock.
For example, an electric-vehicle control device described in Patent Literature 1 mentioned below includes a series circuit that is constituted by a plurality of contactors and a resistor, and that is connected between a converter and inverters. At the time of inspection and maintenance of an electric vehicle, the contactors are switched on by a contactor control unit for a predetermined time so as to discharge electric charge in filter capacitors through the resistor. The control is performed as described above with consideration given to operators so as not to receive an electric shock even when they touch a conductive part at the time of inspection, maintenance, and the like of an electric vehicle.
USPTO Backgrounds
USPTO Backgrounds