| 摘要 |
In the present invention, the amount of increase in the amount of heat release of an inverter is increased by increasing the standing loss of an IGBT element in the inverter in order to prevent frost formation at an outdoor heat exchanger in an air-conditioning device. In the inverter (120), a step-down circuit is configured that can, as the gate-emitter voltage of the IGBT element, impart a power source voltage that is in accordance with the amount of charge accumulated at a bootstrap capacitor (128). During the frost-formation-preventing operation of the outdoor heat exchanger, the amount of charge accumulated at the bootstrap capacitor (128) is increased, the gate-emitter voltage is stepped down in accordance with the amount of increase, and it is thereby possible to increase the standing loss of the IGBT element. |
