| 摘要 |
PURPOSE:To enable to continuously operate a PWM voltage inverter even when power is interrupted for a long period of time by utilizing as the controlled power source of the inverter an AC power source and the regenerative voltage of the inverter and switching and using the voltage detecting means. CONSTITUTION:An AC power source 1 is converted via a rectifier 2 to DC, which is smoothed via a capacitor 3, is then converted into AC via an inverter bridge 4, and power is supplied to a motor 5. AC voltage from the power source 1 and the regenerative voltage Vu-o of the inverter are used for the controlled power source, the outputs of transformers 6, 26 are converted into DC via rectifiers 20a-20e, 25a-25e, and are smoothed via condensers 21a-21e. A control circuit 14A which uses as a power source a constant-voltage circuit 22, and base drive circuits 24b-24e for driving the transistors 41-46 of the bridge 4 are provided, are switched by the voltage detector 27 of the power source 1 and the regenerative voltage detector 28 of a motor 5, thereby enabling to continuously operate even when the power is interrupted for a long period of time. |
