| 摘要 |
PURPOSE:To suppress the rise of a DC voltage at normal time by forcibly closing the switching element of an energy consuming circuit by the output from malfunction detecting means for the prescribed period. CONSTITUTION:An inverter for driving an AC motor 5 is composed of a rectifier 2 for obtaining a DC voltage from an AC power source 1, a smoothing condenser 3, and an inverter 4. The inverter 4 is controlled by the outputs of the rotating speed detector 5 of the motor 5 and a current detector 7 through a speed controller 8, a current controller 9 and a switching control amplifier 10. In this case, a malfunction time switching controller 16 is added between a malfunction detector 15 and the switching control amplifier 14 of an energy consuming circuit 11. Thus, the controller 16 outputs a signal for forcibly conducting (closing) the switching element 11a of the circuit 11 by the malfunction detection output from the detector 15 for the prescribed period to suppress the abnormal rise of the DC voltage. |
