| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the rise of a terminal voltage caused by the overcharging of a smoothing capacitor, when all switching elements that constitute a voltage-type inverter are controlled into off-states. <P>SOLUTION: This inverter device for motor drive comprises: a rectifier 2 that rectifies an AC voltage; the smoothing capacitor 3 that smoothes a DC voltage output by the rectifier 2; and the voltage-type inverter 4 that converts main circuit voltages appearing at both ends of the smoothing capacitor 3 into AC voltages applied to a motor 5 by the switching operation of the semiconductor switching element. The inverter device also comprises a control means that makes the semiconductor switching element constituting the voltage-type inverter 4 conduct the switching operation so that a current flows to the motor 5 when the main circuit voltages appearing at both the ends of the smoothing capacitor 3 become higher than a threshold voltage, when the semiconductor switching elements that constitute the voltage-type inverter 4 stop their swithcing operations. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
