| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect operating state, especially, the speed and step-out of a synchronous motor (motor) with a field system easily. <P>SOLUTION: The system for driving a motor 12 by using an inverter 11 while making the voltage applied to the winding substantially proportional to the frequency comprises a means 27 for detecting the peak value of a DC bus current flowing between a DC voltage section and the inverter 11, and a means 28 for extracting the vibration components of the current peak value thus detected, and the rotational speed or step-out of the motor can be detected based on the output from the vibration component extraction means 28. <P>COPYRIGHT: (C)2008,JPO&INPIT |
