| 摘要 |
<P>PROBLEM TO BE SOLVED: To protect a switching semiconductor switch against damage from an overcurrent without causing damage to a smoothing capacitor included in a DC section of a power conversion device for supplying AC power generated by switching from DC power to a motor to drive the motor. <P>SOLUTION: The power conversion device that detects a current supplied from the device itself to a motor by means of a current detection section and compares the current level detected by the current detection section with a threshold determinative of whether or not to activate an overcurrent protection function, and if the former exceeds the latter, performs an emergency stop of switching includes: a driving/braking determination section for determining whether an operation state of the motor is a driving operation state or a braking operation state; and a threshold setting section for setting the threshold in accordance with the operation state of the motor which sets the threshold lower when the braking operation state is found than when the driving operation state is found. <P>COPYRIGHT: (C)2013,JPO&INPIT |
