| 摘要 |
PROBLEM TO BE SOLVED: To prevent the DC voltage of an inverter from rising by a method in which a resistor is inserted between the grounding part of the shield of a shielded power line with which the inverter is connected to a three-phase induction motor and an actual grounding point or between the grounding part of an inverter input power supply apparatus and an actual grounding point. SOLUTION: A resistor 17 is inserted between the grounding part 143 of a shielded line and an actual grounding point 15. With this constitution, the maximum value of a resonance current produced by a coil and a capacitor can be suppressed and, further, the resonance can be attenuated. As a result, the resonance current is reduced and a current by which a DC voltage smoothing capacitor 133 in an inverter 13 is charged is reduced, so that the rise of the DC voltage of the inverter 13 can be avoided. |
