| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of a power inverter that the charge inside the power converter must be discharged using a resistor, or the like, when the DC voltage is stopped at a level close to a rated voltage at the time of normal stoppage or failure stoppage. SOLUTION: A power converter comprising a multi-level inverter circuit 14 for driving an AC motor 15 by converting a DC voltage of capacitors 12, 13 connected in parallel into an AC voltage is provided with a reversible converter 19 for generating the DC voltage from an AC power supply 20. When the AC motor 15 is braked and stopped through the multi-level inverter circuit 14, operation of the reversible converter 19 is continued until the DC voltage drops down to a predetermined level in order to reduce residual charges in the capacitors 12, 13, thus enhancing safety and maintainability of discharge work significantly. |
