| 摘要 |
PROBLEM TO BE SOLVED: To prevent breakage of two switching elements on the neutral point side, both in stopping operation at the occurrence of an anomaly and in restarting operation at normal return. SOLUTION: To stop operation of an inverter device, when a anomaly occurs; and switching elements 8a and 8d connected with a high voltage-side direct- current bus-bar or low voltage-side direct-current bus-bar are turned off, before the two switching elements 8b and 8c on the neutral point side are turned off. To restart the operation at normal return, the two switching elements 8b and 8c on the neutral point side are turned on, before the switching elements 8a and 8d connected with ah high voltage-side direct-current bus-bar or low voltage- side direct-current bus-bar being turned on. Thus large voltage stress will not be applied to the two switching elements 8b and 8c on the neutral point side, and the breakage thereof is prevented. |
