Inverter arrangement and AC motor driving system.

摘要

In a multi series pulse width modulation inverter arrangement, an inverter arrangement which can continue the inverter operation, in particular, by preventing an overcurrent caused by an erroneous firing of a switching element therein is provided. The multi series inverter arrangement is constituted to be operative in three level mode and in two level mode. Even when an erroneous firing thereof due to noise is generated, the operation of the inverter unit (4) can be continued, the overcurrent due to the erroneous firing is eliminated, the present inverter arrangement can be used under a severe noise environment and outputs an AC output having a small amount of higher harmonics, moreover when the inverter arrangement is operating under a three level mode in a low efficiency region, the operating mode of the inverter arrangement is positively switched from the three level mode to the two level mode, thereby the operating efficiency of the inverter arrangement is enhanced.