| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent variations in the output of an induction motor in switching when driving the induction motor by switching to another inverter device when one inverter device fails. <P>SOLUTION: There are provided: a plurality of inverter devices 1, 2; diverter switches 17, 18a for changing the output of the plurality of inverter devices for supplying to one induction motor 4; and a switching control unit that switches the diverter switch to another inverter device 2 based on a failure detection signal of one inverter device 1, and starts the inverter device 2 to drive the induction motor. The switching control unit has: a frequency/phase detection circuit 22-2a for detecting the frequency and phase of a terminal voltage in the induction motor continuously; and a starting frequency/phase setting apparatus 25-2 for controlling frequencies and phases when starting the other inverter device, by following the detection value of the frequency/phase detection circuit when the failure signal is input. <P>COPYRIGHT: (C)2008,JPO&INPIT |
