| 摘要 |
<P>PROBLEM TO BE SOLVED: To sustain operation within a possible range using a part of an inverter circuit by disconnecting a power semiconductor element and its driving circuit quickly upon detecting an overcurrent to the power semiconductor element. <P>SOLUTION: An inverter circuit 2 is constituted of one switching section SW consisting of IGBTs 3a and 3b connected in parallel and each gate drive circuit 5 for driving each IGBT 3 is connected in parallel with a gate driving power supply 11. A fuse 31 is provided on the collector side of each IGBT 3 and a fuse 32 is provided at the positive side power supply input section of each gate drive circuit 5. When an overcurrent flows due to an abnormality in the IGBT 3a, for example, the fuses 31a and 32a blow out to insulate the IGBT 3a from the collector side potential thus insulating its gate drive circuit 5a from the positive side power supply potential. The overcurrent has no effect on the normal IGBT 3b and its gate drive circuit 5b side and since normal operation is possible, inverter operation can be sustained using the normally operable IGBT 3b. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
