| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power converter capable of suppressing a range of a failure. <P>SOLUTION: The power converter has a control circuit 10 which controls main elements Q1, Q4 and AC switch elements Q2, Q3 so that a U-phase unit 2U may operate as a three-level conversion circuit. When detecting that at least one of the AC switch elements Q2, Q3 breaks down, the control circuit 10 turns off the main elements Q1, Q4 and AC switch elements Q2, Q3. When operation of the U-phase unit 2U continues with the AC switch element Q2 or Q3 broken down, surge voltage becomes large by two-level operation. For this reason, the main element Q1 or Q4 may be damaged. The power converter is suspended by turning off the AC switch elements and main elements in all phases, thereby preventing the break-down from being expanded. <P>COPYRIGHT: (C)2013,JPO&INPIT |
