| 摘要 |
<P>PROBLEM TO BE SOLVED: To determine simply and inexpensively deterioration of semiconductor elements constituting a power conversion device without dismantling the elements from a device. <P>SOLUTION: A series circuit of resistors R1, R2 is connected to both ends of a direct-current charging part (Cd) of the power conversion device Conv comprising semiconductor elements (IGBT) Q11-Q23, and a switch S1 and a current detector CT are provided between the neutral point of the resistors R1, R2 and alternating-current output terminals u, v, w. The switch S1 is closed during the off-state of Q11-Q23 at the direct-current voltage application time, and deterioration determination of the elements Q11-Q23 can be performed from the direction of the current flowing at that time and a current value. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
