| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a failure detection apparatus of the three-phase PWM inverter in which the need for a high-speed A/D converter is eliminated, and in addition, the voltage utilization factor of bus bar voltage can be increased. <P>SOLUTION: The failure detection apparatus is provided with a busbar voltage monitor circuit 56 for supervising bus bar voltage of a three-phase PWM inverter 52, an output voltage monitor circuit 55a for adding the output voltage of each phase of the three-phase PWM inverter 52 to additionally output the added output voltage via a filter, having low-pass characteristics with a cut-off frequency lower than the PWM carrier frequency, and a trouble determining means 60a for determining the three-phase PWM inverter 52 in trouble when an output voltage value output from the output voltage monitor circuit 55a is substantially equal to the voltage value, corresponding to 3/2 times the busbar voltage monitored by the busbar voltage monitoring circuit 56. <P>COPYRIGHT: (C)2008,JPO&INPIT |
