| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a relay failure diagnostic device capable of reliably diagnosing a main relay for welding failure. <P>SOLUTION: The relay failure diagnostic device includes a relay control unit 10 that outputs on/off signals to the respective main relays 5, 7 on the (-) side and on the (+) side and controls connection/disconnection of each relay, a converter drive control unit 12 that outputs a drive command signal for driving a DC/DC converter 9 connected in parallel with an inverter 2 between a negative power line 4 and a positive power line 6, and a relay failure diagnosis unit 11. The diagnosis unit individually switches an on signal or an off signal and outputs them to the individual main relays 5, 7 through the relay control unit 10. It determines whether or not each main relay 5, 7 is welded based on variation in the output current and/or output voltage from the DC/DC converter 9 when a drive command signal is outputted from the converter drive control unit 12 to the DC/DC converter 9. <P>COPYRIGHT: (C)2011,JPO&INPIT |
