| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique that detects welding of a system main relay without using a discharge device in a power-supply control device supplying a stepped-up power-supply voltage to an inverter.SOLUTION: A power-supply control device 2 includes a step-up circuit 4. The step-up circuit 4 includes a low-voltage-side capacitor 12 connected to a low-voltage side, a reactor 14 having one end connected to a positive terminal on the low-voltage side, an upper-arm switching circuit connected between the other end of the reactor and a positive terminal on a high-voltage side, and a lower-arm switching circuit connected between the other end of the reactor and a ground terminal on the high-voltage side. A controller 8 of the power-supply control device 2 opens the upper-arm switching circuit, repeats opening and closing of the lower-arm switching circuit, and determines that a relay is welded when the reduction rate of a current flowing through the reactor 14 is smaller than a predetermined reduction rate value. |
