| 摘要 |
PROBLEM TO BE SOLVED: To suppress an excessive short-circuit current via an inverter.SOLUTION: Failure diagnosis is performed on an inverter 30 that drives a three-phase motor 10 by forming upper and lower arms for each of phases from upper arm side switching elements 32u, 32v and 32w and lower arm side switching elements 34u, 34v and 34w. A controller 70 inputs a voltage at a node N that mutually connects one-side ends of a plurality of first resistors R1 from a circuit formed by connecting the node N with a ground via a second resistor R2 and connecting other-side ends with points A, B and C between upper and lower arms in one-to-one correspondence. The controller turns off a first switch SW1 that is provided in a positive electrode bus 24p between a power source and the upper arm, turns off a second switch SW2 that is provided in parallel with the first switch SW1 and in series with a third resistor R3, and turns on a third switch SW3 that is provided between the power source and the node N and in series with a fourth resistor R4. The fault diagnosis is performed based on the voltage at the node N in the case where ON/OFF of the switching elements is set in a predetermined pattern.SELECTED DRAWING: Figure 1 |
