| 摘要 |
PROBLEM TO BE SOLVED: To achieve correct protection even at an ON failure of a switching element.SOLUTION: An inverter 11 includes: a plurality of switching elements 21-26 disposed on an upper arm and a lower arm to form a serial connection body; and free wheel diodes 31-36 respectively connected to the switching elements 21-26 in inverse parallel. In a period when a forward current flows through the free wheel diodes 31-36 on either side of the switching elements 21-26 on the upper and lower arms, drive units 41-46 switches the switching elements 21-26, to which the wheel diodes 31-36 thereof are reversely connected, to an OFF state. Based on that the actual value of a current flowing through a coil deviates from a current instruction value, a control device 14 determines that an ON failure occurs in the switching elements 21-26.SELECTED DRAWING: Figure 1 |
