| 摘要 |
PROBLEM TO BE SOLVED: To provide a power conversion device which comprises a state diagnosis function for a cutoff switch which cuts off power supply in the case of a fault in a control power supply part and is safely stopped while protecting circuits even if double faults occur.SOLUTION: The power conversion device comprises at least an arithmetic processing part 50A, a driving part 60, a safety part 40, a control power supply part 10 and a power supply diagnosis part 20A. The power supply diagnosis part 20A includes a cutoff switch 23, a comparator 21 and a transistor 22 that is a reference voltage changeover switch, and is configured to control opening/closing of the cutoff switch 23 using a diagnosis signal Sthat is outputted from the arithmetic processing part 50A, and a monitoring voltage that is outputted from the power supply diagnosis part 20. The arithmetic processing part 50A diagnoses the presence/absence of a short-circuit fault and an open-circuit fault in the cutoff switch 23, based on the logic Sof the diagnosis signal and a logic of a safety power supply signal Scorresponding to a level of the monitoring voltage, and stops operation of the driving part 60 in accordance with a PWM signal when the fault is determined.SELECTED DRAWING: Figure 2 |
