| 摘要 |
PROBLEM TO BE SOLVED: To detect a ground fault when an inverter is in a stop without switching the semiconductor bridges at the inverter output end. SOLUTION: The inverter switches the current of a direct-current bus (2), obtained by rectifying alternating-current power through diodes (d1 to d6) and filtering it through a capacitor C, through the plurality of sets of the semiconductor bridges (6) and outputs it as alternating-current power. When the inverter is in a stop, any ground fault at the inverter output end is detected by comparing the potential difference between at least one phase of the inverter output end and one pole of the direct-current bus with a reference voltage at a comparator (11). |
