| 摘要 |
PROBLEM TO BE SOLVED: To simplify the circuit of an inverter device and reduce the cost of the inverter device even if the inverter device outputs a three-phase AC voltage, by a method wherein one high dielectric strength photocoupler is provided in an interface circuit. SOLUTION: An upper arm IGBT 12a has a gate driving circuit 21, and a lower arm IGBT 12b has a gate driving circuit 14. If a grounding occurs in a feeding route from an inverter device 20 to a load 3 and the grounding current is applied to the IGBT 12a, the collector current of the IGBT 12a is cut off for a predetermined period by the gate driving circuit 21 and, at the same time, the operation of the inverter device 20 is stopped by a control circuit 15a and the stoppage is displayed outside to simplify an interface circuit 16a. |
