| 摘要 |
PROBLEM TO BE SOLVED: To locate the faulty semiconductor device of an inverter device, and moreover to aim at downsizing and reduction of the number of wirings among related apparatuses. SOLUTION: This system is provided with the gate drive power sources 21-23 which supply the semiconductor elements Q1-Q4 for each unit of inverter units 11-13 with gate drive power via gate drive circuits 31-34, a constant current source 8 which charges a smoothing capacitor Cf of each unit with DC constant currents and issues a signal when the charge voltage of each capacitor reaches a predetermined value, a control circuit 6 which directs normal inverter operation and in addition turns on or turns off the elements Q1-Q4 of each unit mentioned, according to a prescribed order at fault diagnosis, and a fault decision display circuit 7 which decides on each propriety of the time required for charging and locates the semiconductor device of each units in faulty conditions. |
