| 摘要 |
PURPOSE:To make possible detection of not only load abnormality but also abnormality in the output circuit as the cause of output current abnormality by providing the output current detection circuit on the output side of the invertor circuit in addition to the output side of the AC filter. CONSTITUTION:The current transformers 4a and 4b and the detection circuits 5a and 5b are separately provided to detect the output current on the output side of the AC filter 2 and the inverter circuit 1. When the output current increases in the inverter circuit 1, the current flowing through the current transformer 4b gains but the current of the current transformer 4a does not. On the other hand, when abnormality on the load side increases the load current, the output currents of both the inverter circuit 1 and the AC filter 2 gain. The detection of current of the current transformers 4b and 4a permits the determination of not only the load abnormality but also abnormality in the output circuit side including the inverter transformer 3 and AC filter 2 as a cause of abnormality in the inverter output current. |
