| 摘要 |
<p>When the fact chat an over-current is flowing in the semiconductor devices of power converter (6) is detected by Hall CT (11), abnormality detection unit (9) outputs an abnormality signal. If there is an abnormality signal from abnormality detection unit (9), gate breaking means (13) of gate driving unit (8) outputs a gate breaking signal to stop power converter (6). At the same time, the gate ON means maintains the gate signal of the semiconductor device that has become abnormal in the ON state and, after the current in the semiconductor device has become smaller than a specified value, the gate signal of the semiconductor device is rendered OFF by gate constriction device (12). By this means, the current flowing in the semiconductor device may be reduced prior to the gate breaking operation being performed. <IMAGE></p> |
