| 摘要 |
PROBLEM TO BE SOLVED: To reduce switching noise and switching loss in an inverter device. SOLUTION: A voltage-type inverter device is operated, so that the relation of output current to output voltage always lags in phase relation, using self-arc- extinguishing semiconductor switching elements Q1 to Q4 such as field-effect transistors. Output current, when the switching elements are arc-extinguished, is detected with a current transformer CT, and an appropriate short circuit preventing period is determined from the current value thereof. The period determined is reflected in switching signals for the elements Q1 to Q4, and thereby switching loss and switching noise are reduced. |
