| 摘要 |
PROBLEM TO BE SOLVED: To obtain a PWM inverter for reducing size and weight by reducing switching loss and enhancing the frequency at high efficiency. SOLUTION: A resistive semiconductor switching element, having a fast switching speed and resistance characteristics to a current by a voltage drop, is connected in parallel with first, second semiconductor switching elements. In this case, the switching element is turned on preferentially from the first, second switching elements during a period, in which an output current of an AC output current half-period is higher by a prescribed ratio than a peak current. After a switching control signal is given to the first, second switching elements is stopped, the switching elements are stopped after a prescribed period. The first, second switching elements are stopped for a period, in which the output current of the Ac output current half-period is lower by a prescribed ratio than the peak current and is controlled, so that an output is generated by the switching operation of only the resistive semiconductor switching element. |
