摘要 |
In an inverter device, a first three-level circuit includes first to fourth preceding-stage switch elements connected in series between a first input end and a ground and a first charging and discharging capacitor. A second three-level circuit includes fifth to eighth preceding-stage switch elements connected in series between a second input end and the ground and a second charging and discharging capacitor. The first and second two three-level circuits define a five-level circuit that is subjected to switching with the carrier frequency of PWM modulation. The output polarity of a subsequent-stage bridge clamping circuit is inverted between the anterior half cycle and the posterior half cycle of a power supply frequency. |