一种改进的移相全桥软开关弧焊逆变器

An improved phase-shift full-bridge soft-switching welding inverter

提出一种改进的移相全桥零电压零电流(ZVZCS)弧焊逆变器,其变压器原边串接隔直电容,滞后桥臂串联饱和电抗器.利用输出电感和变压器漏感储能实现超前桥臂零电压开通,隔直电容和漏感的谐振使得滞后桥臂零电流关断,串联的饱和电抗器阻止电流的反向振荡.由于饱和电抗器单向饱和,克服常规ZVZCS变换器饱和电抗器损耗过大的缺点,特别适合在大功率场合.文中还简单讨论了其工作原理和软开关范围.最后制作3kW弧焊逆变器,试验结果验证所提出逆变器的性能.

An improved phase-shift full-bridge zero-voltage zero-current switching (ZVZCS) welding inverter is proposed. By DC block capacitor in series with primary of the transformer, and a saturable inductor in series with the lagging-leg switch, the zero-voltage turn-on for the leading-leg could be achieved due to the energy stored in the output inductor and the leakage inductor, the zero-current turn-off for the lagging-leg could be achieved due to the resonant between the DC block capacitor and the leakage inductor, and the reverse current was blocked by the saturable inductor. Thus, the excessive core losses of the saturable inductor in the conventional ZVZCS converter could be overcome, since the inductor was unidirectional saturable. It was especially suitable for high power applications. The principles of operations and the soft-switching operation range were discussed simply. Finally a 3 kW welding inverter was implemented, and the experimental results were also presented to confirm the validity of the proposed inverter.