一种峰值电流控制的全桥软开关弧焊逆变器

Full-bridge soft-switching arc welding inverter based on peak current control

提出一种峰值电流控制的移相全桥软开关弧焊逆变器,该逆变器的变压器初级串联隔直电容,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,饱和电抗器阻止电流的反向振荡,次级电路采用倍流整流方式,整流二极管实现自然换流.变压器次级无需中心抽头,只承担输出电流的一半,输出电感采用同一磁芯绕制,利用峰值电流控制方式获得恒流外特性.文中还讨论了其工作原理.最后制作2.5 kW弧焊逆变器,并给出相应的试验结果.

A phase-shift soft-switching full-bridge welding inverter is proposed based on peak current control.By a DC block capacitor in series with the primary of transformer,and a saturable inductor in series with the lagging-leg switch,the zero-voltage turn-on for the leading-leg can be achieved due to the energy stored in the output inductor and the leakage inductor,the zero-current turn-off for the lagging-leg can be achieved due to the resonance between the DC block capacitor and the leakage inductor,and the reverse current is blocked by the saturable inductor,the diodes in the secondary circuit can be turned off naturally due to the current doubler rectifier.Hence,the center-tap in the transformer is not needed,and only half of the output current is carried by the secondary winding of the transformer,and the output inductor can be integrated on a single core,the external characteristics of constant current is obtained by peak current control mode.The principle of operations was also discussed.Finally,a 2.5 kW arc welding inverter was made,and the relevant experimental results were also presented.