软开关弧焊逆变电源外特性的理论分析

通过分析移相全桥软开关弧焊电源工作特性,提出了基于峰值电流反馈控制软开关弧焊电源拓扑结构,运用电路分析方法把全桥弧焊电源等效为Buck模型,在不同负载条件下,Buck模型分别工作于电感电流连续方式和电感电流断续方式,运用电路知识对移相全桥零电压脉宽调制器稳态运行单周期波形图参数进行了理论计算,对模型的外特性工作点边界进行详细分析,通过分析计算证明了弧焊电源外特性形成机理,并给出一种所需外特性的实现电路.结果表明,软开关弧焊电源外特性边界曲线直接决定了焊接工艺参数的调节范围,通过不同的控制策略可以实现弧焊电源的所需外特性.

Theoretical analysis for output characteristics of soft-switching arc welding inverter

Through the analysis of phase-shifted soft-switching full-bridge power converter characteristics,a soft-switching arc welding power system topology of peak-current mode control is proposed.The full-bridge model of arc welding power is equated to Buck model using small-signal analysis method.Buck model works in continuous conduction mode or discontinuous conduction mode under different load conditions.Based on circuit theory,the boundary points of static characteristics in one PWM working process cycle of phase-shifted full-bridge zero-voltage-switch are analyzed with theoretical derivation.The adjustment range of welding parameters is directly determined by the boundary curves of arc welding power output characteristics.Thus,it can achieve the required output characteristics of arc welding power source by using different control strategies.