新型超快变换复合脉冲变极性弧焊电源拓扑

A novel ultrafast-convert complex-pulse variable-polarity arc welding power topology

研究开发了一种超快变换复合高频脉冲方波电流变极性电源的主电路拓扑结构。整体结构分为前后两级,前级两套相互独立的直流电源分别提供基值电流和复合脉冲电流,高频直流脉冲切换电路与后级桥式电流极性变换电路共同将直流电流转换为过零无死区时间并具有多种输出波形形式的复合高频脉冲变极性方波电流,辅助并联吸收保护电路能够保证系统的可靠性和安全性。铝合金TIG焊接试验结果表明,电路可输出具有快速电流上升沿和下降沿变化速率的复合高频脉冲变极性方波电流,可满足高强高效变极性电弧焊接工艺的需要。

A novel main circuit topology of ultrafast-convert complex high-frequency pulse square-wave variable-polarity arc welding power supply was designed and analyzed, which consisted of two parts. In the front part, the base current and pulse current were provided by two independent direct-current power supplies. In the latter part, direct current was transformed into series of high-frequency complex-pulse variable-polarity current, which crosses zero with no dead-time, by high-frequency pulse-forming circuit and full-bridge current-polarity transform circuit. The reliability and safety of the circuit system was effectively provided by assistant parallel-connection protecting circuit. The results of aluminum alloy variable polarity tungsten inert-gas welding show that the high-frequency complex-square-wave variable polarity current generated by novel circuit topology has fast rising and falling edge, which can satisfy the requirements of a novel high-strength and high-efficiency special variable polarity arc welding.