全数字大功率交流脉冲埋弧焊接电源

Digital High-power AC-Pulse Submerged Arc Welding Power Source

为改善埋弧焊的焊接质量,结合脉冲焊接和交流焊接两者优势,提出一种交流脉冲埋弧焊焊接方法,并研制了一台大功率交流脉冲埋弧焊接电源。功率变换电路采用双主电路并联设计,可实现1 250 A交流脉冲电流输出;主电路次级采用耦合电感结构,加快交流过零点速度并提高极性切换时的电弧稳定性;搭建了以STM32F405RGT6芯片为核心的数字化控制系统,通过多特性数字均流策略实现了双主电路的可靠均流和多种电流波形的平稳输出,采用分离式增量PID算法进一步提升动态响应性能。工艺试验结果表明,在同等的焊接条件和交流参数下,交流脉冲埋弧焊比交流方波埋弧焊可获得更深的熔深、更宽的熔宽以及更细化的焊缝晶粒。

In order to improve the welding quality of submerged arc welding, combining the advantages of pulse welding and AC welding, a welding method of AC-Pulse submerged arc welding is proposed, and a high-power AC-Pulse submerged arc welding power source is developed. The power conversion circuit is designed in parallel with two main circuits, which can achieve 1250A AC pulse current output. The secondary circuit adopts coupling inductance structure to accelerate the speed of AC zero-crossing and improve the stability during polarity switching. A digital control system with STM32F405RGT6 chip as the core is built. Through the multi-characteristic digital current sharing strategy, the reliable current sharing of dual main circuits and the stable output of various current waveforms are realized. The discrete incremental PID algorithm is used to improve the dynamic response performance. The process test results show that under the same welding conditions and AC parameters, compared with AC square wave submerged arc welding, AC-Pulse submerged arc welding can obtain larger weld depth and weld width and smaller weld grains.