This paper proposes a novel, reliable, efficient and cost-effective implementation of partial soft switching in a silicon carbide (SiC)-based variable-frequency phase-modulated resonant transition converter (PMRTC) used in manual metal arc welding (MMAW) applications at a peak power of 1.3 kW. The switching frequency (\(f_{sw}\)) of the converter is increased from 100 kHz at no load to around 150 kHz for a rated power of 1.0 kW. Such an approach is not found in the existing literature. At such frequencies, a significant proportion of the output filter inductance is contributed by the inherent self-inductance of the output “lead cables”. The switching losses in the semiconductor devices are reduced at no-load condition by reduction of the operating frequency. Load regulation is achieved at 150 kHz by implementing phase-shifted PWM technique. Implementation of partial soft switching without using additional components is another significant contribution of this work. The reduced size and weight of the filter inductor in turn reduces the overall size, weight and cost of the system but puts a restriction on the output lead cable length, which is another salient finding of this work. Since at high frequency the transformer model changes, design and finite-element method (FEM)-based simulation of the transformer are also presented in this paper. Loss calculations at 100 and 150 kHz are discussed. The entire converter is fabricated in the laboratory. Experimental and simulated results are found to be in excellent agreement.

本文提出了一种新颖，可靠，高效且经济高效的部分软开关实现方案，该方案是在以下地点用于手动金属电弧焊（MMAW）应用的基于碳化硅（SiC）的变频调相谐振过渡转换器（PMRTC）中实现的峰值功率为1.3 kW。开关频率（\（f_ {sw} \）对于1.0 kW的额定功率，转换器的）从无负载时的100 kHz增加到约150 kHz。在现有文献中没有找到这种方法。在这样的频率下，输出“电感电缆”的固有自感会造成很大一部分输出滤波器电感。通过降低工作频率，可以降低空载条件下半导体器件的开关损耗。通过实施相移PWM技术，可在150 kHz时实现负载调节。在不使用附加组件的情况下实现部分软切换是这项工作的另一个重要贡献。减小的滤波电感器的尺寸和重量继而减小了系统的整体尺寸，重量和成本，但对输出引线电缆的长度造成了限制，这是这项工作的另一个重要发现。由于在高频条件下变压器模型会发生变化，因此本文还介绍了基于有限元方法（FEM）的变压器仿真。讨论了在100和150 kHz时的损耗计算。整个转换器在实验室制造。实验和模拟结果非常吻合。