Dynamic Waveform-Controlled Ultra-High Frequency Pulse Power System Enabled by SiC MOSFETs: Design and Welding Applications

Conventional pulse power systems (PPS) suffer from inflexible parameter control and limited switching frequencies due to silicon-based devices and fixed modulation designs. This study presents an ultra-high frequency pulse power system (UF-PPS) based on silicon carbide (SiC) MOSFETs and adaptive waveform modulation. The system achieves a switching frequency of 200 kHz through a full-bridge inverter architecture and ARM-based digital control, enabling dynamic adjustments of pulse waveforms, including trapezoidal, sinusoidal, and composite modes, with adjustable amplitude from 50 to 400 A and frequency from 10 to 30 kHz. Experimental results demonstrate enhanced dynamic performance, such as a rise time of 119 μs and fall time of 294 μs, surpassing conventional IGBT-based systems by over 50%. The UF-PPS is validated in advanced tungsten inert gas welding of Inconel 718 superalloy, where increasing the proportion of ultra-high frequency pulse groups reduces the average grain size by 45% from 107.84 μm to 59.03 μm. This innovation provides a versatile solution for high-precision energy control in advanced manufacturing, significantly improving process adaptability and microstructure refinement.