Design of a High-Voltage, High-Frequency Solid-State Switch Using Series-Connected SiC MOSFETs and a GaN HEMT-Based Transformer-Coupled Gate Driver for Dielectric Insulation Testing of a Renewables-Rich Future Energy Grid

Abstract

The increasing integration of renewable and distributed energy sources is introducing complex, highfrequency, high-voltage waveforms that can stress and damage grid dielectric insulation systems. This work presents a scalable solid-state switch architecture using series-connected SiC MOSFETs driven by a GaN HEMT-based transformer-coupled gate driver, enabling flexible, precise, and high-frequency highvoltage waveform generation for dielectric insulation testing in future power-electronics-dominated grids. The system leverages series-connected SiC MOSFETs to extend voltage capability while maintaining wide-bandgap efficiency, and a GaN-based gate driver to achieve fast, synchronized switching across the stack. Analytical modeling, simulations, and prototype testing demonstrate that GaN based transformer coupled gate driver provides faster rise/fall times, improved voltage sharing, and enhanced waveform control, while higher transformer frequency reduces core size and improves switching synchronization. The proposed approach offers high isolation, fast switching, and stable voltage sharing, enabling compact, reliable generation of complex high-voltage, high-frequency waveforms for advanced insulation testing in renewable-rich electrical grids.