Design of a S-TCM 3-Phase Converter with an AGD-Based Control for SiC MOSFETs

This thesis presents the design of a 15 kW three-phase AC/DC converter utilizing Sinusoidal-Triangular Current Mode (S-TCM), which achieves Zero Voltage Switching (ZVS) through Autonomous Gate Drivers (AGDs). These drivers replace conventional solutions, enabling soft switching at all operating points with very high dynamic response. The variable switching frequency introduced by S-TCM spreads the harmonic spectrum, thereby reducing conducted Electromagnetic Interference (EMI) compared to fixed-frequency operation. An analytical model was developed to predict ZVS transitions and determine the LCL filter requirements. Control strategies in the αβ frame were implemented to ensure stable grid current regulation and switching frequency control. Simulations in PLECS validate the design, achieving Power Factor Correction (PFC), four-quadrant operation, and compliant Total Harmonic Distortion (THD).