Wireless Power Transfer Enabled High-Isolation Gate Driving Technology for WBG Solid-State High-Voltage Pulse-Modulated Switch

Solid-state switch using series-connected wide-bandgap (WBG) semiconductors emerges as a promising solution to improve the performance, lifetime, and reliability of a pulse power supply system. To address the gate driving challenges of the solid-state pulse switch in high-voltage scenarios, this article proposes a wireless power transfer (WPT) enabled high-isolation gate driving technology, in which a two-stage single-input, multiple-output WPT system with series capacitor compensation is proposed with quasi-load-independent constant-voltage (CV) output, powering the driving circuits of series-connected silicon carbide (SiC) MOSFETs. The clearance between the transmitter and receiver of the WPT system provides the feasibility for implementing reliable electrical isolation between the high and low voltage sides, while the fiber optic link transmits the logic control signals. To validate the proposed design, a solid-state high-voltage pulse switch is implemented using five series-connected 1.2-kV SiC MOSFETs and tested under a 3-kV 3-phase LLC converter-based high-voltage platform. The proposed WPT system and the optical fiber optic links, respectively, provide the power and control signal. Experimental results show that the proposed WPT-based gate driving technology is capable of supporting a 2.8-kV 15-μs and 10-kHz high-voltage pulse generation, achieving a voltage imbalance rate of less than 5% with the RCD circuit. Furthermore, the peak efficiency of the overall WPT-based gate driving unit achieve 41.95% at 9.33 W (75.3% for wireless power transfer), validating the effectiveness of the proposed design.