Non‐Uniform Voltage Balancing Methods for Series‐Connected SiC MOSFETs in High‐Frequency Fast Switching

• DOI: 10.1049/pel2.70046
• Publication Date: 2025-05-09T07:44:37Z
• Authors: Yixin Shi; Dingmeng Guo; Xiaoning Zhang; Yaogong Wang; Xiaoqin Ma; Rui Fan
• Keywords: Switching frequency

ABSTRACT A half‐bridge circuit formed by series‐connected silicon carbide metal‐oxide‐semiconductor field‐effect transistors (SiC MOSFETs) generates high‐frequency, high‐voltage pulses with a fast rising time, widely used in electro‐optical modulators. Inconsistencies the drive timing, variations device parameters, and parasitic parameters lead to non‐uniform switching behaviour among SiC MOSFETs, causing significant voltage stress disparities potential overvoltage breakdown under severe conditions. The limitations of traditional passive balancing methods are addressed, where reduced speeds increased losses caused identical circuits. novel resistor‐capacitor‐diode (NRCD) voltage‐balancing method is proposed for load side. Considering influence circuit, optimal matching realised calculating capacitance each MOSFET. Experimental results demonstrate that, compared uniform method, NRCD reduces maximum deviation drain‐to‐source voltages from 80.4 V 2.0 pulse rise time 13.0 ns 11.4 at an output 3200 V, representing 10.8% increase speed. At 50 kHz, largest loss devices can be 5.857 W 3.198 W, efficiency improved 45.4%.