Three Series Voltage Equalization Strategies for Solid-State Switches and Their Comparisons

This paper focuses on the voltage imbalance issue when solid-state switch devices are applied in series, including three types of solid-state switches: MOSFET, IGBT, and TRIAC. By analyzing the causes of static and dynamic voltage imbalance, static voltage balancing circuits and passive RCD dynamic voltage balancing circuits are finally adopted to solve the problem of uneven voltage distribution in series solid-state switches. Through the analysis and calculation of static and dynamic voltage balancing parameters, this paper applies them in the voltage balancing circuits of the three types of solid-state switches in series, thereby achieving a good voltage balancing effect. Finally, through the LTspice simulation software, the voltage balancing circuits of MOSFET, IGBT, and TRIAC in series are respectively built, and the voltage balancing effects before and after adding the voltage balancing circuits are analyzed.