Analysis and Research on the Current Sharing Characteristics of Paralleled IGBTs in Low-Voltage Solid-State Circuit Breakers

With the rapid development of low-voltage DC (LVDC) distribution systems, Solid-State Circuit Breaker (SSCB) has gradually become key protective devices due to their fast interruption speed and high reliability. In SSCBs, power switching devices such as IGBT and MOSFET are connected in series and parallel to form the main power switching module that controls circuit conduction and interruption. However, current imbalance during the paralleling of power devices can easily lead to device failure, which limits the large-scale application of SSCBs. This paper focuses on the current-sharing characteristics of paralleled IGBT in low-voltage solid-state DC interruption, and systematically investigates the key influencing factors and their mechanisms affecting current distribution. A circuit simulation model is built based on LTspice, and the correctness of the theoretical analysis is verified through simulation. The research results provide a theoretical basis for studies on current sharing of paralleled IGBT and offer guidance and reference for the design and interruption capability enhancement of low-voltage SSCBs.