Temperature‐Dependent Modeling and Validation for Near‐ZCT Transients of High‐Voltage Field‐Stop IGBTs

ABSTRACT The demand for higher power density and cost‐effectiveness in an increasingly competitive market has accelerated the adoption of high‐voltage field‐stop insulated‐gate bipolar transistors (FS IGBTs) in medium‐voltage, medium‐ to high‐power converters. Under near‐zero current turn‐off (near‐ZCT) conditions, the collector‐emitter voltage slope dV CE / dt exhibits a characteristic two‐stage behavior as the space‐charge region (SCR) extends into the field‐stop (FS) layer. However, existing models fail to adequately elucidate the mechanism governing the temperature sensitivity of turning point voltage, which affects the zero‐voltage switching (ZVS) performance of the LLC resonant converter. To address these issues, this article proposes a temperature‐dependent analytical framework for the turn‐off transient. A closed‐form expression for the turning point voltage is derived, establishing a physical criterion for the slope transition. Furthermore, a piecewise dV CE / dt model is formulated, explicitly incorporating temperature effects within the carrier distribution and turn‐off dynamics. The framework is validated through double‐pulse measurements across wide current and temperature ranges. Results demonstrate that the model reproduces the distinct two‐stage slope and turning point behavior with superior accuracy compared to conventional approaches, providing a compact tool for device selection and gate‐driver optimization.