| This work pertains to the development and application of high-performance IGBTs in high-power soft-switching converters. First, the factors that influence IGBT performance in conventional hard-switching topologies are studied. In particular, device failure mechanisms under high-stress fault conditions are investigated. Gate drive considerations for fault protection are discussed. Second, a new understanding of IGBT charge dynamics under a variety of soft-switching conditions is developed. This understanding is applied to optimize IGBT performance in a series resonant converter (SRC) used in railway traction and electric vehicle battery charger. Experimental data is supported with an understanding of device charge dynamics obtained from finite-element (FE) simulations and analytical calculations. Third, silicon carbide (SiC) diodes are evaluated as a potential replacement of silicon PiN diodes currently used in high-power IGBT modules. The on-state current conduction, defect charge dynamics and switching characteristics are studied in test circuits to demonstrate significant performance advantages of emerging SiC technology for high-power conversion. Compact physics-based circuit models are proposed and validated based on experimental and simulation results that should significantly aid the design of high-performance robust soft-switching IGBT power converters. |
