This paper presented an improved switching transient model of silicon carbide (SiC)-based asymmetric H-bridge (AHB) power converter for a switched reluctance generator (SRG), which takes the nonlinear phase inductance of the SRG into consideration. First, a systematic mathematic derivation is carried out and the switching transient model is established. Second, the impact of the nonlinear phase inductance of the SRG on switching transients is verified by PSpice & Simulink co-simulations. Third, a power loss model is established by the transient model through PSpice & Simulink co-simulations. The model is conducted to indicate the power loss characteristics of the SiC-based AHB power converter. Simulation results indicate that the nonlinear phase inductance of the SRG is able to accelerate the switching speed of SiC-MOSFETs, and that the SiC converter is advantageous in terms of power loss. Experimental results illustrate that the established power loss model experiences high accuracy. In addition, SiC devices are able to strengthen the power density and efficiency of a converter while reducing its heat dissipation requirements.

本文针对开关磁阻发电机（SRG），提出了一种改进的基于碳化硅（SiC）的非对称H桥（AHB）功率转换器的开关瞬态模型，该模型考虑了SRG的非线性相位电感。首先，进行了系统的数学推导并建立了开关暂态模型。其次，通过PSpice和Simulink联合仿真验证了SRG的非线性相位电感对开关瞬变的影响。第三，通过PSpice和Simulink协同仿真，由瞬态模型建立功率损耗模型。进行该模型以指示基于SiC的AHB功率转换器的功率损耗特性。仿真结果表明，SRG的非线性相位电感能够加快SiC-MOSFET的开关速度，并且SiC转换器在功率损耗方面是有利的。实验结果表明，所建立的功率损耗模型具有较高的精度。此外，SiC器件能够增强转换器的功率密度和效率，同时降低其散热要求。