适用于电动汽车的SiC MOSFET PSpice仿真模型研究

Study on PSpice Model of SiC MOSFETs Applied in Electric Vehicle

为了基于PSpice电路对电动汽车DC/DC变换器中的碳化硅(SiC)MOSFET的工作特性进行实时准确地仿真,针对SiC MOSFET提出了一种新型的电压控制电流源型VCCST(voltage-controlled current source type)PSpice仿真模型。首先,为了获得SiC MOSFET准确的静态特性建立了电压控制电流源作为SiC MOSFET的内核,以描述SiC MOSFET的转移特性和输出特性;然后,为了获得SiC MOSFET准确的动态特性,建立了基于电压控制电流源与恒定电容的栅漏电容(CGD)子电路模型,所提SiC MOSFET VCCST PSpice模型在简化参数提取方法的同时,能够满足模型准确性的要求;最后,建立的SiC MOSFET VCCST PSpice模型应用于Boost变换器进行仿真和实验,并对SiC MOSFET的特性进行测试。测试结果验证了所提SiC MOSFET VCCST PSpice仿真模型的准确性和实时性,从而为SiC MOSFET在电动汽车DC/DC变换器中的设计和应用提供了便利。

In order to describe the working characteristics of SiC MOSFETs in the electric vehicle DC/DC converters accurately in simulation, a novel voltage-controlled current source type（VCCST） PSpice model is proposed in this paper.First, to obtain good static characteristics curves, a voltage controlled current source is applied as the core of the model which is able to describe transfer characteristics and output characteristics accurately. Then, to obtain good dynamic characteristics curves, the voltage dependency of gate-drain capacitor（CGD） is realized by establishing a sub-circuit containing a voltage-controlled current source and a constant capacitor. SiC MOSFET VCCST PSpice model has the advantage in accuracy as well as simplicity to extract the parameters needed. Simulation and experimental results tested on a Boost converter prove the correctness and effectiveness of SiC MOSFET VCCST PSpice model, thus provides convenience to the electric vehicle DC/DC converter design.