半桥结构中的SiC MOSFET串扰电压建模研究

With the advantages of low switching loss, high operating frequency and high operating temperature, SiC MOSFET gradually replaces traditional silicon power devices in high efficiency, high power density and high temperature applications. However, the crosstalk problem in gate drive caused by high-speed switch seriously restricts the switching speed of SiC devices. Traditional crosstalk suppression methods focus on the interference voltage introduced by gate-drain parasitic capacitance, which is often reduced by reducing the gate circuit impedance. Based on the switching mode of SiC MOSFET devices, a piecewise linear crosstalk voltage model considering common inductance was proposed. The model was based on the parameters extracted from the device data manual and double-pulse experiment, and considered the influence of non-ideal factors such as gate-drain capacitance, common-source inductance and diode reverse recovery. The results of experiments and models at different voltage points, current points and resistance points were compared. The model shows that the crosstalk voltage is the result of the interaction of gate-drain capacitance, common source inductance and impedance of driving circuit. A single way to reduce the gate circuit impedance has limited effect on the suppression of crosstalk voltage. Based on the proposed model, this paper presented a guidance method for crosstalk voltage suppression, which can be directly used in the design of driving circuit of SiC MOSFET.