电工技术学报2025，Vol.40Issue(16)：5013-5028,16.DOI:10.19595/j.cnki.1000-6753.tces.241066
基于器件物理的高压SiC MOSFET短路故障行为模型
Behavior Model of High-Voltage SiC MOSFET's Short-Circuit Fault Based on Device Physics
摘要
Abstract
The short-circuit ruggedness of silicon carbide(SiC)MOSFETs represents a significant challenge that impedes their widespread adoption in high-voltage applications.Developing effective short-circuit protection strategies in domestic high-voltage SiC MOSFETs is hampered by a lack of robust technical expertise and empirical experience.Furthermore,the absence of fast and accurate simulation models presents a fundamental obstacle to advancing research on the application of domestic high-voltage SiC MOSFETs.Traditional behavioral models focus on fitting these devices'static and dynamic characteristics but fail to simulate fault conditions adequately.Recently,several models have been proposed for short-circuit scenarios.However,these models exhibit limitations,including low adaptability for high-voltage devices,insufficient universality,and inefficient parameter extraction.This paper introduces a behavioral model for high-voltage SiC MOSFETs,which incorporates practical physical characteristics.The proposed model can accurately simulate the device's behavior-such as voltage and current dynamics-throughout a short-circuit fault event. The behavioral model comprises five primary components:a controlled current source(ICH)for calculating the current flowing through the channel,a controlled current source(ILEAK)for assessing the leakage current under high junction temperature conditions,a diode(D)representing the device's body diode,capacitors(CGS,CGD and CDS)for the junction capacitances,and a resistor(RD)denoting the total resistance of the drift layer and JFET region of the device.In high-voltage devices,the resistances associated with the drift layer and JFET region constitute a significantly large proportion of the total on-resistance compared to devices rated below 1.2 kV.The increased resistance markedly influences the device's behavior during short-circuit faults.Consequently,RD is carefully calculated based on the practical structure of high-voltage SiC MOSFETs and the current path during short-circuit events at the cell level.The model's parameters are categorized into four types,each with detailed extraction methods.Furthermore,key physical parameters that are challenging to measure-such as intrinsic carrier concentration(ni),threshold voltage(VT),and carrier mobility(μ)-are calculated based on semiconductor physics principles.The strong physical significance of the model's components and the parameters enhances the universality and portability of the proposed model. A 6.5 kV/400 A SiC MOSFET produced by the State Grid Smart Grid Research Institute Co.Ltd is modeled.The model is developed,and short-circuit test simulations are conducted using Matlab/Simulink.A short-circuit test experimental platform is established for the selected device.Short-circuit tests are performed under a short-circuit duration(tSC)of 2.5 μs and DC-bus voltages(VDC)of 3 300 V and 2 470 V.The high consistency between the simulated and experimental waveforms indicates that the presented model effectively simulates the behavior of high-voltage SiC MOSFETs during short-circuit faults.The relative errors of the current rise rate and peak short-circuit current are less than 2.20%and 0.83%.Additionally,the relative errors of simulated peak currents with the low-voltage models are 7.58%and 5.89%under VDC=3 300 V and VDC=2 470 V,respectively,seven times those with the proposed model.关键词
碳化硅MOSFET/高压功率器件/行为模型/短路故障/参数提取Key words
Silicon carbide(SiC)MOSFET/high-voltage power devices/behavior model/short-circuit fault/parameter extraction分类
信息技术与安全科学引用本文复制引用
巫以凡,李驰,徐云飞,郑泽东,郝一..基于器件物理的高压SiC MOSFET短路故障行为模型[J].电工技术学报,2025,40(16):5013-5028,16.基金项目
国家电网有限公司科技资助项目(SGSNKY00KJJS2100291). （SGSNKY00KJJS2100291）
