电工技术学报2026，Vol.41Issue(10)：3314-3326,13.DOI:10.19595/j.cnki.1000-6753.tces.250978
基于漏源电压脉冲检测的SiC MOSFET短路检测电路
A Short-Circuit Detection Circuit for SiC MOSFET Based on Drain-Source Voltage Pulse Monitoring
摘要
Abstract
The pursuit of lower on-resistance and higher thermal conductivity in SiC MOSFETs,achieved through a reduced chip area compared to comparable silicon(Si)IGBTs,renders them susceptible to intensified electro-thermal stress during short-circuit(SC).Their short-circuit withstand time(SCWT)is limited to 2 μs to 8.5 μs,inversely depending on junction temperature,gate-source voltage(VGS),and drain-source voltage(VDS).Moreover,prolonged SC exposure leads to gate-oxide degradation,a rightward shift in transfer characteristics,and compromised dynamic performance in SiC MOSFETs.However,SC detection methods for SiC MOSFETs based on parameters such as VDS,drain current(ID),the slope of ID(d ID/dt),gate current(IG),power loss,and the slope of VDS(d VDS/dt)often suffer from drawbacks,including difficult parameter setting,limited response speed,package constraints,and circuit complexity.Their practical implementation is heavily dependent on application conditions,often requiring complex,case-specific parameter tuning. This paper proposes a novel SC detection method for SiC MOSFETs based on VDS pulse monitoring.It identifies a hard switching fault(HSF)by monitoring the presence or absence of the negative VDS pulse during the turn-on transient.A fault under load(FUL)is diagnosed by detecting the presence of the positive VDS pulse during the steady conduction period.The parameter tuning for the proposed HSF detection relies on the normal turn-on transient of the SiC MOSFET,ensuring a non-destructive selection of the protection threshold and response time.The FUL detection response time is primarily determined by the VDS rise speed,and a multi-level logic-based judgment effectively prevents false alarms.In practice,the circuit requires no Kelvin-source connection,minimizes the number of integration points with power modules,and exhibits minimal bus-voltage dependence.Furthermore,as the detection circuit shares the same reference potential as the SiC MOSFET to which it is connected in parallel,it eliminates the need for high-voltage isolation or high-bandwidth components,resulting in a low-cost,simple structure.This paper elaborates on the operational principle of the proposed SC detection circuit and presents the methodology for selecting its components.It also analyzes the impact of main circuit parasitic parameters on detection accuracy and reliability. An experimental prototype was fabricated and evaluated on the SC test platform using two types of SiC MOSFETs under different DC bus voltages.The results demonstrate that for a high-current(25 A)device,the circuit achieves response times of 185 ns for a hard-switching fault(HSF)and 178 ns for a fault under load(FUL).When applied to a low-current(7 A)MOSFET,these times are reduced to 82 ns and 64 ns,respectively.Furthermore,tests confirm that the detection response time remains independent of the DC bus voltage within a range from 300 V to 500 V,thereby greatly simplifying parameter tuning in practical applications.Finally,the detection circuit's performance is also validated under a bridge-arm shoot-through fault scenario.The alarm waveforms captured for two series-connected SiC MOSFETs under different SC conditions attest to their suitability for complex fault scenarios.关键词
SiC MOSFET/短路检测/漏源电压/脉冲监测Key words
SiC MOSFET/short-circuit detection/drain-source voltage/pulse monitoring分类
信息技术与安全科学引用本文复制引用
周野,薛征宇,鲜亮,庹玉龙..基于漏源电压脉冲检测的SiC MOSFET短路检测电路[J].电工技术学报,2026,41(10):3314-3326,13.基金项目
中央高校基本科研业务费(3132024108)、中国博士后科学基金(2023M740462)和国家自然科学基金(52471374)资助项目. （3132024108）
