摘要
功率器件作为电能变换的核心,准确测量其开关电压可以优化器件的开关行为,评估器件的开关损耗,为功率转换系统的设计提供重要指导。以SiC MOSFET为代表的宽禁带半导体器件具有高速开关特性,传统商用电压探头难以同时满足低侵扰、强抗扰、高带宽与小体积的测量要求,因此提出了一种基于电场耦合原理的同轴圆柱型电压探头。通过感应电极包围引出端的结构降低侵入电容,应用屏蔽覆铜、过孔阵列与屏蔽铜管的强抗扰结构实现对环境噪声的抑制。利用有限元仿真指导了探头参数选取的方案,验证了屏蔽层对噪声的抑制能力,详细分析了同轴探头有效降低侵入性的机理。所设计的同轴探头带宽为280 MHz,量程为-750 V~+750 V,侵入电容约为0.92 pF。最后通过双脉冲实验证明,同轴探头可以准确测量ns级的开关时间,满足SiC MOSFET开关电压的测量需求。
Power devices are the core of electrical power conversion.Accurate measurement of device switching voltage can optimize switching behavior,evaluate switching loss,and provide important guidance for the design of power conversion systems.Wide bandgap semiconductor devices represented by SiC MOSFETs exhibit high-speed switching characteristics,and traditional commercial voltage probes are difficult to meet the measurement requirements of low interference,strong anti-interference,high bandwidth,and small volume simultaneously.Therefore,a coaxial cylindrical voltage probe was proposed based on the principle of electric field coupling.The probe reduces the intrusion capacitance by surrounding the lead end with sensing electrode,and achieves the suppression of ambient noise by applying the strong immunity structure of shielded copper cladding,via array and shielded copper tube.In addition,finite element simulation was used to guide the scheme of probe parameter selection and verify the noise suppression ability of the shielding structure.Moreover,the mechanism by which coaxial probes effectively reduce invasiveness was analyzed in detail from a theoretical perspective.The designed coaxial probe has a bandwidth of 280 MHz,a range of-750 V~+750 V,and an intrusion capacitance of approximately 0.92 pF.Finally,the double-pulse test demonstrates that the coaxial probe can accurately measure the switching time at the ns level,meeting the measurement requirements of SiC MOSFET switching voltage.
作者
白月
康建龙
刘新宇
耿嘉一
石亚飞
辛振
BAI Yue;KANG Jianlong;LIU Xinyu;GENG Jiayi;SHI Yafei;XIN Zhen(State Key Laboratory of Reliability and Intelligence of Electrical Equipment,Hebei University of Technology,Tianjin 300130,China;City University of Hong Kong,Hong Kong 999077,China)
出处
《电机与控制学报》
EI
CSCD
北大核心
2024年第7期77-87,共11页
Electric Machines and Control
基金
河北省自然科学基金(杰出青年科学家基金)(E2021202164)。
关键词
电场耦合
SiC
MOSFET
电压测量
抗扰
侵入电容
electric field coupling
SiC MOSFET
voltage measurement
anti-interference
intrusion capacitance
