基于电场耦合原理的SiC MOSFET开关电压感知探头
SiC MOSFET switching voltage sensing probe based on electric field coupling principle
白月 1康建龙 1刘新宇 1耿嘉一 2石亚飞 1辛振1
作者信息
- 1. 河北工业大学 省部共建电工装备可靠性与智能化国家重点实验室,天津300130
- 2. 香港城市大学,香港999077
- 折叠
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.
Abstract
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 guid-ance 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 dif-ficult to meet the measurement requirements of low interference,strong anti-interference,high band-width,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 sur-rounding 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 addi-tion,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 ef-fectively 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 ap-proximately 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 switc-hing voltage.
关键词
电场耦合/SiC/MOSFET/电压测量/抗扰/侵入电容Key words
electric field coupling/SiC MOSFET/voltage measurement/anti-interference/intrusion capacitance引用本文复制引用
基金项目
河北省自然科学基金(杰出青年科学家基金)(E2021202164)
出版年
2024
NETL
NSTL
万方数据