High precision gate signal timing control based active voltage balancing scheme for series-connected fast switching field-effect transistors
High precision gate signal timing control based active voltage balancing scheme for series-connected fast switching field-effect transistors
复制标题
基于高精度栅极信号时序控制的串联快速开关场效应晶体管有源电压平衡方案
DOI：
10.1109/apec.2018.8341125
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
B. Blalock
中科院分区：
文献类型：
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作者：
Zheyu Zhang;Handong Gui;Jiahao Niu;Ruirui Chen;Fred Wang;L. Tolbert;D. Costinett;B. Blalock
由于高电压高功率应用中的高电压功率器件的低可用性、高成本和有限的性能，通常考虑低压开关的串联连接。实际上，由于动态电压不平衡和由此产生的可靠性问题，串联连接的开关并不流行，特别是对于快速开关场效应晶体管，例如硅（Si）超结MOSFET、碳化硅（SiC）JFET、SiC MOSFET和氮化镓（GaN）HEMT，因为它们的开关性能对栅极控制、电路寄生和器件参数高度敏感。最后，轻微的不匹配可能引入严重的不平衡电压。提出了一种有源电压平衡方案，包括：1）利用微控制器中已有的高分辨率脉宽调制器（HRPWM），在串联开关之间实现精度小于1 ns的可调门极信号定时单元; 2）集成门极驱动作为反馈的在线电压不平衡监测单元。基于最新一代600-V Si CoolMOS的实验结果表明，动态电压可以在很宽的工作条件下自动平衡，更重要的是，所提出的方案没有高速开关的惩罚。
Due to the low availability, high cost, and limited performance of high voltage power devices in high voltage high power applications, series-connection of low voltage switches is commonly considered. Practically, because of the dynamic voltage unbalance and the resultant reliability issue, switches in series-connection are not popular, especially for fast switching field-effect transistors such as silicon (Si) super junction MOSFETs, silicon carbide (SiC) JFETs, SiC MOSFETs, and gallium nitride (GaN) HEMTs, since their switching performance is highly sensitive to gate control, circuit parasitics, and device parameters. In the end, slight mismatch can introduce severe unbalanced voltage. This paper proposes an active voltage balancing scheme, including 1) tunable gate signal timing unit between series-connected switches with < 1 ns precision resolution by utilizing a high resolution pulse-width modulator (HRPWM) which has existed in micro-controllers; and 2) online voltage unbalance monitor unit integrated with the gate drive as the feedback. Based on the latest generation 600-V Si CoolMOS, experimental results show that the dynamic voltage can be automatically well balanced in a wide range of operating conditions, and more importantly, the proposed scheme has no penalty for high-speed switching.