高频正弦波电流下IGBT能带结构和开关特性分析

Analysis of Energy-band Structure and Switching Characteristics of IGBT Under High Frequency Sinusoidal Current

基于能带理论——载流子浓度分布与电极距离函数的宏观体现,该文提出了一种IGBT在高频正弦波电流及零电流开关条件下开关动态特性的分析方法。首先介绍了功率器件在实际电路中的工作条件,其次提出了IGBT的能带结构图,并通过对独立元件、稳态及暂态时的能带图的分析比较,得出开关动态特性,并给出开关时刻的电压电流初值及能带图;实验结果也验证了IGBT在高频正弦波电流下零电流开关的开关特性;根据这个特性,文章采用随谐振电流大小微调开关频率的方法,来实现功率管电压过冲的完全抑制。

Based on the energy-band which is the macroscopical embodiment of the function between carrier concentration distribution and distance from electrode, the paper presents a methodology to analyze the switching dynamic characteristics of IGBTs under high frequency sinusoidal current and zero-current switching （ZCS） conditions. Firstly, the switching principle of devices which were used in a practical application was given. Then, by analyzing and comparing the energy-band diagrams of IGBTs under the individual state, steady-state and transient-state respectively, there has a common variation tendency during the switching period. Experimental results also validate the switching characteristic of IGBT under ZCS. As a result, this characteristic is used to suppress the switching voltage overshot by changing switching frequency along with the resonant current variety for the power semiconductor devices.