高频正弦波电流下IGBT能带结构和开关特性分析

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。

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

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.