基于驱动电压调节的IGBT结温跟踪管控策略及实现

Tracking control strategy and implementation of IGBTs junction temperature based on gate drive voltage adjustment

针对变流器在运行过程中由于频繁和大范围的随机出力变化,导致IGBT模块内部结温剧烈波动,影响器件运行可靠性的问题,提出并探讨了通过调节栅极驱动开通电压实现功率器件结温平滑跟踪管控策略的思想和具体实现方法。利用一种简化的IGBT损耗分析模型,阐述了驱动电压大小对IGBT损耗的影响,并通过双脉冲实验进行了验证。根据结温变化趋势的大小自动调节驱动电压,在不影响变流器输出性能的同时最大程度减少结温波动,并且具有较快的响应速度。构建了基于一种新型应力测试电路的结温跟踪管控实验平台,实验结果表明,该结温跟踪管控策略具有可行性和有效性,减小了器件承受的热应力冲击。

Due to the variable change of the power output of converters, the IGBTs junction temperature fluctuates violently. In order to reduce this thermal swing and improve the reliability of the IGBTs, a tracking control strategy and concrete implementation for IGBTs junction temperature based on gate drive voltage adjustment are presented and discussed in this paper. Firstly, the influence mechanism of the gate drive voltage on IGBTs power loss is studied with a simpli ed model of the IGBTs for studying switching losses and demonstrated by means of the principle of double-pulse test. The proposed strategy can automatically adjust the gate drive voltage according to the trend of junction temperature, which not only minimizes the junction temperature fluctuation without affecting the converter output capability, but also has a faster response speed. A test platform of tracking control strategy is designed and implemented to employ a novel circuit for power module performance test. Experimental validation demonstrates the effectiveness and feasibility of the proposed tracking control strategy for IGBTs junction temperature, and the thermal swing of IGBT modules is effectively reduced.