一种可提高IGBT可靠性的新型结温管控策略

变换器在运行过程中频繁和大范围地随机出力变化,会导致IGBT模块内部结温剧烈波动,使器件持续承受交变的热应力冲击,严重影响器件的可靠性。提出一种通过调节驱动电压实现功率器件结温平滑跟踪和自适应管控的策略。首先,基于简化的IGBT损耗分析模型,阐述了驱动电压大小对IGBT损耗的影响。然后,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抑制结温波动,改善器件周期热应力,提高器件运行可靠性和寿命。最后,通过一种新型应力测试电路的结温跟踪管控实验平台进行实验测试,证明了该结温跟踪管控策略具有可行性和有效性。

A New Junction Temperature Control Strategy Which Improve IGBT Reliability

In order to reduce thermal swing and improve the reliability of the IGBTs,a tracking control strategy for IGBTs junction temperature based on gate drive voltage adjustment were presented. Firstly,the influence mechanism of the gate drive voltage on IGBTs power loss was lucubrated with a simplified model of the IGBTs.The proposed strategy could automatically adjust the gate drive voltage according to the trend of junction temperature,which minimized the junction temperature fluctuation without affecting the converter output capability. A test platform of tracking control strategy was 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.