考虑老化进程对热参数影响的IGBT模块寿命评估

Lifetime Estimation of IGBT Module Considering Influence of Aging Process on Thermal Parameters

绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)模块是风电转换系统中最为薄弱的环节之一,其准确的寿命和可靠性评估对风电系统安全运行尤其重要。然而,目前IGBT模块寿命评估模型主要采用基于数据手册的瞬态热阻曲线或者试验测试初始结果的热模型,并未考虑IGBT模块老化过程对热参数的影响。该文提出考虑老化进程对热参数影响的IGBT模块寿命评估模型,该模型能够计及老化过程中因热参数增大而带来的热载荷上升和寿命减小,提高了寿命评估的准确性。首先,理论和试验分析了老化进程对热参数的影响规律,提出了考虑老化进程影响的IGBT模块寿命评估模型;其次,对比分析了该模型与现有常用寿命模型之间的差异;最后以实际风电场为例,进一步分析了不同时间尺度下考虑老化影响的模块寿命消耗。

The insulated gate bipolar transistor （IGBT） is one of the weakest components in a wind converter, of which accurate life prediction and reliability assessment are essential to the safety and reliability of wind energy conversion system. However, the thermal resistance is assumed to be kept constant during the whole operation process in commonly used lifetime estimation model, which would overrate IGBT modules＇ lifetime. In this paper, a lifetime estimation model, in which the thermal parameters change and temperature rising caused by thermal resistance increase were taken into account, was proposed, Firstly, theoretical and experimental analyses were done to discuss the effect of thermal resistance increase, and an equal percentage update feedback loop method was adopted to present this effect. Then, comparisons between some existing models and the proposed model were made. Finally, art actual wind energy conversion system is chosen as a case study, the multi-scale lifetime consumption of IGBT module was investigated, in which the influence of aging thermal resistance was considered.