基于温度梯度及统计特性的IGBT模块失效评估方法研究
发布时间：2018-08-06 07:51
【摘要】：随着全球范围内新能源的快速发展,能源转换系统中功率器件的可靠性对电网安全可靠运行的影响日益突出。深入研究功率器件可靠性测试和评估方法,对新能源电力设备及系统的安全评估具有重要意义。温度特性是IGBT模块产品设计和可靠性评估中的重要指标,IGBT模块在不同状态下的温度分布变化规律,常被用来判定其实际状态。根据矢量分析定义,一个标量场的梯度场能更为直接的反映其变化规律。因此论文提出了采用温度梯度及其统计特性的表征功率器件热力学行为的方法。以IGBT模块的电-热-机械应力多物理耦合场模型为基础,研究其不同运行状态下的温度场及其梯度变化特性,提出了利用模块温度梯度及其统计特性来表征IGBT内部失效信息的理论和方法,并建立了IGBT模块的健康状态评估模型。论文以多种典型的IGBT模块为研究对象,搭建了相应的试验平台,利用三维有限元分析、实验结果验证了所提出模型和方法的准确性和有效性。论文的创新性工作包括:(1)建立了计及材料温度敏感性和力学粘塑性的IGBT模块的电-热-机械应力多物理场耦合模型,重点研究了多物理场模型的计算和散热器等效方法,并通过实验验证了模型的准确性。分析了IGBT模块不同失效形式下的温度分布规律,结合功率循环老化实验结果分析了缺陷造成的温度集中和应力集中现象,以及焊料层损伤累积过程。(2)根据IGBT温度场云图的温度连续分布特性以及其统计特性,提出了采用温度梯度及其统计特性表征IGBT模块内部热力行为的方法。分别对不同运行条件以及不同失效形式的IGBT模块的温度梯度以及温度云图的统计特性进行了计算分析。结果表明,温度梯度及其统计特性不仅能够有效反映模块热特性的改变,而且能够用于模块内部缺陷检测。(3)搭建了IGBT模块温度特性试验平台,开展了不同运行工况和老化条件下的IGBT模块温度梯度和温度概率密度分布规律的试验研究,验证了论文所提出方法的准确性。试验结果表明与单一的温度场分析内部状态的方法相比,该方法除了具有更高的灵敏度,还能够有效表征器件整体温度分布差异。此外,通过分析三相全桥IGBT模块不同控制策略下的温度梯度和温度概率密度变化规律进一步验证了方法的准确性和可扩展性。(4)研究了不同运行工作点下IGBT模块的温度梯度和温度概率密度分布规律,通过对不同运行参数作用下的模块温度特性进行数值计算,得到了导通电流I,开关频率fsw和输出频率f等参数对IGBT模块温度特性的影响规律。(5)建立了基于多特征参数的IGBT模块健康状态综合评估模型,并利用BP神经网络实现模块状态的准确评估。结果表明该方法总识别准确率达到93%,可为器件检测提供决策参考;并从热疲劳累积角度建立了考虑老化进程对热参数影响的IGBT模块的失效率计算模型,计算了IGBT模块不同时间尺度热载荷的热寿命消耗。
[Abstract]:With the rapid development of new energy in the world, the influence of power device reliability on the safe and reliable operation of power grid is becoming increasingly prominent. It is of great significance to study the reliability test and evaluation method of power devices, and it is of great significance to the safety assessment of new energy power equipment and system. The temperature characteristic is the design of IGBT module product And the important index of reliability evaluation, the variation of the temperature distribution of the IGBT module in different states is often used to determine its actual state. According to the definition of vector analysis, the gradient field of a scalar field can reflect the law of change more directly. Therefore, the paper presents the power devices using the temperature gradient and its statistical characteristics. The method of thermodynamic behavior. Based on the multi physical coupled field model of IGBT module, the temperature field and its gradient characteristics under different operating conditions are studied. The theory and method of using the temperature gradient of the module and its statistical properties to characterize the internal failure information of IGBT are proposed, and the health of the IGBT module is established. The thesis takes a variety of typical IGBT modules as the research object, builds the corresponding test platform, and uses three-dimensional finite element analysis. The experimental results verify the accuracy and effectiveness of the proposed model and method. The innovative work of the paper includes: (1) the IGBT module which takes into account the temperature sensitivity of the material and the mechanical viscoplasticity is established. The multi physical field coupling model of electric thermal mechanical stress is studied. The calculation of multi physical field model and the equivalent method of radiator are emphatically studied. The accuracy of the model is verified by experiments. The temperature distribution law of the IGBT module under different failure forms is analyzed. The temperature concentration and stress caused by the defect are analyzed by the experimental results of the power cycle aging. Concentration phenomenon and the cumulative damage accumulation process of solder layer. (2) according to the temperature continuous distribution characteristics of IGBT temperature field and its statistical characteristics, a method of using temperature gradient and its statistical characteristics to characterize the internal thermal behavior of the IGBT module is proposed. The temperature gradient of the IGBT modules with different operating conditions and different failure forms, respectively, is presented. The statistical characteristics of the temperature cloud are calculated and analyzed. The results show that the temperature gradient and its statistical characteristics can not only reflect the change of the thermal characteristics of the module, but also can be used to detect the internal defect of the module. (3) the temperature characteristic test platform of the IGBT module is built, and the IGBT module temperature ladder is carried out in different operating conditions and aging conditions. The experimental results of the probability density distribution of the degree and temperature verify the accuracy of the proposed method. The experimental results show that the method can also effectively characterize the whole temperature distribution difference of the device, in addition to a single temperature field analysis method. In addition, the three phase full bridge IGBT mode is analyzed. The variation of temperature gradient and temperature probability density under different control strategies further validates the accuracy and extensibility of the method. (4) the distribution of temperature gradient and temperature probability density distribution of IGBT modules at different operating points is studied, and the numerical calculation is obtained by the numerical calculation of the temperature characteristics of the modules under different operating parameters. The influence of the parameters such as the conduction current I, the switching frequency FSW and the output frequency f on the temperature characteristics of the IGBT module. (5) a comprehensive assessment model of the health state of the IGBT module based on the multiple characteristic parameters is established, and the accurate evaluation of the module state is realized by the BP neural network. The results show that the total recognition accuracy of the method is up to 93%, and it can be used for the device detection. The decision reference is provided, and the calculation model of the failure rate of the IGBT module, which considers the effect of aging process on the thermal parameters, is established from the point of thermal fatigue accumulation, and the thermal life consumption of the IGBT module at different time scales is calculated.
【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN322.8
，
本文编号：2167016
[Abstract]:With the rapid development of new energy in the world, the influence of power device reliability on the safe and reliable operation of power grid is becoming increasingly prominent. It is of great significance to study the reliability test and evaluation method of power devices, and it is of great significance to the safety assessment of new energy power equipment and system. The temperature characteristic is the design of IGBT module product And the important index of reliability evaluation, the variation of the temperature distribution of the IGBT module in different states is often used to determine its actual state. According to the definition of vector analysis, the gradient field of a scalar field can reflect the law of change more directly. Therefore, the paper presents the power devices using the temperature gradient and its statistical characteristics. The method of thermodynamic behavior. Based on the multi physical coupled field model of IGBT module, the temperature field and its gradient characteristics under different operating conditions are studied. The theory and method of using the temperature gradient of the module and its statistical properties to characterize the internal failure information of IGBT are proposed, and the health of the IGBT module is established. The thesis takes a variety of typical IGBT modules as the research object, builds the corresponding test platform, and uses three-dimensional finite element analysis. The experimental results verify the accuracy and effectiveness of the proposed model and method. The innovative work of the paper includes: (1) the IGBT module which takes into account the temperature sensitivity of the material and the mechanical viscoplasticity is established. The multi physical field coupling model of electric thermal mechanical stress is studied. The calculation of multi physical field model and the equivalent method of radiator are emphatically studied. The accuracy of the model is verified by experiments. The temperature distribution law of the IGBT module under different failure forms is analyzed. The temperature concentration and stress caused by the defect are analyzed by the experimental results of the power cycle aging. Concentration phenomenon and the cumulative damage accumulation process of solder layer. (2) according to the temperature continuous distribution characteristics of IGBT temperature field and its statistical characteristics, a method of using temperature gradient and its statistical characteristics to characterize the internal thermal behavior of the IGBT module is proposed. The temperature gradient of the IGBT modules with different operating conditions and different failure forms, respectively, is presented. The statistical characteristics of the temperature cloud are calculated and analyzed. The results show that the temperature gradient and its statistical characteristics can not only reflect the change of the thermal characteristics of the module, but also can be used to detect the internal defect of the module. (3) the temperature characteristic test platform of the IGBT module is built, and the IGBT module temperature ladder is carried out in different operating conditions and aging conditions. The experimental results of the probability density distribution of the degree and temperature verify the accuracy of the proposed method. The experimental results show that the method can also effectively characterize the whole temperature distribution difference of the device, in addition to a single temperature field analysis method. In addition, the three phase full bridge IGBT mode is analyzed. The variation of temperature gradient and temperature probability density under different control strategies further validates the accuracy and extensibility of the method. (4) the distribution of temperature gradient and temperature probability density distribution of IGBT modules at different operating points is studied, and the numerical calculation is obtained by the numerical calculation of the temperature characteristics of the modules under different operating parameters. The influence of the parameters such as the conduction current I, the switching frequency FSW and the output frequency f on the temperature characteristics of the IGBT module. (5) a comprehensive assessment model of the health state of the IGBT module based on the multiple characteristic parameters is established, and the accurate evaluation of the module state is realized by the BP neural network. The results show that the total recognition accuracy of the method is up to 93%, and it can be used for the device detection. The decision reference is provided, and the calculation model of the failure rate of the IGBT module, which considers the effect of aging process on the thermal parameters, is established from the point of thermal fatigue accumulation, and the thermal life consumption of the IGBT module at different time scales is calculated.
【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN322.8
，
本文编号：2167016
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