Real-Time Temperature Estimation for Power MOSFETs Considering Thermal Aging Effects
Real-Time Temperature Estimation for Power MOSFETs Considering Thermal Aging Effects
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DOI：
10.1109/tdmr.2013.2292547
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发表时间：
2014-03-01
影响因子：
2
通讯作者：
Cao, Wenping
中科院分区：
文献类型：
--
作者：
Chen, Huifeng;Ji, Bing;Cao, Wenping
本文提出了一种新的实时功率器件温度估计方法，该方法监测功率MOSFET的结温漂移引起的热老化效应，并将更新的功率模块的可编程逻辑器件模型纳入数字控制器。目前，实时估计器正在成为器件结温主动控制以及电力电子系统在线健康监测的重要工具，但其热模型无法解决器件的持续退化问题。由于功率器件层之间的热膨胀系数不匹配，重复的热循环将导致器件组件内的裂纹、空隙甚至分层，特别是在焊料和热油脂层中。因此，功率器件的热阻将增加，使得可以使用热阻（和结温）作为状态监测和控制目的的关键指标。在本文中，通过阈值电压测量预测的器件温度与实时估计的比较，差异是由于老化的设备。数字控制器中的热模型经常更新以校正由热老化效应引起的偏移。三个功率MOSFET的实验结果证实，所提出的方法是有效的，将热老化的影响，在功率器件的温度估计具有良好的精度。所开发的自适应技术可以应用于其他功率器件，如IGBT和SiC MOSFET，并具有显着的经济意义。
This paper presents a novel real-time power-device temperature estimation method that monitors the power MOSFET's junction temperature shift arising from thermal aging effects and incorporates the updated electrothermal models of power modules into digital controllers. Currently, the real-time estimator is emerging as an important tool for active control of device junction temperature as well as online health monitoring for power electronic systems, but its thermal model fails to address the device's ongoing degradation. Because of a mismatch of coefficients of thermal expansion between layers of power devices, repetitive thermal cycling will cause cracks, voids, and even delamination within the device components, particularly in the solder and thermal grease layers. Consequently, the thermal resistance of power devices will increase, making it possible to use thermal resistance (and junction temperature) as key indicators for condition monitoring and control purposes. In this paper, the predicted device temperature via threshold voltage measurements is compared with the real-time estimated ones, and the difference is attributed to the aging of the device. The thermal models in digital controllers are frequently updated to correct the shift caused by thermal aging effects. Experimental results on three power MOSFETs confirm that the proposed methodologies are effective to incorporate the thermal aging effects in the power-device temperature estimator with good accuracy. The developed adaptive technologies can be applied to other power devices such as IGBTs and SiC MOSFETs, and have significant economic implications.