Silicon carbide (SiC) devices can exhibit simultaneously high electro-thermal conductivity and extremely fast switching. To perform optimal designs showing the benefits of SiC in achieving efficiency, size, weight, and cost objectives for electric converters design, it is necessary to establish better models for calculating device losses and an efficient thermal model that can be calibrated to consider the nuances of measurement based thermal equivalent circuits. This work's outputs can be used in a power converter multi-objective optimization process or real-time temperature prediction of drives to improve reliability and maximize performance. The proposed modified loss calculation and thermal model demonstrate the SiC power module's advantages to reduce peak junction temperature and power cycling effects. A detailed power loss calculation and thermal model is developed and tested on a 480 V, 186 A, 150 HP variable frequency drive (VFD) with SiC modules. A comparison between the SiC module and an equivalent rated Si module demonstrates the reduction in power cycling effects, particularly at low-speed operation. Infrared (IR) imaging results and analytical explanations of the phenomenon is provided. Power cycle tests show that higher thermal conductivity is not the only reason contributing to the lower temperature ripple in low-speed operation.

中文翻译：

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变频驱动器SiC模块的热特性

碳化硅（SiC）器件可同时显示出高的电热导率和极快的切换速度。为了执行优化设计以显示SiC在实现电转换器设计的效率，尺寸，重量和成本目标方面的优势，有必要建立更好的模型来计算器件损耗，并建立有效的热模型进行校准以考虑细微差别。基于测量的热等效电路。这项工作的输出可用于功率转换器多目标优化过程或驱动器的实时温度预测，以提高可靠性并最大化性能。所提出的改进的损耗计算和热模型证明了SiC功率模块在降低峰值结温和功率循环效应方面的优势。在带有SiC模块的480 V，186 A，150 HP变频驱动器（VFD）上开发并测试了详细的功率损耗计算和热模型。SiC模块和等效的Si模块之间的比较表明，功率循环效应的减小，特别是在低速运行时。提供了红外（IR）成像结果和对该现象的分析解释。功率循环测试表明，较高的导热率不是造成低速运行中较低温度纹波的唯一原因。提供了红外（IR）成像结果和对该现象的分析解释。功率循环测试表明，较高的导热率不是造成低速运行中较低温度纹波的唯一原因。提供了红外（IR）成像结果和对该现象的分析解释。功率循环测试表明，较高的导热率不是造成低速运行中较低温度纹波的唯一原因。