高功率密度SiC静止无功补偿器强迫风冷散热综合建模及优化设计方法

A Comprehensive Model of Forced Air Cooling and Optimal Design Method of High Power Density SiC-Static Var Generator

为了提高大功率高功率密度电力电子装置热设计的准确性和设计效率,该文综合热传导、对流换热与流体力学理论,针对电力电子装置的典型强迫风冷散热系统,提出基于截面积二次方根为无量纲特征长度的综合热模型,并提出一种强迫风冷散热系统体积最优的优化设计方法。以380V/50kvar高功率密度静止无功补偿器(SVG)为例,比较所提出的综合热模型与温升实验的热阻,综合热模型平均热阻误差在7%以内,即在SVG满载运行时,散热器平均表面温升的绝对误差ΔTe在1.3℃以内。该文提出的综合热模型相对于传统热模型精度提升62%,证明了综合热模型的准确性。基于所提出的优化方法设计的散热系统体积4.03L,对比传统方法设计的体积5.7L,体积缩小30%,从而证明了该文提出优化设计方法的可行性。

Base on a novel characteristic length scale(the square root of cross-sectional),a comprehensive thermal model for the typical forced air cooling system of power electronic devices was proposed integrating heat conduction,convection heat transfer and fluid mechanics theories.In order to improve the accuracy and efficiency of the thermal design,an optimized design method for the optimal volume was proposed for the high-power and high-density power electronic device.Taking a 380V/50kvar high power density static var generator(SVG)as an example,compared with the experimental results,the average thermal resistance error of the comprehensive thermal model is within 7%,that is,the corresponding surface temperature rise is within 1.3℃when SVG is running at full load.The accuracy of the comprehensive thermal model is improved by 62%compared with the traditional thermal models.Consenquently,the demention volume of the cooling part designed based on the proposed method is 4.03L,which is 30%smaller than the volume of 5.7L designed by the traditional methods.