大功率GTO等效传热模型的研究

INVESTIGATION ON THE EQUIVALENT HEAT TRANSFER MODEL OF LARGE CAPACITY GTO

研究发现ＧＴＯ 动态热阻变化率的对数具有分区间近似线性的规律，提出可采用分段拟合的方法初步获得ＧＴＯ的高阶传热模型。基于最速下降原理构造了一种迭代算法，可以精确整定等效传热模型的各个参数，并研究了下降因子对迭代收敛性的影响。与ＧＴＯ 的实测动态热阻曲线比较，该模型的计算误差在±３％ 以内。将此传热模型集成在损耗分析软件中，可分析ＧＴＯ的瞬态传热特性。

Through investigation it is found the logarithm of varying gradients of GTO's dynamic thermal resistance shows approximate linear behavior with respect to different time intervals, and a strategy of multipartite fitting by LMS (Least Mean Square) method is presented to acquire the preliminary parameters of GTO's high order heat transfer model. Based on the Steepest Descent Theory an iteration algorithm is designed to adjust each parameter of the heat transfer model with high accuracy, and the influence of descent rate μ on the iteration convergence is also investigated. Compared with GTO's dynamic thermal resistance curve by experiments, the maximum calculation error of the model presents no more than ±3%. Integrated in the Power Loss Analysis Software, the model can be used to analyze GTO's transient thermal characteristics, and calculation examples show the model is effective.