A method to analytically calculate the parameters of the fault area between core laminations are proposed and the dynamic trend of the fault development is predicted to comprehensively and accurately obtain the fault degree and damage level of short-circuits between the core laminations of large motors. Considering the influences of frequency and magnetic flux on the axial skin depth of the core and of the eddy current loss on the insulation resistance between the laminations and reviewing the laminations of the stator core tooth as the research object, based on the Maxwell equations and equivalent circuit theory, analytic expressions of active power and induced voltage in the fault area between the laminations are derived; the influence of the number of fault laminations on the electrical parameters in the fault area is quantitatively analyzed; the actual fault development process of the short-circuit faults between the laminations are obtained; and the correctness and effectiveness of the proposed method are verified via numerical simulations and the experiment of faults between core laminations. The sequence of induced voltage changing with the number of fault laminations is selected as the grey sequence to establish the grey prediction model (GM (1,1)). The development curve of the damage depth of the faults between core laminations along the axial direction is illustrated by calculating the sequence data. The results show that the error between the predicted value of the damage depth of the short-circuit fault herein and the experimental value is less than 7%. This method can be used in engineering practices.

中文翻译：

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大型铁心叠片之间的故障计算和轴向损伤深度预测

提出了一种分析计算铁心叠片之间故障区域参数的方法，并预测了故障发展的动态趋势，可以全面，准确地得出大型电机铁心叠片之间的故障程度和短路损伤程度。考虑频率和磁通量对铁心的轴向趋肤深度的影响以及涡流损耗对叠片之间的绝缘电阻的影响，并基于麦克斯韦方程和等效项，以定子铁心齿的叠片为研究对象从电路理论出发，推导了叠层之间故障区域的有功功率和感应电压的解析表达式。定量分析了故障层数对故障区域电学参数的影响。得到叠片间短路故障的实际故障发展过程。通过数值模拟和铁心叠片间断层实验验证了所提方法的正确性和有效性。选择感应电压随故障层数变化的顺序作为灰色顺序，以建立灰色预测模型（GM（1,1））。通过计算序列数据，说明了芯叠片间断层破坏深度沿轴向的发展曲线。结果表明，本文短路故障损伤深度的预测值与实验值之间的误差小于7％。此方法可以在工程实践中使用。