冲击电压作用下变压器线圈应力分析与研究

摘要

The excessive power transformer coil stress caused by impulse voltage is the main reason for transformer damage. Taking a core power transformer (110/10.5kV, 31500kVA) as an example, to calculate and analyze the leak-age magnetic field and the coil stress when the transformer bears the lightning overvoltage.The distributions of axial, radial and resultant forces as well as the forces on different parts of a winding are obtained based on calculating the axial, radial and resultant forces on inner side, middle part and outside of low and high voltage windings and on inner side and outside of regulating winding by using of finite element method and ANSYS software. So we know the insula-tion margin of low voltage winding is higher than that of high voltage winding and regulating winding. Therefore, the high voltage and regulating winding coils must be inspected at any time and their mechanical strengths must be im-proved also because they are more easily damaged than the low voltage one. Finally, the development tendency is of-fered.%冲击电压作用下变压器线圈应力过大是变压器损坏的主要原因。以一台带铁芯的电力变压器（110/10.5 kV,31500 kVA）为例，对其在雷电冲击过电压作用时的漏磁场和线圈应力等问题进行计算和分析。采用有限元法，使用ANSYS软件进行仿真计算，分别对低压绕组和高压绕组的内侧、中部和外侧与调压绕组的内侧和外侧所受的轴向力、径向力、合力进行计算，得到轴向力、径向力和合力的分布以及对于同一绕组其不同部位的受力情况。从而得出了低压绕组的绝缘裕度要大于高压绕组和调压绕组，高压绕组和调压绕组的线圈应力更有威胁性，绕组更容易受到损坏，应尽可能加强线圈的机械强度并随时检测线圈的损坏情况的结论，并对这一问题未来发展的趋势做出了一些推测。