大型换流变压器内绕组辐向屈曲分析

Analysis of radial buckling of inner winding of large power converter transformer

为校核变压器内绕组的稳定性,根据变压器的实际尺寸,应用有限元软件建立变压器的三维模型来计算出内绕组辐向短路电动力。结合实例,建立了变压器内绕组的多弹支模型,以线性屈曲分析理论为基础求得内绕组的辐向屈曲临界载荷值;应用非线性屈曲分析的方法讨论初始缺陷对绕组稳定性的影响,通过仿真求出撑条不同支撑状态时内绕组的位移分布并对其进行对比分析。结果表明,撑条未完全有效支撑或撑条数目不足时会降低内绕组的辐向稳定性。

In order to check the stability of inner winding of power transformer, based on the actual dimension of the transformer, finite element software was used to establish the 3 D model of the transformer and to calculate the radial short - circuit forces. According to the examples, this paper established the multi - span model with spring retainer of inner winding, obtained the radial buckling critical load of inner winding based on the theory of linear buckling. Besides, the theory of nonlinear buckling was used to discuss the influence of the initial geometrical imperfection on the winding stability. The inner winding displacement with different support conditions was obtained through comparison and analysis. The results indicate that the radial stability of inner winding will reduce when the strips are not fully efficient or the quantity is not sufficient.