变压器计及局部安匝不平衡时的轴向动态响应

Axial Dynamic Response Analysis of Transformer with Local Unbalancedampere Turns

基于电磁学及力学理论,运用MagNet仿真软件,针对一台120 MVA/220 k V无励磁调压变压器,建立短路工况下计及安匝不平衡的三维模型,计算绕组线饼所受到的轴向电动力。可以发现绕组受局部安匝不平衡的影响,轴向电动力会在调压绕组端口处产生较大的跃变,且最大轴向电动力出现的位置不再是绕组端部,而在调压绕组端口处。再运用ANSYS软件建立"弹簧-质量-阻尼"模型分析绕组的轴向动态响应,会发现由于最大轴向电动力出现的位置的变化,垫块的最大承受力位置也在变化,最大承受力为11.2 MPa,在许用应力范围内。通过对振动位移的分析可以得到相应变化规律,再通过频谱分析确定绕组固有频率对动态响应的影响,最后对绕组的机械应力及稳定性进行分析。

Based on the theory of electromagnetism and the mechanics theory,it uses the finite element simulation software named Mag Net to establish three-dimensional model considered unbalanced ampere turns to calculate the short-circuit electromagnetic force for a 120 MVA/220 k V without excitation transformer and then get the analysis of axial electric line cake. It can be found by local ampere-turns imbalance,the influence of axial port in regulating winding electric will produce larger distortion. And the position of maximum axial electric appeared no longer is winding ends,but in regulating winding port. Then it analyzes the axial dynamic response by establishing the ＂ Spring-quality-damping＂model. We will find that due to the change of the location of the maximum axialelectric appeared,the maximum tolerance block position is changing and the maximum pressure is 11. 2 MPa. We can get the corresponding variation law by the analysis of vibration displacement. Then determined by winding inherent frequency spectrum analysis of the influence of dynamic response. Finally,the mechanical stress and stability of the winding is analyzed.