频率响应法对变压器绕组变形的测试与分析

电力变压器在运输中受冲撞或在运行中不可避免地遭受各种故障短路电流的冲击。变压器出口附近一旦发生短路故障,变压器绕组将承受巨大的、不均匀的轴向和径向电动应力作用。如果绕组内部机械结构存在薄弱环节,承受不住电动力的冲击,变压器线圈必然会产生绕组扭曲、鼓包或移位等变形现象,严重时甚至导致线圈突发性损坏事故。频率响应法利用扫频技术,通过测试变压器绕组频率响应特性曲线进行横向或纵向比较,可准确诊断变压器绕组变形情况,因此得到广泛应用。

Power transformers during transportation by the collision or in the operation of various failures inevitably suffer the impact of shortcircuit current. Transformer short-cireuit fault near the exit event of a transformer winding will be under huge, non-uniform axial and radial electric stress. If the winding weaknesses in the internal mechanical structure to withstand the impact of electric power, transformer coil windings will inevitably produce distortions such as deformation or displacement of bulge phenomenon, or even lead to serious damage to the coil of sudden accidents, frequency response methods using the sweep technique, by testing the frequency response characteristics of transformer winding horizontal or vertical curves compared with the accurate diagnosis of transformer winding deformation, so widely used.