用结构参数法研究变压器绕组变形判据

为准确判断变压器在短路后的绕组变形情况,对频率响应法的测试和判定标准进行了研究。采用变压器绕组等效电路模型,研究绕组承受出口短路电动力作用、发生变形后电路特性的变化。提出了研究绕组变形的结构参数法。针对变压器绕组发生不同形式和程度变形后的结构变异,进行等效电路参数变化的分析,计算由此引起的变压器绕组频响谱线的变化,用谱线的均差方根值作为判断绕组变形程度的依据,给出测试和判断标准,并且得到了一些现场实例的验证。

Criterion for transformer winding deformation calculated by the structural parameter method

The deformation of transformer windings after a short circuit was analyzed by studying the criterion for the frequency response. The equivalent circuit of a transformer winding was used to study the change of the winding's electrical characteristics after the deformation caused by the electrodynamic stress. The structural parameter method was used to study the winding deformation. The changes of the winding structure after the deformation due to the short circuit were related to changes of the parameters for the equivalent circuit. The frequency response of the deformed winding was then calculated, with the degree of winding deformation judged by the mean square root of the spectrum difference. A testing criterion has been validated by examples from field experiments.