基于窗口计算法和费希尔判别法的变压器绕组变形诊断新方法

为了提高频率响应分析法检测变压器绕组变形的能力，本文提出了“窗口计算法”对传统的相关系数法进行了改进，并结合费希尔判别法对绕组的故障类型进行诊断。首先，“窗口计算法”是指固定宽度的窗口在频率响应曲线上，以一个固定的频率间隔，从检测的起始频率到终止频率扫过整个检测的频率范围，计算每个窗口中频响指纹的相关系数，获取了绕组变形后频率响应曲线的特征量。最后，利用费希尔判别法对样本数据进行最小化类内散布而最大化类间散布的降维能力，对变压器绕组的变形类型进行了识别。研究结果表明，“窗口计算法”处理后的相关系数法比传统的相关系数法更能反应出绕组变形的程度，有效地解决了传统相关系数法的缺点，结合费希尔判别法能够对绕组的变形类型进行较准确地诊断。

A New Method to Diagnose Winding Deformation in Transformer Based on Windowed Calculation and Fisher Discriminant Analysis

In order to improve the ability of monitor for winding deformation of transformer by frequency response analysis method , windowed calculation was proposed in this paper for improving traditional correlation coefficient method and diagnosed the fault type combined with fisher discriminant analysis. Firstly, a window with specified length is moved from the beginning to the end of frequency band of transfer function and scans the total frequency range of the transfer function with a desired step. At each step, the correlation coefficient are calculated at the window length frequency region and the calculated indices at each step can be used as a feature of frequency response curve after winding deformation. At last, because of the ability of the Fisher Discriminant Analysis for maximizing the between class separability while minimizing their within-class variability, Fisher Discriminant Analysis was utilized for dimension reduction from a lot of calculated features by the proposed method and pattern recognition for winding deformation.