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

A new method of winding deformation diagnosis in transformer based on windowed calculation and Fisher discriminant analysis

为了提高频率响应分析法检测变压器绕组变形的能力,文中提出了"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,扫过整个检测频段,计算每个窗口中频响曲线的相关系数,获取了绕组变形前后的特征量。最后,利用费希尔判别法对样本数据进行降维的能力,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"改进后的相关系数法比传统的相关系数法更为准确地诊断出绕组的变形程度,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较准确地诊断绕组的变形类型。

In order to improve the detection ability for winding deformation of transformer by frequency response analy-sis method, the windowed calculation method was proposed in this paper for improving traditional correlation coeffi-cient method and diagnosing the fault type combined with fisher discriminant analysis. Firstly,a window with specified length scans the total frequency range of the transfer function with a desired step. At each step,the correlation coeffi-cients are calculated at every window and the calculated indices at each step can be used as a feature before and after winding deformation. At last, because of the ability of reducing dimension, Fisher discriminant analysis was utilized for pattern recognition for the type of winding deformation. The results in this paper showed that correlation coefficient method improved by windowed calculation was more accurate to diagnose the degree of winding deformation than tradi-tional correlation coefficient method, which effectively solved the shortcomings of traditional correlation coefficient method and can accurately diagnosed the type of winding deformation after combined with fisher discriminant analysis.