变压器绕组轻微变形ns级脉冲响应分析法

Nanosecond Impulse Response Analysis on Transformers Winding Slight Deformation

ns级脉冲响应分析法能够瞬时测取变压器绕组全频段下的响应特性,为促进它的实际应用,采用波前为5ns、脉宽为50ns的脉冲电压波作为激励信号,通过提高采样频率和采样点数,分频段去噪以获取具有较高频谱上限和精度的脉冲响应曲线。针对频响法对变压器绕组的轻微变形不灵敏的缺点,对5kV温升变压器和500kV电力变压器的高压绕组进行了不同程度的模拟轻微变形实验,并将频响法和ns级脉冲响应分析法的检测结果作了对比。实验结果证明该方法比频响法测试速度更快,精度更高,测取的频谱上限可达数十MHz。具有较高的灵敏度和重复性,能有效检测各种变压器绕组的轻微形变。

Nanosecond impulse response analysis method can instantaneously measure the whole spectrum response of transformer winding,and can obtain the impulse response curve that has higher upper frequency limit and accuracy by using pulse voltage wave which has 5ns＇s waterfront and 50ns＇s pulse width as the excitation signal.Consequently,we experimentally simulated different degrees of slightly deformation on the high voltage winding of 5 kV temperature-rising transformer and 500 kV power transformer in accordance with the characteristics that frequency response analysis is insensitive to transformer winding slightly deformation.Then we compared the results from frequency response analysis and nanosecond impulse response analysis respectively to detect the deformation.Experimental results show that nanosecond impulse response analysis has faster testing speed and higher accuracy than the frequency response analysis,and its upper frequency limit can reach tens of MHz,verifying that the method has higher sensitivity and reproducibility and can effectively detect the slight deformation in different kinds of transformers winding.