冲击电压下CVT传递特性及其缺陷故障检测研究

CVT Voltage Transfer Characteristics Under Impulse Voltage&Its Fault Detection

电容式电压互感器(CVT)内部存在绝缘缺陷时,其整体运行状态不会出现明显变化,但CVT频率响应特性会发生改变。为准确检测出CVT内部的绝缘缺陷,通过获取CVT宽频电压传递函数进行CVT绝缘缺陷故障检测。搭建了冲击电压试验平台,通过雷电冲击、操作冲击和振荡操作冲击3种冲击波形,研究了不同类型冲击电压波形下的CVT频率响应特性。研究结果表明,由3种不同类型冲击电压获取的CVT电压传递函数主要参数特征基本一致,在主电容充电电压相同的情况下,振荡操作冲击电压可以提高输出电压,高效地获取CVT宽频电压传递函数。通过对比不同绝缘缺陷条件下由振荡操作冲击电压获取CVT电压传递函数的差异,为利用冲击电压频率响应特性检测CVT内部绝缘缺陷提供了支撑。

When there are insulation defects inside capacitive voltage transformer(CVT),its overall operating state will not change significantly,but CVT frequency response characteristics will change.In order to accurately detect the insulation defects inside the CVT,broadband voltage transfer function is used to detect the fault of CVT insulation defect.An impulse voltage test platform is built,and CVT frequency response characteristics under different types of impulse voltage waveform are studied through three impulse waveforms:lightning impulse,operation impulse and oscillating operation impulse.The research results show that the main parameters of the CVT voltage transfer function obtained from three different types of impulse voltages are basically same.Under the condition of the same charging voltage of main capacitor,the oscillating operation impulse voltage can increase the output voltage and obtain the CVT broadband voltage transfer function efficiently.The difference of CVT voltage transfer function obtained by oscillating surge voltage is obtained under different insulation defect conditions.The research results provide support for the detection of CVT internal insulation defects by using the impulse voltage frequency response characteristics.