变压器绕组的陡波电压分布特性

Steep-front Impulse Voltage Distribution Characteristics of Transformer Windings

为得到高频陡波如雷电波、快速暂态过电压进入变压器高压绕组后的变化规律,利用波头时间分别为1200、200、60 ns,输出电压为1 000 V的陡波发生装置,实际测量模拟变压器绕组各出线端头的电压波形,绘制高压绕组峰值和瞬态电压分布图,研究和分析其分布特性及其影响因素。结果表明:波头时间越短变压器绕组的电压分布越不均匀;快速暂态过电压比雷电波对变压器绕组首端位置主绝缘和纵绝缘的危害大。

It is important to ohtain the variation rules of transformer＇s high voltage windings when steep-front impulse voltage with high frequency such as lightning overvoltage and very fast transient overvohage enters the windings. Through 1000V voltage with time to peak is 1.2μs,200ns and 60ns produced by steel〉front impulse voltage generators, the voltage waveform of each end windings in simulative transformer is measured, the peak and transient voltage distribution of high voltage windings is mapped, the peak and transient vohage distribution and its influencing factors is studied. It is concluded that voltage distribution charaeteristics of transformer windings are much uneven as time to peak is much shorter. The hazards of major insulation and minor insulation on head point of transformer windings eaused by very fast transient overvoltage are much more than that caused by lightning overvoltage.