变压器油中局部放电信号超高频特性的研究

Study on ultra-high-frequency characteristics of partial discharge signals in transformer oil

理论分析表明 ,局部放电信号所激发的电磁波具有很宽的频谱 ,它以TEM波的形式向外传播。本文通过实验模拟的方法研究了变压器油中的局部放电脉冲电流波形及其所辐射的电磁波特性 ,实验结果表明 ,变压器油中的局部放电电流脉冲具有极快的上升沿 ,能激励起 1 5GHz以上的超高频电磁波 ,它可以通过超高频传感器加以耦合接收 ,这就为进一步研究超高频检测技术在电力变压器中的应用提供了依据。

Theoretical analysis shows that E\|M waves radiated by discharges in transformer oil have wide band spectrum, and are propagated as transverse E\|M waves. In this paper, an experimental study on PD current pulse and the radiated E\|M waves in oil is done, also these relationships are given. Results show that, PD current pulse in oil has a very short risetime, which is capable of generating ultra\|high\|frequency (UHF) signals at frequencies up to at least 1\^5 GHz, and these E\|M waves can be picked up by UHF sensors. Thus the feasibility of applying UHF partial discharge monitoring techniques to an in\|service oil\|filled power transformer is established.