变压器局放在线监测的新型降噪法

Research on a New Method of Noise Suppression for On line Partial Discharge Monitor of Transformer

提出并研究了一种抑制变压器局部放电在线监测中电磁干扰的新方法。采用非磁性芯棒罗戈夫斯基线圈电流传感器分别从高压套管及高压套管末屏接地线处耦合信号，利用这两个信号构成定向耦合差动平衡系统，该系统不仅能抑制外部电磁干扰，而且能辨别局放发生的相序。

In this paper, a new method to suppress electromagnetic interference in on line partial discharge monitor of large power transformer is presented and studied. Rogowski coils with nonmagnetic core are employed to couple PD signal respectively from HV bushing and grounding wire of its measuring terminal. Using these two signals, a difference balance system can be formed. This system not only can suppress external interference efficiently, but also can recognize the phase where PD occur in a three phases transformer.