一种基于负荷电流检测的电流互感器饱和识别辅助判据

An assistant criterion for distinguishing current transformer saturation based on the load current detection

电流互感器饱和识别是电流差动保护亟待解决的难题之一。通过分析CT饱和电流特征,指出目前提出的许多饱和识别方法主要是根据饱和电流的某个或多个特征来进行饱和识别的。而负荷电流由于其电流值比较小,肯定不会引起CT饱和,但是当CT流经负荷电流时,有些CT饱和判别方法可能会失效。通过分析负荷电流的特征,从CT肯定不会饱和的角度考虑,提出了一种基于负荷电流检测的抗CT饱和方法,该方法能准确识别负荷电流,而且特征清晰、原理简单,也比较容易实现,可以作为目前提出的CT饱和判别方法的一个辅助判据。

Distinguishing the current transformer saturation is one of difficulties for current differential protection. Therefore, many methods have been proposed to detect CT saturation based on one or more current transformer saturation characteristics, but some may not work reliably when the primary current is the load current, which does not result in current transformer saturation due to its small value. Based on the load current characteristics, a new anti-CT-saturation method for distinguishing load current is put forward in this paper, and it can be used as an assistant criterion for distinguishing current transformer saturation with clear characteristics and simple logic.