能量法小电流接地选线原理

本文提出了一种小电流接地选线的新原理，利用接地后零序电流和电压构成能量函数，由能量函数的方向和大小判别接地线路。该原理适用于经肖弧线圈接地系统，并且不受负载谐波源和暂态过程的影响，从而面在理论上传统方法选线准确率低的问题。ＥＭＴＰ仿真计算结果表明本文的结论是正确的。本文还对能量法接地选线原理在数字式接地选线装置中的应用进行了研究。

A new principle to detect the grounded line in a neutral point indirectly grounded power system based on the energy function

This paper presents a new principle to detect the ground fault in the neutral point indirectly grounded power system.An energy function consisted by post fault Zero Sequence voltage and current is come up. Thus,according the direction and magnitude of the energy function,the fault line can be detected.The principle is not influenced by load harmonics and the transient process.EMTP simulation results confirmed that the conclusions of this paper is right.The application of the new principle is also discussed in the digital fault line detection scheme.