反时限距离保护原理的改进

Improvement of the Inverse Time Characteristic of Distance Protection

反时限距离保护是解决近范围快速动作与保护范围末端可靠动作之间矛盾的最好策略。鉴于距离保护动作特性的二维性,目前均采用阶段式开放距离范围的策略达到反时限的效果。提出了一种新型反时限距离保护实现方法,采用相似动作区域的概念,首先根据测量阻抗,确定其所在的二维动作区域边界,根据参考点(一般选择动作原点)将此二维动作区映射为对应的一维同比缩放因子,然后依据此缩放比例因子构造反时限动作方程,由此实现了距离保护的连续反时限动作特性。理论分析表明此方法的合理性,并结合距离保护装置开发实际,给出了具体的实现方案。大量ATP仿真分析表明,此方法可行、有效。

The distance protection with inverse time characteristic is the best choice to solve the conflict between fast trip near the protecting relay and reliable trip at the end of protection zone. Because the distance acting zone presents the characteristic of two-dimensional zone, the policy of trip zone being enlarged step by step has been used to achieve inverse time effect of the distance relay. A novel method about distance relay with inverse time characteristic is presented in this paper, which introduces the idea of similar action zone. And a two-dimensional action zone with the similar figure as the original setting zone is firstly obtained based on the measured impedance, and which is mapped to a one-dimensional zoom factor on the basis of a reference point with the action origin being chosen in general. And then this zoom factor is used to form one action equation with inverse time characteristic. So a distance relay with continuous inverse time action characteristic is realized. The rationality of this method is proved in theory, and one proper project is presented combined with the R＆D practice of distance protection devices. Lots of ATP simulation analysis shows that this method is feasible and effective.