基于小矢量的快速距离保护新算法

衰减的直流分量和非整次谐波对基于线路相量方程的比相式距离保护原理有较大影响。不同于传统上滤除的做法,文中将它们作为有用的电气量和工频量一起构成保护判据。在此基础上为提高保护的动作速度,利用线路的小矢量方程,定义了操作电压小矢量,通过直接比较操作电压和极化电压小矢量相位的方法构成保护判据。EMTP仿真表明,该算法具有不受衰减直流分量和非整次谐波影响的特点,而且对高频暂态量也有很好的抑制作用。

New Phaselet-based Algorithm of Fast Distance Relay

This paper describes a new algorithm of fast distance relay based on the concept of phaselets. The principle is proposed by means of directly comparing phase difference between the operating voltage phaselet and the polarizing phaselet on the basis of new phaselet equation of transmission line and new definition of operating voltage. Additionally, the exponential decaying DC component matches the new phaselet equation. The proposed algorithm, therefore, needs neither converting the phaselets into phasors, nor removing the decaying DC offsets. EMTP simulation tests associated with a simple transmission system and 500 kV transmission system in Shandong power system show that the algorithms are of high speed with simple calculation, not influenced by DC decaying component, and high frequency components are effectively restrained.