接地距离保护的新型自适应算法

基于单相接地模型计算出线路经过渡电阻接地时由于负荷电流、两侧系统阻抗角不相等引起的附加阻抗,并用来修正传统距离保护的判据,从而得到自适应接地距离保护的动作判据.新判据能准确地计算出线路故障阻抗的电阻分量和电抗分量,使四边形特性距离保护的电阻线和电抗线易于整定,避免下倾的电抗线缩小保护的范围和电阻线的躲负荷性能的复杂分析...

A New Type Adaptive Algorithm of Ground Distance Pretection

Based on the single-phase earthing model, this paper calculates the additional impedance caused by load currents and different impedance angles between two sources when grounded through transition resistance, and revises the criterion of the traditional distance protection by use of it. Accordingly operation criterion of adaptive ground distance protection is obtained. It can compute more accurately the resistance component and reactance component of fault line impedance, which makes resistance line and reactance line of quadrilateral characteristic distance relay easier to set, avoiding shortening protection area because of declining reactance line and avoiding complicate analysis of resistance line dodging load performance. Thereby overreaching and under-reach problems of distance relay are solved. Simulation results prove the proposed adaptive criterion possesses good performance and improves reliability and sensitivity.