基于参数识别的时域长线距离保护  

Long Transmission Line Distance Protection Based on Parameter Identification in Time Domain

作　　者：宋国兵[1] 刘林林[1] 索南加乐[1] 袁晓辉[1] 杜斌[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049

出　　处：《电力系统自动化》2009年第18期67-70,81,共5页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50677051;50677061);高等学校博士学科点专项科研基金资助项目(20070698057)~~

摘　　要：对于传统距离保护用于远距离输电时受线路分布电容影响存在暂态超越的问题,给出了一种基于参数识别的时域距离保护新算法。在分布参数线路模型下,根据保护安装处电压、电流计算出保护整定点的电压、电流,再根据微分方程距离保护算法判别区内、区外故障,并利用插值法解决了长线距离保护在低采样频率下无法计算沿线电压、电流分布的问题。仿真结果表明,在特高压长线路末端故障情况下仍能够正确判别区内、区外故障,有效地防止了暂态超越。该方法对采样频率要求不高,不受线路分布电容和非周期分量的影响,提高了长线距离保护的动作可靠性。The traditional distance protections applied to the long transmission line have transient overreach problem caused by influence of line distribution capacitance, so a new time-domain distance protection method with parameter identification is proposed in the paper. With distributed parameter line model, the setting-point voltage and current of the protection are calculated in accordance with voltage and current measured in local terminal, and then distance protection algorithm of differential equation is used to distinguish internal fault from external fault. In addition, using linear interpolation, voltage and current distribution along the line can be calculated by data obtained with a low frequency sampling. Simulation results show that the scheme can distinguish internal fault from external fault correctly and avoid the transient overreach effectively. It needs low sampling frequency and is not affected by line distribution capacitance current and non-periodic component, so the reliability of distance protection is higher than ever.

关 键 词：距离保护 分布参数 线性插值 暂态超越 

分 类 号：TM773[电气工程—电力系统及自动化]