基于参数识别的长输电线路接地距离保护算法  

Grounding Distance Protection Algorithm for Long Transmission Line Based on Parameter Identification

作　　者：索南加乐[1] 王增超[2] 钟应[1] 姚旭[3] 陈新[3] 康小宁[1] 

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]广东电网公司电力调度控制中心,广州510075 [3]甘肃省电力公司电力调度控制中心,兰州730050

出　　处：《高电压技术》2013年第11期2814-2821,共8页High Voltage Engineering

基　　金：国家自然科学基金重点项目(51037005);国家自然科学基金(50877061)~~

摘　　要：针对长输电线路补偿算法采用传统距离保护测距方程后耐过渡电阻能力不强,在保护范围末端发生高阻接地故障时保护容易超越的问题,提出了一种新的基于参数识别的时域长输电线路接地距离保护算法。故障发生后,采用引入插值法的Bergeron模型,利用保护安装处的电压电流来计算线路末端的电压电流,在线路末端应用所推导出的可用于长输电线路分布参数的具有3个系数的时域解微分方程算法来计算故障距离。当计算距离小于保护整定距离时,判为区内故障,保护动作跳闸;否则,保护不动作。理论分析和仿真实验证明,该算法不受长输电线路分布电容和故障暂态的影响,动作速度快,耐过渡电阻能力强,在300km长输电线路、300Ω过渡电阻条件下,保护可靠动作,不会发生超越。The long transmission line compensation algorithm using the traditional distance protection ranging equation will cause overreach when high resistance grounding faults happen in the end of protection domain. To solve this problem, we put forward a grounding distance protection algorithm for long transmission line based on parameter identification in time domain. When faults happen, the algorithm calculates the voltages and currents in the end of the line using the voltages and currents at the relay location, then calculates the fault distance in the end of the transmission line using a new differential equation, which is deduced with three unknown quantities and can be used in the long transmission line of distributing parameter characteristics. When the calculated fault distance is within the protection setting range, the fault happens inside the protection zone and the protection trips. Otherwise, no protection acts. Theoretical analysis and simulation results show that the proposed algorithm avoids the impacts from distribution capacitance current and fault transient signals, and has a high responding speed and high capacity of earth-fault resistance. This protection can trip reliably under 300 ~q earth-fault resistance in 300 km long transmission line without overreach.

关 键 词：输电线路 参数识别 距离保护 过渡电阻 分布参数 补偿算法 

分 类 号：TM773[电气工程—电力系统及自动化]