具备应对过负荷能力的距离保护实施方案  

A Scheme to Implement Distance Protection Capable to Cope With Overload

作　　者：周泽昕[1] 柳焕章[2] 王德林 杜丁香[1] 王兴国[1] 

机构地区：[1]中国电力科学研究院,北京市海淀区100192 [2]华中电网有限公司,湖北省武汉市430077 [3]国家电力调度控制中心,北京市西城区100031

出　　处：《电网技术》2014年第11期2948-2954,共7页Power System Technology

基　　金：国家电网公司科技项目(适应大电网运行的继电保护应用策略及协调控制技术深化研究)

摘　　要：介绍了距离保护应对过负荷策略的实施方案,根据过负荷与对称故障、不对称故障、相间故障、单相接地故障的特征分别进行处理。首先利用U1cosφ1识别对称故障与过负荷,利用电流不对称度识别过负荷与不对称故障;然后利用正序功率识别故障点位置,对于相间距离保护,利用相间Uijcosφij(ij=AB,BC,CA)识别相间故障与过负荷,对于接地距离保护,采用相Uicosφi(i=A,B,C)、正序补偿电压与相补偿电压关系识别单相接地与过负荷。利用RTDS建立了仿真模型,模拟了对称过负荷、不对称过负荷及过负荷期间发生故障等不同类型故障,仿真结果表明,本方案过负荷时可靠闭锁距离保护,故障时快速开放距离保护,耐过渡电阻能力高达150Ω。An implementation scheme for the strategy of distance protection to cope with overload is presented,in which based on the features of overload,symmetrical faults,asymmetric fault,phase-to-phase fault and single-phase earth fault those abnormal operation conditions are identified respectively.Firstly,the symmetrical faults and overload are identified by positive-sequence U1cosφ1,then the current unbalance degree is used to distinguish symmetrical faults from overload;in the second step,the fault position is recognized by positive-sequence power,the phase-to-phase faults are distinguished from overload by the criterion Ui jcosφij（ij=AB,BC,CA）,phase characteristics of positive sequence compensated voltage and phase compensated voltage are used to distinguish single-phase-to-ground fault from overload.Based on RTDS a simulation model is established and various types of faults such as symmetrical faults,asymmetrical faults and the faults occurred during the overload period are simulated.Simulation results show that using the proposed scheme the distance protection can be effectively locked under overload and quickly unlocked under faults,besides,the transition resistance that the proposed implementation scheme can endure reaches up to 150Ω.

关 键 词：距离保护 过负荷电流 电压平面 正序功率 正序补偿电压 相补偿电压 Ucosφ 实施方案 

分 类 号：TM773[电气工程—电力系统及自动化]