基于瞬时功率理论的输电线路分相电流差动保护  

Split-phase differential current protection based on instantaneous power theory for power transmission line

作　　者：邓翔天[1] 袁荣湘[1] 肖振锋[2] 李体明[1] 李开文[1] 王娅镭 

机构地区：[1]武汉大学电气工程学院,湖北武汉430072 [2]武汉大学动力与机械学院,湖北武汉430072

出　　处：《电力自动化设备》2014年第11期82-88,94,共8页Electric Power Automation Equipment

摘　　要：为了消除分布电容电流对电流差动保护的影响,提出一种基于瞬时功率理论的输电线路分相电流差动保护原理。对线路两端的三相瞬时电流进行傅里叶变换,并对变换后的电流进行低通滤波后得到线路两端的三相基波有功电流分量,利用其构成差动电流保护判据。利用PSCAD软件建立500 k V输电线路仿真模型对所提差动保护原理进行仿真验证,仿真结果表明,其不受过渡电阻和分布电容电流的影响,可快速、准确地区分各种故障类型。A criterion based on the instantaneous power theory is proposed for the differential current protection of power transmission line to suppress the influence of distributed capacitive currents. The three- phase instantaneous currents of two line terminals are processed by the Fourier transformation and filtered by the LPFs（Low-Pass Filters） to extract the three-phase fundamental active-power current components,which is used as the differential current protection criterion. A simulation model of 500 kV power transmission line is built with PSCAD software for verifying the proposed protection criterion and the results show that, immune to the transition resistance and distributed capacitive currents,different fault types can be rapidly and correctly distinguished.

关 键 词：超高压输电 特高压输电 继电保护 分相电流差动保护 瞬时功率理论 单相有功电流 傅里叶变换 仿真 

分 类 号：TM77[电气工程—电力系统及自动化]