基于S变换能量相对熵的高压输电线路极性比较式纵联保护  

Polarity Comparison Pilot Protection Based on S-Transform Energy Relative Entropy for High Voltage Transmission Lines

作　　者：李小鹏[1] 何正友[1] 武骁[1] 

机构地区：[1]西南交通大学电气工程学院,四川省成都市610031

出　　处：《电网技术》2014年第8期2250-2256,共7页Power System Technology

基　　金：国家自然科学基金资助项目(51307145);中央高校基本科研业务费专项资金资助项目(SWJTU11ZT07)~~

摘　　要：传统行波极性比较式纵联保护可靠性受小故障初始角等因素影响较大。为提高行波纵联保护的可靠性,在分析线路两端电压和电流极性关系的基础上,提出一种新的极性比较式纵联保护算法。该保护算法利用故障后一段时间内故障电压和故障电流的S变换能量相对熵表征极性关系,进而根据线路两端S变换能量相对熵的比值来识别区内外故障。区内故障时,线路两端电压和电流的能量相对熵相差不大,其比值较小;区外故障时,线路两侧电压和电流能量相对熵差异明显,比值较大。基于PSCAD/EMTDC的仿真结果表明,该保护方案能够快速可靠地确定区内外故障,其性能不受故障初始角、过渡电阻、故障位置、故障类型和母线接线方式的影响。The reliability of the traditional polarity comparison based pilot protection on is greatly influenced by such factors as small fault initial angle and so on. To improve the reliability of traveling wave pilot protection, on the basis of analyzing polarity relationships between voltages and currents at both ends of the transmission line, a new polarity comparison pilot protection algorithm is proposed. In the proposed protection algorithm the polarity relationship is characterized by the S-transform energy relative entropy of fault voltage and fault current within a period of time after the occurrence of the fault, and then according to the ratio of S-transform energy relative entropies at both ends of the transmission line the fault inside the protection zone is distinguished from the fault outside the protection zone. For the fault inside the protection zone the differences of energy relative entropies of voltages and currents at both ends are small; for the fault outside the protection zone the differences of energy relative entropies of voltages and currents at both ends are relatively large because the energy relative entropies at both terminals are quite different. Results of PSCAD/EMTDC based simulation show that the fault inside the protection zone can be rapidly distinguished from the fault outside the protection zone by the proposed protection scheme, and its performance is not affected by fault inception angle,transition resistance, fault position, fault types and busbar connection modes.

关 键 词：纵联保护 极性比较 S变换 能量相对熵 

分 类 号：TM721[电气工程—电力系统及自动化]