基于单端单回线电气量的同杆双回线单相接地距离保护  

Single-phase Grounding Distance Protection of Parallel Transmission Lines on Same Poles Based on Electric Quantities Data from Single Terminal and Single Line

作　　者：毕天姝 李伟 徐振宇 杨奇逊 

机构地区：[1]新能源电力系统国家重点实验室、华北电力大学,北京市102206

出　　处：《电力系统自动化》2013年第7期88-93,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金重大国际合作项目(50920105705);国家自然科学基金重点项目(50837002);国家重点基础研究发展计划(973计划)资助项目(2009CB219704);高等学校学科创新引智计划(“111”计划)资助项目(B08013);北京市教育委员会共建项目~~

摘　　要：基于单端单回线电气量的传统距离保护直接应用于同杆双回线时,受零序互感的影响,其测距精度难以满足要求。文中提出了一种仅采用单端单回线电气量的单相接地距离保护新算法,它可以考虑相邻线路零序互感的影响,实现准确测距。通过分析同杆双回线单相接地故障模型,推导出了含有双回线零序电流的故障距离准确表达式;进一步分析了双回线零序电流之间的关系式,代入故障位置估算值后,可以将邻线零序电流用保护安装处零序电流表达出来,实现了由单端单回线电气量对双回线零序电流的计算,进而实现了所提出的距离保护方法。经PSCAD仿真验证,提出的算法对故障位置估算值的精度不敏感,且对系统运行工况具有较好的适应性,提高了同杆双回线单相接地故障时测量阻抗的精度。The distance-measuring accuracy of conventional distance protection based on one-end sampling data from single line is difficult to satisfy specification requirement for parallel lines on same poles（PLSP）affected by zero-sequence mutual inductance between the lines.Using one-end sampling data from single line,a new algorithm for distance protection of single-phase grounding fault of parallel transmission lines,which can consider the effect of zero-sequence mutual inductance of adjacent lines is proposed.It achieves accurate distance-measuring.Through analyzing fault model of single-phase grounding fault of PLSP,the fault distance accurate expression with zero-sequence currents of parallel lines is derived.Further,the expression between zero-sequence current of the adjacent parallel line is analyzed.By substituting the estimate value of fault location,zero-sequence current of neighbor line can be represented by zero-sequence currents of the protection site so as to calculate zero-sequence current of PLSP with one-end sampling data from single line.Finally,an accurate fault impedance can be calculated by one-end sampling data from single line with consideration of the impact of mutual coupling effect.Simulation results with PSCAD show that the algorithm is insensitive to the accuracy of estimated fault location and has good adaptation capability for system operation.It can increase impedance-measuring accuracy of single phase grounding fault for PLSP.

关 键 词：同杆双回线 距离保护 单相接地故障 过渡电阻 

分 类 号：TM773[电气工程—电力系统及自动化]