同杆线路跨线故障对选相元件的影响机理  

Influence of inter-line fault on phase selection element for parallel lines on same pole

作　　者：陈桥平[1] 蔡泽祥[1] 刘为雄[2] 曾耿晖[1,3] 肖伟强[1] 

机构地区：[1]华南理工大学电力学院,广东广州510640 [2]广东省电力设计研究院天联公司,广东广州510635 [3]广东省电力调度中心,广东广州510600

出　　处：《电力自动化设备》2010年第2期95-98,112,共5页Electric Power Automation Equipment

摘　　要：利用电流分支系数提取跨线故障的故障特征量进行选相机理研究,分析跨线故障对相电流差突变量选相、零/负序电流选相等主流选相元件的影响趋势与边界,以解析表达式定量地研究保护选相的有效性。结合同杆双回线路异名单相跨线故障这种典型故障类型,指出了选相元件在同杆线路跨线故障时的特殊性,即故障发生在正序平衡点以内的近端时能较好选出故障相,故障靠近线路末端时不能准确选出故障相,但通过线路两侧配置分相纵联距离保护可以实施正确选相。同时考虑同杆线路背端电源弱馈的特殊运行方式,指出弱馈侧选相元件不能准确选相,与故障位置无关,其需要专门考虑不受弱馈影响的选相元件。最后,结合广东电网进行实例验证。The current branch coefficients are used phase selection,the influence tendency and boundary elements, such as sudden-change of phase current to extract the inter-line fault features for faulty of inter-line fault on the main phase selection differential and zero/negative sequence current selection,are analyzed,and the effectiveness of phase selection is researched and expressed quantitatively by analytic expression. For the typical inter-phase fault of double-circuit on same pole,the particularity of its phase selection element is indicated ：the faulty phase can be properly selected when the fault is not located beyond the positive sequence equilibrium point, but it can be properly selected by disposing the phase-splited longitudinal distance protections at both line sides. With the consideration of operation mode,it is also indicated： the phase selection element can not work properly at weak power feeder side ,no matter where the fault occurs,and special phase selection element is needed. The conclusions are verified by the case study of Guangdong power grid.

关 键 词：同杆线路 跨线故障 选相元件 正序平衡点 弱馈 

分 类 号：TM711[电气工程—电力系统及自动化]