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.
出处
《电力自动化设备》
EI
CSCD
北大核心
2010年第2期95-98,112,共5页
Electric Power Automation Equipment
关键词
同杆线路
跨线故障
选相元件
正序平衡点
弱馈
parallel lines
inter-line fault
phase selection element
positive sequence equilibrium point
weak power feeder
