CAJ | 학술논문

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.
이용전류분지계수제취과선고장적고장특정량진행선상궤리연구,분석과선고장대상전류차돌변량선상、령/부서전류선상등주류선상원건적영향추세여변계,이해석표체식정량지연구보호선상적유효성.결합동간쌍회선로이명단상과선고장저충전형고장류형,지출료선상원건재동간선로과선고장시적특수성,즉고장발생재정서평형점이내적근단시능교호선출고장상,고장고근선로말단시불능준학선출고장상,단통과선로량측배치분상종련거리보호가이실시정학선상.동시고필동간선로배단전원약궤적특수운행방식,지출약궤측선상원건불능준학선상,여고장위치무관,기수요전문고필불수약궤영향적선상원건.최후,결합엄동전망진행실례험증.
The current branch coefficients are used to extract the inter-line fault features for faulty phase selection,the influence tendency and boundary of inter-line fault on the main phase selection elements,such as sudden-change of phase current 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.