摘要
准确有效的选相元件是高压输电线路采用自动重合闸的前提。分析了线路发生不同故障情况下电流序分量之间的关系 ,提出了基于电流序分量间相位关系和幅值关系的选相新原理。对于接地故障 ,先利用零、负序电流相位关系判断故障发生在 A,B还是 C区 ,每个区域对应一种单相接地故障和一种两相短路接地故障 ;再用正序电流突变量和负序电流之间的相位关系来确定对应区域内的具体故障相别。该选相元件原理简单 ,相区划分的裕度角大 ,不受系统正序阻抗和负序阻抗不相等的影响 ,并且有很强的耐过渡电阻能力。EMTP仿真结果和动模实验表明 ,该选相元件能有效可靠地选出故障相 。
When adopting the technique of single phase automatic reclosing in EHV/UHV transmission line protection, fault phases should be selected correctly in advance. The relationships among the current sequence components for different faults are analyzed, and an efficient method for determining the fault phases is proposed, which is based on the analysis of phases angle and amplitudes of the current sequence components. When a grounding fault occurs, A, B or C region is judged by the phase angle between the zero sequence and negative sequence components of the current. Each region contains a kind of single phase to ground fault and phase to phase with ground fault; Then the fault phases will be selected by the phases angle between the abrupt discontinuous components of positive sequence and negative sequence components. The principle of the fault selector is simple and the margin of the phase angle is big enough to select the fault phases. The selector proposed has excellent performance under high resistance ground fault conditions. Furthermore, the inequality between the positive sequence and negative sequence impedance of the system has no effect on the selector. In particular, the results of EMTP and physical simulations show that the selector can determine fault phases correctly and meet the requirement of phase selection in real environment. This project is supported by Doctoral Fund of the State Education Ministry of China (No.20010698015).[KH2D]
出处
《电力系统自动化》
EI
CSCD
北大核心
2003年第7期50-54,共5页
Automation of Electric Power Systems
基金
教育部博士学科点基金资助项目 (2 0 0 10 6 980 15 )。
