基于波形识别原理的高灵敏度差动保护方法  

A high sensitivity differential protection method based on the principle of waveform recognition

作　　者：张广嘉 刘志远[2] 吴颖超 于晓军[2] 韦鹏[2] 

机构地区：[1]长园深瑞继保自动化有限公司,广东深圳518057 [2]国网宁夏电力公司检修公司,宁夏银川750001

出　　处：《电力系统保护与控制》2014年第22期108-112,共5页Power System Protection and Control

摘　　要：针对风电场中性点经高阻接地系统汇集线母线单相故障时常规母线差动保护灵敏度不足的问题,提出一种基于波形识别原理的高灵敏度差动保护方法。该方法识别故障波形特征,根据负荷情况实时调整浮动门槛值,同时,根据系统谐波含量实时调整差动比率系数,有效避免因谐波引起的高灵敏度差动保护误动作。RTDS的仿真结果表明,该方法能够保证中性点经高阻接地系统在发生单相故障时,迅速切除故障。该方案的应用,对于保护电气设备、维护风电系统稳定运行具有重要意义。When the high resistance neutral point grounded system in wind farm occurs a single-phase fault, the conventional busbar differential protection has sensitivity problem. To avoid this situation, a high sensitivity differential protection based on the principle of waveform recognition is proposed, which identifies fault waveform characteristics, adjusts floating threshold according to real-time load and the differential ratio factor according to harmonic content of the system. The method can effectively avoid malfunction of high sensitivity differential protection caused by harmonic wave. RTDS simulation results show that this method can isolate fault quickly when a single-phase fault occurred in the high resistance neutral point grounded system. The application of the proposed method is of great significance to protecting electrical equipment and maintaining the stable operation of the wind system.

关 键 词：风电场 母线保护 波形识别 差动保护 灵敏度 

分 类 号：TM773[电气工程—电力系统及自动化]