摘要
提出了利用小波包能量熵来判别故障性质的单相自适应重合闸新方法。介绍了小波包能量熵的概念,引入能量修正因子对能量熵定义进行了改进,以获得更高的判别灵敏度。分析对比了2种故障相电压的特点,从原理上揭示了在二次电弧能量较大的频段,2种电压信号能量时间分布明显不同;计算表明2种故障情况下低频节点熵值M3.0比较接近,而在高频段节点处瞬时性故障的熵值要大得多。最后,提出利用高频节点特征频带的熵值均值作为判别指标。理论分析和基于EMTP/Matlab仿真结果表明:该故障判别方法能快速准确地识别故障性质,且灵敏度不受系统运行方式、过渡电阻、故障位置和振荡电压幅值等因素的影响,对二次电弧模型精度要求也不高,具有较好的适应性。
An adaptive reclose criterion is presented for HV transmission lines,which identifies the faults based on energy entropy of wavelet packet. The concept of wavelet packet energy entropy is introduced and improved with the energy correction factor to obtain higher identification sensitivity. The voltage characteristics are compared between transient fault and permanent fault and the fact is revealed that,in principle,the energy time distribution in the bands where the secondary arc energy concentrates is distinctly different. Calculations show that,the entropy M30 is rather close at low-frequency nodes,while the entropies of transient fault are much larger than those of permanent fault at high- frequency nodes. The average energy entropy of character frequency bands at high- frequency nodes is utilized as the fault identification criterion. Theoretical analysis and simulation with EMTP/Matlab show that：it determines fault nature rapidly and accurately,not affected by the system operational manner,transition resistance,fault location and voltage oscillation ,and has better adaptability,the high-precision secondary arc model is not necessary.
出处
《电力自动化设备》
EI
CSCD
北大核心
2009年第9期11-16,共6页
Electric Power Automation Equipment
关键词
小波包
能量熵
高压输电线路
单相自适应重合闸
永久性故障
瞬时性故障
wavelet packet
energy entropy
HV transmission line
single- phase adaptive reclose
permanent fault
transient fault
