【摘要】 为了避免单相故障时自动重合闸装置重合于永久性故障,针对超高压输电线路,首先对单相接地故障时的物理过程进行了分析,紧接着分析了瞬时性故障与永久性故障情况下相电压的特点,然后,从原理上揭示了在二次电弧燃烧阶段两种故障情况下电压信号能量时间分布明显不同。在此基础上提出了利用小波包能谱值来甄别单相故障性质的方法,对采集到的故障相电压信号进行相应的小波包变换,计算相应的能谱值,通过比较能谱值的大小来甄别故障性质。理论分析和基于大量电磁暂态程序EMTP-RV的仿真结果均表明该方法能够较为精准地模拟实际故障,具有较好的实践应用价值。更多还原

【Abstract】 The physical process of the single-phase fault was analyzed on EHV transmission lines so that to avoid reclosing on single-phase permanent fault。then,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。A method,which to make use of the Wavelet Packet Energy Spectrum Value to identify fault types for the single-phase earth fault was proposed。The wavelet packet decomposition of the acquired post-fault voltage signal was performed and the Energy Spectrum Value was extracted and then was compared with Energy Spectrum Value to detect fault types。Theoretical analysis and based on lots of EMTP-RV simulation experiments expatiated that this method can discriminate the type of faults accurately,and has better practicalness and application value。更多还原