摘要
故障后由于分布电容引起的高频分量在频域表现为固有频率主频的谐波形式,分析了影响固有频率的各种因素,提出了一种基于固有频率的超高压输电线路故障选相新方法。该方法采集输电线路单侧故障后电流,通过模量变换获取模分量,利用多信号分类(MUSIC)算法求取模电流频谱,利用频谱特征进行故障类型识别,确定故障相。理论分析表明,故障后的各种频率信号中,除了工频信号以外,固有频率信号是明确的,且信号较强,便于采集。与传统选相方法相比,该方案可以准确、快速地识别故障类型,确定故障相别,且不受系统振荡、负荷电流、故障时刻和系统运行方式的影响,受TA饱和的影响较小。仿真分析验证了该方法的灵敏性和可靠性。
The periodic current and voltage in transient component are caused by electromagnetic wave flowing through the transmission line and reflecting between fault location and source impendence. In frequency domain the current spectrum is a series of harmonic of a frequency catted nature frequency. The nature frequency is related with the length from fault location to source. A protection scheme based on nature frequencies is proposed in this paper,various impact factors of nature frequencies also are discussed. The currents in one ends of line are sampled av.d transformed model component, the current spectrums are computed by multiple signal classification algorithm （MUSIC}, nature frequencies of modal current are used to identify fault types and fault phase. The nature frequencies exist in fault component besides power frequency, the energy is strong and th.ey are easy to sample. Compare to conventional protection, the scheme proposed needs less time to identify fault types. It works quickly and is immune to TA saturation, system oscillation, load current, mode of operation and transient resistance, it can identify fault types, internal faults from external faults in various fault time and fault location accurately. The performance of scheme is investigated for various faults on ATP simulated transmission feeder.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2009年第6期1502-1508,共7页
High Voltage Engineering
关键词
电力系统
继电保护
固有频率
频谱分析
故障选相
故障类型
多信号分类算法
power system
relaying protection
nature frequency
spectrum analysis
fault phase selection
fault type
multiple signal classification （ MUSICI algorithm
