电力系统电缆线故障点信号定位仿真研究

Simulation on Signal Location of Cable Fault Point in Power System

针对电力系统电缆线故障点精确定位问题,因传统检测方法存在对暂态信号难于处理和行波波速不确定性的问题,增加了故障点定位误差。利用小波分析与行波测距结合的定位方法,实现故障波形的db3小波四层分解,并提取高频系数的模极大值序列,将模极大值序列到达检测端的时间与排除波速影响的定位算法结合,更加精确地定位电缆故障位置点。通过Simulink建立电缆故障定位仿真模型对方法进行验证,仿真结果表明,小波分析能够更好地找出故障信号中的奇异点,同时新的定位算法有效地去除了波速的干扰,提高了电缆故障检测精度。

Fauh positioning error is added for the accurate positioning problem of cable fault point in power sys- tem because the traditional detection method has the difficulties in processing transient signals and confirming the traveling wave velocity. Positioning method with wavelet analysis and traveling wave fault positioning is adopted to re- alize the db3 wavelet decomposition of four layers for fault waveform, and then modulus maximum sequence of high frequency coefficient is extracted to position cable fault positioning point more accurately by combining the time from modulus maximum sequence to arrive at detection part and positioning algorithm of excluding the influence of wave velocity together. Simulation model for cable fault positioning is established through Simulink to verify the method. The simulation results show that the wavelet analysis can find out the singular point in fault signal in a better way; at the same time, the new positioning algorithm removes the interference of wave velocity effectively, which improves the cable fault detection accuracy.