【作者】 陈靖；

【导师】 张承学；

【作者基本信息】 武汉大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 输电线路发生故障后，不仅影响工农业生产和人们的日常生活，而且还危及电力系统的安全、稳定运行。准确、可靠的故障测距，不仅可以缩短查找故障的时间，使故障得以及早处理，保证迅速恢复供电，而且还能及早发现输电线路的薄弱环节，有效地降低因停电造成的经济损失。因此，精确的故障测距具有极大的社会效益和经济效益，是一项具有重大技术、经济意义的研究课题。 故障后的行波信号是一个突变的、具有奇异性的信号。小波变换所具有的时频局部化特性使其非常适合于对这种信号的分析。本文讨论了小波变换及小波变换的奇异性检测理论，并将其应用于暂态行波故障特征的分析。提出了基于小波变换模极大值的电流行波故障启动元件、故障选线元件和故障选相元件。与传统方法相比，小波变换同时利用了电流行波中所包含的时间和频率两个信息来确定故障距离，使得测距结果更可靠。 行波信号是一种频率高达几百kHz的暂态信号，一般由单片机控制的数据采集方式很难记录该信号，因此要研制专用的高速数据采集卡。本文成功地设计了一种带GPS接口、采样率为5M、以复杂可编程逻辑器件构成周边逻辑的高速数据采集卡。该采集卡能存储故障前后2M字节的故障信息。实验调试的结果表明，该采集卡完全可以满足对行波信号进行记录的要求。其结构和工作原理本文在第五章作了详细的说明。更多还原

【Abstract】 The economic and reliable operation of power system requires a exact and fast determination of the point where a fault occurs. A method of quickly and accurately locating transmission line faults has been a much-desired tool for control center operators and the repair crews, and it is also an important research area in electrical engineering.Traveling wave is a mutation and singularity signal. The paper discuss the singularity detection theory of wavelet transform, this theory is applied to analysis of fault characteristics of the transient traveling waves.On this basis,a ’fault start element’,a ’fault line select element’and ’fault phase select element’are proposed. The method utilizes sufficiently properties of wavelet transform, both in time domain and in frequency domain. As a result, the measured fault location using this method is more accurate and reliable.Traveling wave’s frequency is more than hundreds thousand Hertz. General Single Chip Micyoco can’t acquire the signal possibly.So a high-speed data sampling board is designed technically. In the section of data acquisition, the paper discusses a new high-speed data sampling board. Its sampling rate reaches five millions and the memory is two millions byte. This sampling board has GPS interface periphery assistant electrocircuit has been realized with complicated programmable logic device. The structure and function is discussed detailedly in chapter five.更多还原