【作者】 曲静；

【导师】 卢继平；

【作者基本信息】 重庆大学 ， 电力系统及其自动化， 2002， 硕士

【摘要】 高压输电线路故障点的准确定位是提高电网安全经济运行的主要措施，准确的故障定位可以减轻巡线负担，加快线路恢复供电，减小因停电而造成的经济损失，具有巨大的社会和经济效益。单端行波故障测距方法的优点是其可靠性和精度在理论上不受线路类型、故障电阻及两侧系统的影响，但单端行波故障测距方法存在反射波的识别问题，且在近区还存在无法识别反射波区域。这就是本文的研究目的和中心。本文在广泛阅读和深入研究小波理论的基础上，论文提出了一种基于小波分析的奇异性理论对通过小波多尺度变换的高压输电线路故障电流暂态行波信号进行白噪声滤除的实用方法。其根本出发点是通过对信号奇异点与白噪声在小波多尺度变换下的不同特性的分析，得出简明的判据和算法，其优点是：在改善信噪比的同时，又提高了对突变信息的分辨率，以此达到对故障信号进行预处理的目的。论文深入地分析了高压线路故障暂态电流行波的波折、反射过程以及折、反射系数的特点，提出了新的单端行波故障测距方法，它不仅能够有效地识别出测距所用的反射波，而且几乎不受线路结构、长短、故障接地电阻、故障类型、系统阻抗的影响，在近区仍可以准确地进行测距；同时模拟阻波器的特征，设计了低通数字滤波器，对通过了低通数字滤波器的暂态故障电流行波再次进行小波分析，并利用本文提出的单端行波故障测距方法进行故障定位，结论是所提出的测距方法在实际应用中仍是有效的。再者对线路刚充电的暂态过程形成的暂态波进行小波分析，利用奇异性检测理论及本文提出的测距方法的核心思想，得出线路的准确长度。更多还原

【Abstract】 The accurate fault location of the fault position of high voltage transmission line is principal measure for improving safety and economic performance of the power restoration of line , cut down economic loss due to the failure ,which has great social and economic interests.The merits of single terminal fault location are its reliability and its accuracy isn’t affected by the type of line, fault resistance and two sides systems theoretically but this method has problems such as the identification of reflection wave and the unidentifiable area of reflection nearby which are research purpose and core of this paper.On the basis of extensive reading and research of theory of the wavelet, it is presented a practical method based on odd theory of wavelet analysis to remove the white noises from transient fault current traveling waves of high voltage transmission line via multi-size analysis of wavelet. The basic start point is by analyzing the difference characteristics of signal’s odd point and white noise under multi-size change of wavelet to gain simple criterion and arithmetic .The advantage is of improving the signal-noise rate, on the same time increasing the resolution of transient signal arrive at the aim of pre-processing of the fault classification and recognition.By analyzing the refraction、reflection process of fault transient current traveling wave of high voltage and characteristics of refraction 、reflection coefficient systematically, a new fault location method of single ended traveling wave is presented. It can not only identify the reflection wave for fault location efficiently, but also not be affected by the structure and length of line. Fault earthed resistance 、fault type 、system impedance and can locate fault in adjacent areas accurately. The low-pass digital filter is designed by simulating the feature of . The traveling wave of transient fault current of low-pass digital filter is analyzed again and the fault is located by the single ended traveling wave fault location method is valid in practice. It is also wavelet transformation that transient wave formed in the charged process of line, the accurate length of line can be got by using singularities and idea of fault location presented in the paper.更多还原