基于波形唯一和时–频特征匹配的单端行波保护和故障定位方法

Research on Single-end Traveling Wave Based Protection and Fault Location Method Based on Waveform Uniqueness and Feature Matching in the Time and Frequency Domain

单端行波保护和故障定位方法不需要通信通道和信号同步,降低了投资成本。基于单端检测故障行波波形时–频域唯一性理论,该文从时间–频率–幅值–极性等时–频多尺度观测宽频带行波信号的故障特性;从故障信号传播和折、反射过程的角度,既定性又定量分析了线路内部故障和相邻线路故障时,行波波形特征的时–频相关性与差异性;基于故障行波时–频三维波形,建立故障行波时频谱矩阵,并利用波形特征匹配技术,提出了一种单端行波保护和故障定位方法。综合利用时–频多尺度观测故障行波全景波形,有效克服了现有单端方法,基于局部故障信息而导致保护可靠性不高的缺陷,及对波头与模量波速准确检测的依赖。理论研究和大量算例分析结果表明：该方法实现简单,实用性较强,具有较高的灵敏度和可靠性。

Communication channels and time synchronization are not needed in single-end traveling wave protection and fault location method, which greatly decreases one-off investment and increases protection reliability. Based on the traveling waveform uniqueness detected at singleterminal, the broadband traveling wave signal was analyzed at multi-scale： arrival time, frequency, amplitude, and polarity, etc. From the transmission characteristics and refraction/reflection process of traveling wave, similarity and diversity of traveling wave within the time-frequency domain, when the faults were occurred within a transmission line or at different lines, are qualitative and quantitative analyzed. Time-frequency matrix was built based on the three-dimension waveform by CWT, and a single-end traveling wave protection and fault location is proposed by using feather matching technology. Comprehensively used multi-dimension fault information, it effectively overcomes the disadvantages of current methods, such as： used partial information from the time or frequency domain, heavily dependent on wave-front, or mode transmission velocity. Theoretical analysis and a large amount of simulation results show that the proposed protection and fault location schemes are easy to realize, and with high sensitivity and reliability.