基于Kaiser自卷积窗的相位比较式输电线路故障定位方法

摘要

长距离输电线路对地分布电容引起电流行波畸变，不利于行波初始时刻的准确标定，并且弧垂因素的累积加大了定位误差。为缩短行波双端间距，保证在基频波动环境下可靠定位，提高故障定位精度，提出一种基于Kaiser自卷积窗FFT相位比较式输电线路故障定位方法。该方法设置多个电流测量点，采用FFT程序求解电流故障分量的相位，比较相邻测点的相位差以判别故障区段；利用Kaiser自卷积窗优良可调的旁瓣特性，充分抑制FFT相位求解时的频谱泄漏效应，提高了相位比较的可靠性。理论分析了产生相位频谱泄漏的原因，阐述了Kaiser自卷积窗的旁瓣特性，最后通过仿真验证所提方法的正确性。结果表明方法可有效抑制频谱泄漏，相位比较可靠性高，基频波动下仍能可靠定位。%Current traveling waves attenuation caused by ground distributed capacitance of long-distance transmission lines goes against the calibration of initial fault traveling wave arriving times, and arc sag increases location errors. To shorten double ends distance and ensure reliability of fault location under the fundamental frequency fluctuations, and improve its accuracy, this paper proposes a novel fault location scheme for transmission lines based on phase comparison with Kaiser self-convolution windows FFT. This scheme uses FFT program to solve the phase current fault component of multiple current measurements which are compared for determining fault selection; uses excellent sidelobe characteristics of Kaiser self-convolution window to restrain spectral leakage, then the reliability of phase comparison is increased. This paper theoretically analyzes the causes of the phase spectrum leakage, then elaborates the sidelobe characteristics, and finally, verifies the correctness of the proposed method by simulation. The results show that the proposed method can effectively suppress spectral leakage with a high reliability.