基于小波变换的窗奇异性指数计算及其在故障检测中的应用

摘要

Wavelet transform can well describe the singularity of signals. Based on the character of wavelet transform for studying singularity signals, a window singularity exponent is defined by overcoming the difficulty of local singularity exponent computation. The theory signals analysis indicated this exponent can describe the local singularity of signals, and its algorithm is fast and simple. By virtue of EMTDC software, the analysis result for the EHV transmission line fault indicated that this window singularity exponent can be a criterion of power system fault detection and discrimination, this is a new and efficient method for fault detection and protection.%小波变换能够充分刻画信号的奇异性,在探讨奇异信号的小波变换特性的基础上，克服信号局部奇异性指数计算的难点，定义了一种基于小波变换的窗奇异性指数，理论信号的分析计算表明，该窗奇异性指数能够既能表征信号的局部奇异特性，又具有计算简单快捷的特点。对一实际系统的EMTDC仿真信号的分析表明，以该指数作为EHV输电线路故障检测判据和区内外故障判别指标，具有较好的可靠性与实时性，是电网故障检测和继电保护的一种新颖的有效方法。