结合EMD-WVD和布谷鸟搜索算法的输电线路故障暂态保护

Transient Protection for Transmission Line Fault Combining Empirical Mode Decomposition-Wigner Ville Distribution and Cuckoo Search Algorithm

为促进基于波形唯一性暂态保护原理的实用化,提出了一种结合经验模态分解-维格纳威尔分布(EMD-WVD)和布谷鸟搜索算法的输电线路暂态保护方法。该方法利用EMD处理故障暂态信号,得到不同频段的单分量信号;采用波形相关性系数对各单分量信号分别与原暂态信号进行相似度计算,筛选真实暂态信号分量。然后,对真分量分别求WVD,并将所有真分量的WVD进行线性叠加获得的能量谱密度图与故障样本库中的能量谱密度图不断迭代匹配计算相似度,依据相似度判别区内外故障,实现输电线路故障快速可靠保护。仿真结果表明,EMD-WVD方法能有效提高故障暂态波形分析的准确度,布谷鸟搜索算法能有效提高波形匹配速度,两者结合有望促进暂态保护的实用化。

In order to promote the practicality of the transient protection principle based on waveform uniqueness, this paper proposes a transient protection method for transmission lines combining empirical mode decomposition-Wigner Ville distribution(EMD-WVD) and cuckoo search(CS) algorithm. This method uses EMD to process fault transient signals to obtain singlecomponent signals in different frequency bands. Waveform correlation coefficients are used to calculate the similarity between each single-component signal and the original transient signal to screen the true transient signal components. Then, WVDs of the true components are obtained respectively. The WVDs of all the true components are linearly superimposed to obtain the energy spectral density map, which is then iteratively matched with the energy spectral density map in the fault sample database to calculate the similarity. Internal and external faults are identified based on similarity to achieve the fast and reliable protection from transmission line faults. Simulation results show that the EMD-WVD method can effectively improve the accuracy of fault transient waveform analysis, and the CS algorithm can effectively improve the waveform matching speed. The combination of the two is expected to promote the practical application of transient protection.