基于变步长LMS的电力系统谐波检测算法研究

发布时间：2018-06-26 02:38

本文选题：LMS算法 + 谐波检测　；参考：《辽宁工程技术大学》2014年硕士论文

【摘要】：文章在论述自适应谐波检测基本原理的基础上,对传统的LMS算法进行了较深入的理论分析和研究。针对固定步长的LMS算法在收敛度和稳态误差之间存在的矛盾,本文提出了一种快速收敛的变步长LMS自适应算法。该算法利用改进的相干平均估计调节步长的迭代公式,并引入动量项提高权值的跨度,使新的算法具备了较快的收敛速度和较强的跟踪能力。并将其应用于电力系统的谐波检测中,与传统的LMS算法进行仿真比较,证明新算法改善了LMS算法的在谐波检测中的性能,获得了较好的效果。考虑到在实际环境中噪声的干扰及LMS算法自身的缺点,本文在综合现有的变步长算法优点的基础上,提出了一种基于改进的双曲函数的变步长自适应滤波算法。并从理论上对新算法的收敛性、抗干扰能力及跟踪能力作了分析。最后通过MATALB软件将该算法与现有的变步长算法作了滤波仿真比较,验证了新算法在现有的滤波方法中的优越性。
[Abstract]:Based on the discussion of the basic principle of adaptive harmonic detection, the traditional LMS algorithm is analyzed and studied in detail. In view of the contradiction between convergence degree and steady-state error of fixed-step LMS algorithm, a fast convergent variable step size LMS adaptive algorithm is proposed in this paper. The improved coherent average estimation is used to adjust the iterative formula of step size, and the momentum term is introduced to increase the span of the weight, which makes the new algorithm have faster convergence speed and better tracking ability. Compared with the traditional LMS algorithm, the new algorithm can improve the performance of the LMS algorithm in harmonic detection and obtain better results. Considering the noise interference in the real environment and the shortcomings of the LMS algorithm, a variable step size adaptive filtering algorithm based on the improved hyperbolic function is proposed based on the advantages of the existing variable step size algorithm. The convergence, anti-interference and tracking ability of the new algorithm are analyzed theoretically. Finally, the new algorithm is compared with the existing variable step size algorithm by MATALB software, which verifies the superiority of the new algorithm in the existing filtering methods.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM935

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