摘要
针对暂态电能质量扰动信号消噪问题,小波阈值去噪是一种简单有效的方法.传统的小波阈值消噪分硬阈值消噪和软阈值消噪两种,但是这两种方法都存在不足之处.基于非线性小波阈值算法,采用迭代方法确定最佳消噪阈值.针对实际应用中噪声方差未知或变化的情况,自适应估计噪声强度和阈值.仿真结果表明该方法不仅一定程度上改进了噪声估计,而且在消噪效果上优于传统的固定阈值、无偏风险阈值、启发式阈值、极大极小阈值四种阈值规则.
For the problem of transient power quality disturbance signal denoising,wavelet threshold denoising is a simple and effective method.The typical threshold denoising approaches include soft threshold and hard threshold.However,both methods have shortcomings.Based on a nonlinear wavelet threshold,a recursive way is used to determine the optimal denoising threshold in this paper.In practical applications,the noise variance is always unknown or changeable.This approach can estimate the noise variance and the threshold adaptively.The simulation results show the proposed approach not only improves noise estimation to a certain extent,but also makes the denoising effectiveness better than the traditional four threshold rules,such as fixed threshold,unbiased risk threshold,heuristic threshold,and min-max threshold.
出处
《浙江工业大学学报》
CAS
北大核心
2011年第1期92-96,共5页
Journal of Zhejiang University of Technology
关键词
电能质量
迭代算法
自适应
消噪
power quality
recursive algorithm
adaptive
denoising
