基于双曲S变换的电能质量信号降噪新方法  

A New Hyperbolic S-Transform Based Denoising Method of Power Quality Signals

作　　者：焦尚彬[1] 黄璜[1] 张青[1] 

机构地区：[1]西安理工大学自动化学院,陕西省西安市710048

出　　处：《电网技术》2011年第9期105-110,共6页Power System Technology

基　　金：陕西省自然科学基金资助项目(2009JQ7009);陕西省教育厅专项基金资助项目(2010JK750);西安理工大学科技创新计划的资助

摘　　要：为了更好地分析、检测电力系统中电能的质量，首先要降低电能质量信号中的噪声。利用S变换具有优秀时频呈现能力和时频分辨率的特点，采用双益窗函数，把电能质量有用信号以及噪声信号变换到相空间，将带噪声的信号分解到时间域和频率域，在给定的一个时间段内对信号的频率进行压制，给定权值为0～1，对边界进行插值平滑处理。然后通过S反变换得到最终需要的降噪后的电能质量信号。通过对4种典型的含噪电能质量信号（谐波信号、电压暂降信号、电压中断信号以及电压暂态扰动信号）进行降噪仿真实验，并与改进S变换进行降噪性能的比较，验证了文中所提方法的有效性。To better analyze and detect power quality of power system, firstly it is necessary to reduce the noise in power quality signals. In view of the advantages of S-transform that it possesses the ability of perfectly unfolding time-frequency characteristics and high time-frequency resolution, by use of hyperbolic window function the useful signals and noise signals of power quality are transformed into phase space and the signals containing noise are decomposed into time-domain and frequency domain, then in a given time interval the freqeuency of the signals is suppressed when the given weight is within the range from 0 to 1, and then the boundary is smoothed by interpolation method. Then by means of inverse S-transform the denoised power quality signals which is demanded is attained finally. The simulation experiments of four kinds of power quality signals containing noise, i.e., the harmonic singals, voltage sag signals, voltage interrupt signals and transient disturbance signals of voltage, are .performed. The effectivenss of the proposed method is verified by comparing the results of simulation experiments with the denoising results by improved S-transform.

关 键 词：电能质量 双曲S变换 S反变换 降噪 

分 类 号：TM93[电气工程—电力电子与电力传动]