扰动信号最优阈值降噪-电测与仪表.doc

基于S变换与全局最优阈值的暂态扰动信号降噪* 林琳1，，，（1. ， 132022；2.新疆电力公司 电力科学研究院，乌鲁木齐 830000；. 东北电力大学，132012；4. 山东电力公司 德州供电公司，山东 德州 253000） 摘要：’s算法，计算全局最优阈值，进行滤波降噪；最后，将降噪后的时-频矩阵进行S变换逆变换获得降噪后的扰动信号。仿真实验证明，新方法能够有效保留信号中的高频扰动成分，降噪效果好，能够满足扰动信号分析要求。 关键词：；；；’s算法； 中图分类号：TM714 文献标识码： 文章编号：1001-1390（201）-0000-00 Transient disturbance signals de-noising based on S-transform and optimal global threshold Lin Lin1, Yang Jincheng2, Zhang Weihui3, Yang Yongjian2, Wang Xinku4, Huang Nantian3 (1. College of Information and Control Engineering, Jilin Institute of Chemical Technology, Jilin 132022, Jilin, China. 2. Electric Power Research Institute, Xinjiang Power Company, Urumqi 830000, China. 3. College of Electrical Engineering, Northeast Dianli University, Jilin 132012, Jilin, China. 4. Dezhou Power Supply Company, Shandong Power Company, Dezhou 253000, Shandong, China) Abstract: The details in the high frequency area of transient disturbances signals are always destroyed by current the signal de-noising methods. A new approach of disturbance signals de-nosing based on S-transform and local optimal global threshold has been proposed in this paper. Firstly, the time-frequency matrixes of disturbances signals were calculated by the S-transform. Secondly, the amplitudes of S-transform modular matrix were transformed to grey level presentation. Then, the optimal global threshold was chosen by Otsu’s algorithm, and the thresholds were used to de-noise the disturbance signals. Finally, the time-frequency matrix after de-noising was transformed into disturbances signals by invert S-transform. The simulation results show that the new method can remain the high frequency elements of the disturbances effectively with excellent de-nosing ability. It could satisfy the requirements of disturbance signals analysis. Keywords: power quality, transient disturbance, S-transform, Otsu’s algorithm, optimal global threshold 0　引 言 ’s方法，计算全局最优阈值，并根据该阈值对ST时-频矩阵进行降噪，将幅值低于阈值的时-频点归零处理；最后，将降噪后的ST矩阵，通过