基于小波变换和嵌入式零树编码的电力录波有损压缩应用  

Application of Power Disturbance Data Compression Based on Wavelet Transform and EZW Coding

作　　者：孙浩飞 吕新良 琚泽立 牛全保 王倩[3] 段玮 李宁[3] SUN Haofei;LÜXinliang;JU Zeli;NIU Quanbao;WANG Qian;DUAN Wei;LI Ning(Electric Power Research Institute,State Grid Shaanxi Electric Power Company,Xi’an 710100,Shaanxi,China;State Grid Shaanxi Electric Power Company,Xi’an 710048,China;Xi’an University of Technology,Xi’an 710048,Shaanxi,China)

机构地区：[1]国网陕西省电力公司电力科学研究院,陕西西安710100 [2]国网陕西省电力公司,陕西西安710048 [3]西安理工大学,陕西西安710048

出　　处：《电网与清洁能源》2020年第6期31-38,44,共9页Power System and Clean Energy

基　　金：国家自然科学基金青年基金资助项目(61503292)。

摘　　要：电力系统的录波装置能在较短时间内产生非常大的数据量,这给数据的储存和传输带来了很大的困难,如何有效地对录波数据进行压缩,是一个亟待解决的问题。在分析录波数据特点的基础上,应用了小波变换和嵌入式零树编码与算数编码,实现对录波数据的有效压缩。选取Daubechies 6阶小波基,并以提升格式的方式实现了该小波变换;同时通过对提升步骤中间计算过程取整,实现了整数小波变换。针对单小波变换的局限,选择了合适的多小波数据预处理方法。在数据编码阶段,采用了算术编码对嵌入式零树编码的输出作进一步压缩。嵌入式零树编码的应用能够实现可变码率的压缩;算术编码的应用进一步提高了压缩比。与传统的压缩方法相比,该方法实现了可变码率的压缩,压缩率和信噪比都有显著提高,运算量有较大降低,适合应用于电力系统录波数据压缩。As the data amount of power system transient recording is huge,how to effectively and efficiently compress the huge amount of data is a critical problem.This paper focuses on the data compression scheme based on the wavelet transform and data coding method.Based on the analysis of the characteristics of the recorded data,the paper applies wavelet transform and embedded zero-tree coding and arithmetic coding to achieve effective compression of the recorded data.First,the Daubechies 6th order wavelet base is selected,and the wavelet transform is realized in an improved format.At the same time,by rounding the middle calculation process of the lifting step,the integer wavelet transformation based on Daubechies 6th order wavelet is further realized.In view of the limitations of the single wavelet transform,the application of multi-wavelets such as GHM,CL in data compression is further studied.The effects of various preprocessing methods on the performance of multiwavelet applications are compared,and appropriate multiwavelet data preprocessing methods are selected.In the data encoding stage,embedded zero-tree encoding for one-dimensional data encoding is implemented,and arithmetic encoding is used to further compress the output of the embedded zero-tree encoding.The application of embedded zero-tree coding can achieve variable bit rate compression;the application of arithmetic coding further improves the compression ratio.Compared with the traditional compression method,this scheme achieves variable bit rate compression.The compression rate and signal-to-noise ratio are significantly improved,and the amount of calculation is greatly reduced.It is suitable for application to the compression of recorded data in power systems.

关 键 词：提升格式 多小波 嵌入式零树编码 数据压缩 

分 类 号：TM28[一般工业技术—材料科学与工程]