电力录波数据采集噪声与数据压缩方案的研究-电气工程专业论文.docxVIP

Classified Index: TM764.1 U.D.C: 621.3 Dissertation for the Master Degree in Engineering RESEARCH ON NOISE OF DATA ACQUISITION AND DATA COMPRESSION IN POWER RECORDING SYSTEM Candidate: Liu Dan Supervisor: Prof. Zhang Donglai Academic Degree Applied for: Master of Engineering Speciality: Electrical Engineering Affiliation: Shenzhen Graduate School Date of Defence: June, 2012 Degree-Conferring-Institution: Harbin Institute of Technology 哈尔 哈尔滨工业大学工学硕士学位论文 - - I - 摘 要 电力监控装置实现了整个电力网络的的紧密协调，对于提高电力供应稳 定性极为重要。实时准确的电力采集数据是保证电力监控装置稳定运行的重 要依据，而长时间连续工作的电力监控装置所产生的庞大数据必然影响电力 网络的工作效率。在全球发展智能电网和电网规模逐渐扩大的形势下，高效 的电力数据压缩方法是改善电力数据通信能力和存储成本的重要技术。提高 数据压缩比不仅需要优化压缩算法，采样噪声引起的数据相关性下降也是制 约压缩效果的关键因素。 本文针对实际的电力录波装置，分析了数据采集系统的硬件结构与工作 原理，并测试了系统的噪声情况；通过理论计算与行为级建模两种方法分析 了电力信号采样过程中的振幅噪声、相位噪声和时钟抖动；在噪声分析的基 础上，分别测试了信号调理电路噪声、锁相环环节的相位噪声和 AD 时钟抖 动单独作用对电力采样数据压缩效果的影响，确定了影响数据压缩的主要噪 声源，并给出了相应的噪声抑制方法；针对电力稳态采样数据，提出基于二 维提升小波变换的改进压缩方法，通过与原始方法的压缩效果进行对比，确 定了改进方案的优势，并实现实际数据采集系统的在线压缩，通过在线测试 验证了方案的可行性。 本文从电力数据采集系统本身出发，从噪声抑制和优化数据压缩方案两 个方面提高电力数据压缩效果，为提高电力录波数据的采样品质和压缩效果 提供了理论依据。 关键词：电力数据采集；采样噪声；相位噪声；时钟抖动；数据压缩 - - II - Abstract Power monitoring device can help to achieve close-coordination of the entire power grid, and it is critical to improve the reliability of power supply. Real-time and accurate data of power system is an important basis to ensure the stable operation of power monitoring device, however, if power monitoring devices keep on working for long time, the massive data will inevitably affect the performance of the power grid. In the situation of the global development of smart grid and the gradual expansion of power structure, efficient data compression scheme is an effective solution for improving communication capability and storage costs. In order to increase data compression ratio, it depends on not only optimizing compression algorithm, but also improving the correlation of data by restraining sampling noise. This thesis is based on an actual power recording system, firstly introduces the hardware