基于小波变换修正幅值的电力系统频率偏移诊断方法  

A METHOD TO DIAGNOSE FREQUENCY SHIFT OF POWER SYSTEMS BASED ON MODIFIED AMPLITUDE OF WAVELET TRANSFORM

作　　者：朱锋峰[1] 任震[2] 黄雯莹[1] 

机构地区：[1]华南理工大学理学院,广东省广州市510640 [2]华南理工大学电力学院,广东省广州市510640

出　　处：《电网技术》2004年第11期34-37,共4页Power System Technology

基　　金：国家自然科学基金(50077008);广东省自然科学基金(033044)

摘　　要：针对电力系统信号频率偏移的检测进行了研究。首先提出了两个实值小波函数以及基于这两个小波变换的修正幅值的概念,推导出这两个小波变换的递推算法。然后从理论上说明了对于正弦电压信号,基于这两个实值小波变换的修正幅值不仅能准确地确定在哪一段时间间隔电压的频率是工频频率,哪一段时间间隔电压的频率偏离了工频频率,还具备检测频率偏离工频频率方向及分辨正弦信号中所包含的幅值信息的功能。最后的仿真结果表明,基于这两个实值小波变换的修正幅值对于诊断正弦信号的频率偏移是行之有效的方法。Frequency is one of important indices in power quality evaluation. Here, the detection of frequency shifts of power system signals is studied. Firstly, two real mother wavelets and the concept of the modified amplitude based on the transform of the two wavelets are presented, the recurrence algorithm of the two wavelet transforms are derived. Secondly, it is theoretically explained that for sinusoidal voltage signals not only the modified amplitude based on the transform of the two real wavelets can accurately determine that at which time interval the frequency of the voltage is the fundamental frequency and at which time interval the frequency of the voltage shift occurs. In addition, the modified amplitude can detect the direction in which the voltage frequency deflects the fundamental frequency and can resolve the amplitude information involved in the sinusoidal signal. Simulation results show that the modified amplitude based on the transform of the two real wavelets is an effective tool to diagnose the frequency shifts of sinusoidal signals.

关 键 词：电力系统 频率偏移诊断方法 小波变换 修正幅值 电网 

分 类 号：TM711[电气工程—电力系统及自动化]