小波变换在暂态电能质量分析中的应用研究.doc


小波变换在暂态电能质量分析中的应用
研究#
李雅梅,郭琳*
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(辽宁工程技术大学电气与控制工程学院,辽宁葫芦岛 125105)
摘要:在电力系统中,随着用电负荷迅速增加,特别是不对称、冲击性、非线性负荷容量的
不断增长,电能质量的监测和控制已成为一项亟待解决的系统工程问题。本文应用现代数字
信号处理的小波变换理论,设计算法实现对暂态电能指标的电磁瞬态震荡、电磁瞬态冲击的
监测。仿真结果表明,基于时频分析理论的算法不仅能分析出信号中的各频率成分,而且能
够准确定位暂态信号中各频率分量出现的时间,实现了对信号时域和频域的同步的测量。选
择快速高性能的 DSP 芯片构成电能质量监测系统,即可实现电能质量的在线监测,这为电能
质量的进一步改善提供了重要的基础和依据,满足了越来越多的敏感负载对电能质量提出的
更高要求。
关键词:数字信号处理器;暂态电能质量;小波变换;监测
中图分类号:TM743
Application Research on Wavelet Transform Theory for
Transient-State Power Quality Monitoring
LI Yamei, GUO Lin
(Faculty of Electrical and Control Engineering, Liaoning Technical University,
LiaoNing HuLuDao 125105)
Abstract: with the rapid increase of electric loads, especially those asymmetrical, impacting and
impacting and nonlinear ones in modern power grid, power quality monitoring and control has
e an urgent need to solve the engineering problem. By using wavelet transform theory of
modern digital signal processing, some algorithms are proposed to monitor the disturbance signals
like ic transient vibrating, ic transient shocksignals in the
transient-state power. Simulation results show that the theory of time-frequency analysis based
algorithms can not only analyze the ponents, but also be able to accurately locate
the signal in the transient time for each ponent appeared, which achieves
synchronous measurement for the signal in both time and frequency domain. By choosing a fast
DSP chip, a on-line power quality monitoring system can be constructed, which provides
significant foundation and basis for the further improvement of power quality, and meet the high
needs better of more and more sensitive loads.
Keywords: digital signal processing; transient-state power quality; wavelet transform; monitoring
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0 引言
电能是目前使用最广泛、最环保、最便利的能源。电能作为一种特殊的能耗商品,其质
量问题也受到了越来越广泛的关注。一方面,现代用电设备许多都是基于微处理器的,这些
设备对电磁干扰极为敏感,对电能质量提出了更高的要求;另一方面,随着节能技术和自动
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化技术的推广,各种整流、变流、变频等电力电子装置,数量日益增多,容量日益扩大,这
些非线性负载给电网带来了更严重的污染,由此加剧了电能供用双方的矛盾