电压波动与闪变的检测方法研究.doc

电压波动与闪变的检测方法研究 摘要 近年来，依托电力电子技术发展起来的用电负荷日益增多，由于它们非线性、冲击性及不平衡的用电特性，造成诸多电能质量问题，电压波动与闪变就是其中之一。抑制电压波动与闪变，改善电能质量，必须首先对其进行准确测量和有效监视。但与电压偏差、三相不平衡、谐波、频率偏移等电能质量问题相比，电压波动与闪变的检测较为复杂，研究相对不足，测量设备较少，因此，本文选择这一问题进行进一步研究。 论文介绍了电压波动和闪变的基本概念、特征量以及抑制电压波动与闪变的常用方法，从电压波动信号的提取和闪变值的获得两方面系统地阐述了电压波动与闪变的检测原理，分析比较了现有测量方法和装置的特点和优劣，在此基础上，提出了用傅立叶检测方法。短时闪变严重度是IEC标准中衡量电能质量的一个重要指标。文中提出一种由FFT来完成计算的方法，方法核心在于利用傅立叶变换的方法对采集的信号进行傅立叶变换，借助Matlab语言对该方法的仿真，通过计算得到值，它是可行的和有效的。 关键词　With the development of power electronic technology，much nonlinear，impactive and imbalance load emerges in power system .As a result，power qualityhas deteriorated .The problem of voltage fluctuation and flicker，one issue of powerquality，becomes more and more serious .To solve the problem and improve powerquality，effective supervision and exact measurement is primary. However，compared with voltage deviation，unbalance of three phases，harmonics and frequency deviation，fluctuation and flicker are more complex to be detected，its research is relative to scarce，and the measuring devices are much less. Hence，some further research on measuring voltage fluctuation and flicker has been done in the paper. The basic concepts and character values of voltage fluctuation and flicker are introduced firstly，and then the common methods of suppress the voltage fluctuationare discussed. Further more，the process of extracting voltage fluctuation signal andcalculating flicker values is analyzed，and the principle of detecting voltage fluctuation and flicker is detailed. The short term flicker severity is an important index of power quality in the standards of IEC. A method to improve the accuracy of Pst is proposed in this paper, the corn of this method is that, first, interploation algorithms is applied on revising the results of FFT to overcome the disadvantage of spectral leakage and barrier effect Keywords　voltage fluctuation; flicker; Power quality; Flicker severity; IEC 不要删除行尾的分节符，此行不会被打印目录 …… I Abstract II 第1章 绪论 1 1.1 课题背景 1 1.2 电压波动与闪变检测技术的