电压波动与闪变检测方法的研究与改进

发布时间：2018-05-11 13:31

本文选题：电压波动 + 闪变　；参考：《长沙理工大学》2014年硕士论文

【摘要】：近年来,冲击性负荷以及非线性负荷与日俱增,导致电力系统负荷变得更加复杂,使得电网电能质量问题愈加严重。电压波动与闪变是亟待解决的主要电能质量问题之一。因此,采取相应有效措施对电压波动与闪变进行检测与研究,对推动闪变检测装置的开发与研制以及缓解电能质量问题具有十分深远的意义。首先,阐述了电压波动与闪变的基本概念、相关术语,了解电压波动与闪变检测技术的发展状况。在电压波动与闪变信号包络线提取方面,着重分析了几种常用的检波方法,重点对Hilbert变换法、Teager能量算子法、小波变换同步法以及平方检测法进行对比；在对提取出的信号包络线进行相关调制分量参数的估计方面,,重点比较了Pisarenko谐波分解法与扩展Prony算法两种常用的调制分量频谱估计算法。论文重点研究Hilbert变换与扩展Prony,并将Hilbert变换与扩展Prony算法结合进行电压闪变包络提取与分析,由于扩展Prony算法易受噪声影响,在分析非平稳信号以及含噪信号时,其效果不够理想,论文提出一种基于MM—Prony算法的电压闪变检测方法,该方法首先通过数学形态滤波器对信号进行滤波处理,解决噪声对提取闪变信号包络造成干扰的问题,再利用Hilbert变换提取出闪变包络,并通过扩展Prony算法对包络进行频谱分析,最终得到调制分量的幅值、频率等参数信息。通过算例分析,以上融合算法有效地提高了Prony算法在估计闪变信号各特征分量参数的准确性,同时说明了该方法在电力系统电压波动与闪变检测分析中具有较好的工程实际意义。
[Abstract]:In recent years, the impact load and nonlinear load are increasing day by day, which makes the power system load become more complex and makes the power quality problem more serious. Voltage fluctuation and flicker are one of the main power quality problems to be solved. Therefore, it is of great significance to take effective measures to detect and study voltage fluctuation and flicker, to promote the development and development of flicker detection device and to alleviate the problem of power quality. Firstly, the basic concepts and terms of voltage fluctuation and flicker are introduced, and the development of voltage fluctuation and flicker detection technology is discussed. In the aspect of voltage fluctuation and flicker signal envelope extraction, several commonly used detection methods are emphatically analyzed. The comparison of Hilbert transform method with Teager energy operator method, wavelet transform synchronization method and square detection method is emphasized. In order to estimate the parameters of the modulated components of the extracted envelope, two common modulation component spectrum estimation algorithms, Pisarenko harmonic decomposition method and extended Prony algorithm, are compared. This paper focuses on the study of Hilbert transform and extended Prony, and combines Hilbert transform with extended Prony algorithm to extract and analyze the voltage flicker envelope. Because the extended Prony algorithm is susceptible to noise, it is used to analyze non-stationary and noisy signals. This paper presents a voltage flicker detection method based on MM-Prony algorithm. Firstly, the signal is filtered by mathematical morphological filter to solve the problem of noise interference in extracting flicker signal envelope. Then the flicker envelope is extracted by Hilbert transform, and the amplitude, frequency and other parameter information of the modulation component are obtained by using the extended Prony algorithm to analyze the spectrum of the envelope. Through the example analysis, the above fusion algorithm can effectively improve the accuracy of Prony algorithm in estimating the parameters of each characteristic component of flicker signal. At the same time, it is shown that this method has good practical significance in the detection and analysis of voltage fluctuation and flicker in power system.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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