配电网电压波动与闪变问题的研究

发布时间：2018-06-21 20:14

本文选题：电压波动与闪变 + IEC闪变仪　；参考：《中国矿业大学》2014年硕士论文

【摘要】：随着我国经济的发展和科学技术的提高，对电能的需求不断增加，同时用电负荷呈现出非线性、非对称性和波动性，随着波动性负荷所占比例不断变大，给电网的电能质量带来新的威胁。作为电能质量的一个重要指标，，电压波动与闪变愈发得到大家的关注。本文首先从电压波动与闪变的概念入手，介绍了其定义、标准与衡量电压波动与闪变的特征量，分析了闪变的来源、危害及其补偿措施，然后简单的介绍了现有的电压波动与闪变检测方法的原理、特点并做了对比。由于在此之前国际电工委员会（IEC）发布了闪变仪的设计框图，本文通过运用仿真软件对该框图进行了验证并且论述了误差出现的原因。针对某变电站电能质量测试中发现的发生单相接地时电压波动与闪变值产生突变的现象，应用仿真软件分析了在发生单相接地情况下平方检测法的利弊，并研究了其对电压闪变问题的影响。最后对IEC推荐的平方检测算法提出了改进措施，并进行了仿真验证，结果表明改进后的平方检测法在发生单相接地情况下能够避免电压波动与闪变产生的突变。对于突变的、非平稳的电压闪变信号的检测，本文探讨了基于拟同步检波与小波变换的电压闪变检测方法。通过仿真，验证了小波变换应用于电压波动与闪变检测的可行性。小波多分辨率分析能够准确检测出电压闪变分量的幅值、频率等信息，并能够准确地检测出闪变发生和结束的时间。
[Abstract]:With the development of our economy and the improvement of science and technology, the demand for electric energy is increasing, and the load of electricity is nonlinear, asymmetric and fluctuating, and the proportion of fluctuating load is increasing. It poses a new threat to the power quality of the power grid. As an important indicator of power quality, voltage fluctuation and flicker have attracted more and more attention. This paper begins with the concept of voltage fluctuation and flicker, introduces its definition, standard and characteristic quantity of measuring voltage fluctuation and flicker, analyzes the source, harm and compensation measures of flicker. Then the principle and characteristics of the existing voltage fluctuation and flicker detection methods are briefly introduced and compared. Since the International Electrotechnical Commission (IEC) has published the design block diagram of the flicker instrument, this paper verifies the block diagram by using the simulation software and discusses the reasons for the error. In view of the phenomenon of voltage fluctuation and sudden change of flicker value found in the power quality test of a substation, the advantages and disadvantages of square detection method in the case of single-phase grounding are analyzed by using simulation software. The influence of voltage flicker is studied. In the end, the improved square detection algorithm recommended by IEC is proposed, and the simulation results show that the improved square detection method can avoid voltage fluctuation and flicker mutation in the case of single-phase grounding. For the detection of abrupt, non-stationary voltage flicker signals, a voltage flicker detection method based on quasi-synchronous detection and wavelet transform is discussed in this paper. The feasibility of applying wavelet transform to voltage fluctuation and flicker detection is verified by simulation. Wavelet Multiresolution Analysis can accurately detect the amplitude and frequency of the flicker component, and can accurately detect the occurrence and end time of the flicker.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM73

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