【作者】 祝纯；

【导师】 朱守真；

【作者基本信息】 清华大学 ， 电气工程， 2005， 硕士

【摘要】 对电能质量问题的研究,是电力系统研究领域的重要前沿。电力系统中非线性负荷的日益增多,电能质量问题对电网和配电系统造成的直接危害和可能对人类生活和生产造成的损失也越来越大,电能质量直接关系到国民经济的总体效益。由于各种原因,在供电可靠性和电网电压幅度的稳定水平等指标上,我国的情况尤其落后。如何提高和保证电能质量,已成为国内外电工领域迫切需要解决的重要课题之一。本论文对电能质量问题的分类以及各类电能质量问题的特征进行了综述。论文采用二进正交小波变换的方法、多分辨分析方法以及功率突变法等分析方法对各类短时电能质量扰动信号进行分析,设计出一种基于二进小波分析的计算方法,用于检测暂态脉冲、暂态振荡、电压凹陷与电压骤升等电能质量暂态扰动信号,并将扰动进行自动类型识别。通过对小波理论的研究以及数据测试实践,该方法在实际应用中取得了良好的效果。目前,国内外都在谐波源辨识方面的研究,希望发展一种适用更广泛的可靠的谐波源定位方法,来解决现有的电能质量责任判定问题。本论文开展了这方面的探讨。论文分析了电力系统中的谐波源对电网的影响,研究了不同性质的负载与谐波的关系。列举了几种现在正在研究中的识别谐波源的技术原理,着重研究了当前电力系统中应用最广泛的谐波潮流计算和谐波功率流向法的应用,推导了谐波功率流向法的在不用网络参数下的适用性,总结了影响功率流向法适用范围和可靠性的相关因素。更多还原

【Abstract】 Power Quality (PQ) research is an important leading edge in the powersystem. By the development of modem technology, factors of power qualityproblems are increased. For example, using non-linear loads such as powerelectric devices, and start and stop of large electric equipment load to a resultthat the problems become much more serious. For some reasons, China isespecially lagging behind in reliability and stability of power system voltageindex. Therefore, how to enhance and ensure power quality is becoming animperious task in the field of the world electrical area.In present thesis, the classification and feature description of the most ofdisturbance waveforms are introduced and analyzed. One of the mostimportant issues in PQ problems is how to detect and classify disturbancewaveforms automatically in an efficient manner, which is the basis of PQtransient disturbance monitoring arithmetic and auto-classification. Dyadicwavelet transform, multi-resolution analysis and power mutation analysis areused to investigate kinds of transient power quality disturbance signal. Amethod is designed based on dyadic wavelet transform, which is to examinepower quality signal such as impulsive, oscillatory, sag, swell and notchwaveforms and auto-classify these kinds of disturbances. Through theacademic resource and data test, this method proves a good result in practice.Presently, technology research is doing all over the world to develop aproved method which is more reliable in abroad areas for harmonic sourcelocation to solve the problem of power quality responsibility determination.In this paper, these problems are discussed. Influence of power system byharmonic source and loads of different characteristics are discussed in thepaper. Some technology theories on harmonic source recognition areparticularized especially the application of harmonic flow calculation andharmonic power direction method. The applicability of harmonic powerdirection method under different system parameters is derived and thecorrelated aspects that affect the reliability and application condition ofharmonic power direction are summarized.更多还原