【作者】 李国庆；

【导师】 刘昊；

【作者基本信息】 中国矿业大学 ， 电气工程， 2022， 硕士

【摘要】 大量非线性负荷接入电力系统使得电能质量问题日益突出,并且随着电力市场化改革的不断推进,人们对电能质量的品质也更加关注。因此研究如何实现电能质量的综合评估对整个电网体系的建设、健康发展以及电力的合理定价有重要意义。首先论文介绍了电能质量的定义以及与其相关的各项指标,并在分析比较了现有的一些评估方法以及权重确定方法的基础上提出了一种“基于负荷分类的变权电能质量综合评估方法”。不同于传统主观赋权,根据设备分类进行主观赋权充分考虑了用电设备自身构造和运行特性,在进一步降低外界因素干扰的同时立足于用户角度,更加符合电能质量研究的本质意义;之后采用相对熵最小原则和变权思想对权重进行组合优化和动态调整,使权重更加全面可靠,也为后文优劣解距离法的改进提供了理论支持;最后引入模糊概率思想通过构造隶属度函数实现了对评估点的电能质量等级划分。其次为进一步实现对同一电能质量等级不同评估点之间的电能质量优劣比较,本文提出了一种“基于变权和改进优劣解距离法的电能质量综合评估方法”。首先通过上述同样的方法获得各指标权重;之后通过灰色关联分析原理对决策矩阵进行优化,弥补了传统优劣解距离法认为各评估指标之间相互独立的不足;然后用余弦相似度代替欧式距离,克服了通过欧式距离求取的贴近度在大小相等情形下无法给出明确结论的缺点,并通过算例证明了所提评估方法的有效性。最后以所提的“基于变权和改进优劣解距离法的电能质量综合评估方法”为基础设计了一款电能质量综合评估软件,可以帮助用户快捷地比较不同评估点的电能质量水平,准确、快速地掌握评估点的电能质量情况,进而开展相应的电能质量管理工作或市场交易活动。该论文有图22幅,表27个,参考文献80篇。更多还原

【Abstract】 A lot of non-linear loads connected to the power system has made the problem of power quality increasingly prominent,and with the ongoing reform of the power market,people are more concerned about the power quality.So,the research of how to achieve a comprehensive evaluation of power quality is very important for the construction and healthy development of the entire grid system and the rational pricing of electricity.Firstly,the thesis introduces the definition of power quality and its related index,and proposes a method that "power quality evaluation method based on variable weight and load classification",which by analyzing and comparing some existing evaluation methods and weight determination methods.Unlike the traditional subjective weighting,the weight based on equipment classification takes into account the structure and operating characteristics of the equipment itself,which further reduces the interference of external factors and stands on the user’s perspective,so it is more conforms to the essential meaning of power quality research;afterwards,the theory of relative entropy minimization principle and the idea of variable weight are used to optimize and dynamically adjust the weight in combination,which makes the weight more comprehensive and reliable and also provides theoretical support for the improvement of TOPSIS;finally,the fuzzy probability idea is introduced,and the power quality classification of the actual monitoring points is achieved by constructing the subordination function.Secondly,in order to further achieve the comparison of power quality between different evaluation points of the same power quality classification,an evaluation method that "power quality comprehensive evaluation method based on variable weight and improved TOPSIS" is proposed.First of all,the weight of each index is obtained by the same method as above;secondly,the decision matrix is optimized by the principle of grey correlation analysis,which overcomes the shortcomings of the traditional TOPSIS that considers the index to be independent of each other;finally,the cosine similarity is used instead of the euclidean distance to overcome the drawback that the proximity can’t give a clear conclusion in the case of equality,and the effectiveness of the evaluation method is proved by arithmetic examples.Finally,designing a power quality comprehensive evaluation software based on "power quality comprehensive evaluation method based on variable weight and improved TOPSIS",which helps users quickly compare the power quality level of different monitoring points,accurately and quickly grasp the comprehensive result of power quality at the evaluation point so that start the corresponding power quality management or market trading activities.The thesis has 22 figures,27 tables,80 references.更多还原