大型受端电网限制短路电流措施研究

发布时间：2018-04-05 05:13

本文选题：受端电网　切入点：短路电流　出处：《华北电力大学》2014年硕士论文

【摘要】：中国电力能源与负荷中心分离的特性,使得我国电网呈现送端和受端两极特性。随着特高压建设工程的推进,系统间电气距离日益缩小,加上受端电网内部结构联系过于紧密,使得短路电流超标的现象逐年加重,严重制约着电网的发展。因此,研究如何解决受端电网已成为电网当前建设的当务之急。受端电网由于内部自供电源所占比例逐年减小,系统连接过于紧密,短路电流水平呈现出以下特点：局部站点超标和区域性短路电流水平过高。本文主要针对受端电网的这两个特性进行分析和研究,得出适用于不同情况的限流措施。本文首先研究和对比现行应用的多种限流措施特点,总结各种限流措施的限流原理以及对受端电网的适用性。然后,就受端电网局部站点短路电流超标的现象,建立自阻抗模型,分析其超标机理,得出基于电网网络参数的限流措施优化选择模型,应用于某实际电网,计算结果证明该模型的有效性。最后本文就区域性短路电流水平过高的问题,分析短路电流分布不均匀产生的原因以及目前电网采取的限流方案,总结不同分区模式限制短路电流的特点,提出基于熵权理论的多目标决策的限流方案优化模型,用以选择最优限流方案,应用于某实际电网证明其有效性和实用性。
[Abstract]:Because of the separation of power source and load center in China, the power grid in China is characterized by two poles: the terminal and the receiver.With the development of UHV construction project, the electric distance between the systems is shrinking day by day, and the internal structure of the receiving network is too close, which makes the short-circuit current exceed the standard, which seriously restricts the development of the power grid.Therefore, the research on how to solve the receiving power grid has become the urgent task of the current power grid construction.Because the proportion of internal self-supply power is decreasing year by year, the system connection is too tight, and the short-circuit current level shows the following characteristics: the local stations exceed the standard and the regional short-circuit current level is too high.In this paper, the two characteristics of the receiver power network are analyzed and studied, and the current limiting measures suitable for different situations are obtained.In this paper, the characteristics of various current limiting measures are studied and compared, and the current limiting principle and applicability of the current limiting measures to the receiving power network are summarized.Then, the self-impedance model is established for the phenomenon that the short-circuit current of the local station of the receiving network exceeds the standard, and the mechanism of exceeding the standard is analyzed, and the optimal selection model of the current limiting measures based on the network parameters is obtained, which is applied to a practical power network.The results show that the model is effective.Finally, this paper analyzes the causes of the uneven distribution of short-circuit current and the current limiting scheme adopted in the current power network, and summarizes the characteristics of limiting short-circuit current in different zonal modes, aiming at the problem of high level of regional short-circuit current.An optimization model of multi-objective decision limiting scheme based on entropy weight theory is proposed, which is used to select the optimal current limiting scheme. It is applied to a practical power network to prove its validity and practicability.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM713

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