电动汽车充换电站直流微网的控制策略研究

发布时间：2018-02-01 08:02

本文关键词： 电动汽车充电站直流微网分层控制　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：电动汽车和可再生能源发电技术(分布式电源)是解决能源危机和环境问题的两个重要途径。直流微网是一种将分布式电源和本地负荷通过直流母线结合起来的小型配电网结构,直流微网与交流配电网相比具有供电可靠性高、线路损耗小、电能质量优良等优势且更加适合电动汽车和分布式电源的接入。由此,本文提出采用直流微网构建电动汽车充换电站,以实现电动汽车与可再生能源的集成应用,从而达到协同增效的作用。本文以电动汽车充换电站直流微网为研究对象,主要研究了其构成以及相应的综合协调控制策略。首先,分析了电动汽车发展和现有交流配电网所遇到的问题,指出直流微网在应对这些问题上所具有的优势,从而提出电动汽车充换电站直流微网的概念。然后,分析设计了电动汽车充换电站直流微网的拓扑结构、电压等级以及主要组成单元。所设计系统采用两端型供电网络,直流母线采用双层式母线结构具有两个不同的电压等级。所设计系统的主要组成单元包括充换电站负荷,储能系统,并网变流器和光伏发电系统,本文分别分析了各组成单元的工作特性并设计了相应的电力电子接口电路,给出了数学模型,为仿真模型的搭建提供了理论基础。在此基础之上,本文提出了充换电站直流微网的分层式控制策略,该控制策略分为三层：上层属于配网级控制,负责制定微网的工作模式；中层属于微网级控制,负责制定微网的控制目标和主电源的工作方式；下层属于装置级控制,负责控制光伏出力调整和负荷投切等。此外,本文还分析了并网模式下和孤网模式下具体的控制流程。最后,本文利用PSCAD/EMTDC仿真软件搭建仿真模型,通过两个仿真算例验证了所设计系统及其控制策略的有效性。
[Abstract]:Electric vehicles and renewable energy generation technologies (distributed generation). DC microgrid is a small distribution network structure which combines distributed generation and local load through DC bus. Compared with AC distribution network, DC microgrid has the advantages of high reliability, low line loss and excellent power quality, and is more suitable for the access of electric vehicles and distributed power sources. In this paper, DC microgrid is used to construct electric vehicle charging and changing power station, so as to realize the integrated application of electric vehicle and renewable energy, so as to achieve the synergistic effect. In this paper, the DC microgrid of electric vehicle charging and changing power station is taken as the research object, and its composition and corresponding integrated coordinated control strategy are mainly studied. First of all. This paper analyzes the problems encountered in the development of electric vehicle and the existing AC distribution network, points out the advantages of DC microgrid in dealing with these problems, and then puts forward the concept of DC microgrid for electric vehicle charging power station. The topology, voltage grade and main components of DC microgrid of electric vehicle charging and changing power station are analyzed and designed. The DC busbar has two different voltage grades using the double-layer bus structure. The main components of the system include the load of the power station, the energy storage system, the grid-connected converter and the photovoltaic power generation system. In this paper, the working characteristics of each component unit are analyzed, and the corresponding power electronic interface circuit is designed, and the mathematical model is given, which provides a theoretical basis for the establishment of the simulation model. In this paper, a hierarchical control strategy for DC microgrid of charging and switching power station is proposed. The control strategy is divided into three layers: the upper layer belongs to the distribution network level control, which is responsible for establishing the working mode of the microgrid; The middle layer belongs to the microgrid level control, which is responsible for formulating the control goal of the microgrid and the working mode of the main power supply. The lower layer belongs to device level control, which is responsible for controlling photovoltaic output adjustment and load switching. In addition, this paper also analyzes the specific control flow in grid-connected mode and isolated grid mode. Finally. In this paper, PSCAD/EMTDC simulation software is used to build the simulation model, and two simulation examples are given to verify the effectiveness of the designed system and its control strategy.
【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】：U469.72;TM910.6

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