考虑微网的新型配电系统可靠性分析

发布时间：2018-03-08 09:31

本文选题：微电网　切入点：配电系统　出处：《山东大学》2015年硕士论文　论文类型：学位论文

【摘要】：常规能源逐渐枯竭以及环境污染日益严重促使电力研究人员广泛关注各种分布式发电技术,微网作为各分布式发电技术并入电网的高效可靠方式自然成为一大研究热点。微网运行方式灵活,既能作为一个小的电力系统独立运行,很大程度上提高了其中负荷的运行可靠性；又可以并入配电系统改变系统的结构形式,改善传统配电系统的运行状况。微网靠近负荷侧而不需要建设输电线路,对电系统经济运行有着积极作用。本文主要研究微网对系统运行可靠性的影响。微网接入改变了传统配电系统的辐射状结构形式,多电源对负荷供电方式极大程度上提高了负荷的运行可靠性。当配电系统发生故障时微网能够主动断开与主网的连接,保证微网内负荷的正常稳定运行。故障修复后微网能够通过PCC重新并入配网,微网可以在孤网与并网两种方式之间无缝切换。而且微网中分布式电源出力的随机性使得系统运行可靠性分析更加复杂,必须对原有配电系统可靠性分析的模型和方法做一定的改变。本文首先根据国内外微网的研究状况总结出微网的基本概念、微网的主要结构形式和微网中各种分布式电源的工作原理,进而根据微网的主要构成部分介绍了微网两种主要的运行方式以及几种主要控制方式,通过采取合理控制策略维持微网内电压和频率水平,保证微网稳定可靠运行。然后介绍了传统配电系统负荷点和系统侧的可靠性指标的物理含义以及计算方法,研究了构成配电网的各类元件的可靠性模型及其适用的情况,在此基础上给出了评估配电系统可靠性的几种常用方法,并以IEEE BUS6系统作为研究对象,采用序贯蒙特卡罗法进行仿真计算,将得到的结果与已知解析法得到的结果进行对比,从而验证了时序蒙特卡罗法评估配电系统可靠性的准确性。进而通过具体算例对微网孤岛运行方式展开研究,利用HOMER软件对某一海岛的常规供电与微网供电方式分别进行研究分析,验证了微网孤岛运行时对配电系统运行可靠性和经济性的积极作用,对海岛供电方式具有一定的借鉴意义和指导作用。最后利用最大熵原理模拟风速以及ARMA模型模拟光照强度,建立考虑风力发电和光伏出力不确定性的可靠性模型,以改进的IEEE BUS6系统为测试系统,通过时序蒙特卡罗法对该系统进行分析研究,分析微网接入点、分布式电源出力间歇性等因素对系统运行可靠性的影响作用,对微网的规划以及提高系统运行可靠性都有一定的指导意义。
[Abstract]:The gradual depletion of conventional energy sources and the increasing pollution of the environment have led power researchers to pay extensive attention to various distributed generation technologies. Microgrid, as an efficient and reliable way for distributed generation technology to be incorporated into power grid, has naturally become a hot research topic. Microgrid operation mode is flexible and can be operated independently as a small power system. The reliability of the load is improved to a great extent, and the distribution system can be incorporated into the distribution system to change the structure of the system and improve the operation of the traditional distribution system. The microgrid is close to the load side and does not require the construction of transmission lines. This paper mainly studies the effect of microgrid on system operation reliability. Microgrid access has changed the radiation structure of traditional distribution system. The operation reliability of the load is greatly improved by the mode of multi-power supply to the load. When the distribution system fails, the microgrid can actively disconnect from the main network. Ensure the normal and stable operation of the load in the microgrid. After the fault repair, the microgrid can be re-incorporated into the distribution network through PCC. The microgrid can be switched seamlessly between the isolated network and the grid-connected mode, and the randomness of the distributed power generation in the microgrid makes the reliability analysis of the system more complicated. Some changes must be made to the models and methods of reliability analysis of the original distribution system. Firstly, the basic concepts of microgrid are summarized according to the research situation of microgrid at home and abroad. The main structure of microgrid and the working principle of distributed power supply in microgrid are introduced. According to the main components of microgrid, two main operation modes and several main control modes of microgrid are introduced. The reasonable control strategy is adopted to maintain the voltage and frequency level in the microgrid to ensure the stable and reliable operation of the microgrid. Then the physical meaning and calculation method of the reliability index of the load point and the system side of the traditional distribution system are introduced. The reliability model and its application of various components in distribution network are studied. On the basis of this, several common methods to evaluate the reliability of distribution system are given, and the IEEE BUS6 system is taken as the research object. The sequential Monte Carlo method is used to simulate and calculate, and the results obtained are compared with those obtained by the known analytical method. Therefore, the accuracy of time sequence Monte Carlo method for evaluating the reliability of distribution system is verified, and the operation mode of microgrid islanding is studied by a concrete example. By using HOMER software, the conventional power supply and microgrid power supply mode in an island are studied and analyzed respectively, and the positive effect of microgrid islanding operation on the reliability and economy of distribution system is verified. Finally, the maximum entropy principle is used to simulate wind speed and ARMA model to simulate illumination intensity, and a reliability model considering uncertainty of wind power generation and photovoltaic output is established. Taking the improved IEEE BUS6 system as the test system, the system is analyzed by time sequence Monte Carlo method, and the effects of microgrid access points and distributed power generation intermittency on the reliability of the system are analyzed. It has certain guiding significance for the planning of microgrid and improving the reliability of the system.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM732

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