【作者】 王斌；

【导师】 孙鸣；

【作者基本信息】 合肥工业大学 ， 电力系统及其自动化， 2012， 硕士

【摘要】 当前,能源与环境问题已成为制约社会发展的关键因素。分布式发电由于可实现节能与环保的双赢,逐渐成为电力工业重要的研究方向。但是分布式发电也存在诸多不足。为解决电力系统与分布式发电接入的矛盾,充分发挥分布式发电的潜能,微电网概念应运而生,并逐渐成为国内外研究的热点。本文着重对低压微电网的运行特性和控制技术展开研究,主要内容如下：首先,深入分析典型微电网的运行模式及控制要求,并简要介绍微电网中分布式电源、储能装置、开关、电力电子设备、通讯技术及负荷的特性。其次,针对微电网中分布式电源多为逆变型的特点,重点研究了分布式电源常用的三种控制方法：恒功率控制、恒电压/恒频率控制和下垂控制,分析得出不同的分布式电源和不同的微电网系统运行方式适合采用不同的控制方法。在此基础上,研究了三种常用的微电网系统控制模式,即主从控制模式、对等控制模式和分层控制模式,并详细分析了这三种控制模式的实现方法及各自的特点。在理论分析的基础上,基于Matlab/Simulink仿真平台,搭建了微电源的V/f控制和PQ控制系统的仿真模型,并在此基础上建立了含有两个微电源的简单结构微电网仿真模型。采用主从控制策略对微电网并网运行状态和孤岛运行状态的部分特性进行仿真,得到的仿真数据验证了微电源控制方法及微电网控制策略的有效性。最后,针对交流微电网存在的运行控制问题,本文分析了发展直流微电网的必要性与可行性。在对直流微电网的基本结构进行分析的基础上,研究了直流微电网的运行特性。系统对储能装置的控制和减载措施的恰当使用均对直流微电网的稳定运行具有重要意义。本文对此进行了较深入的研究,给出了不同运行模式下,储能系统的控制策略及直流微电网在储能不足或长期孤岛运行时减载的具体方法。研究中发现直流微电网同样也存在一定的不足,发展混合微电网有其优势。为此在本文末节简要论述了混合微电网的概念和结构特征。更多还原

【Abstract】 At present, issues about energy and environment have become a key factor restricting social development. Distributed generation can achieve the win-win situation of energy saving and being environmentally friendly; therefore, it gradually becomes an important research orientation of the power industry. However, distributed generation has many deficiencies. The concept of microgrid was brought into being to solve the contradiction between the power system and the connection of distributed generation, and to give full play to the potential of distributed generation, and it has gradually become a hot topic of research at home and abroad. This paper mainly focuses on the research into the operating characteristics and controlling technology of low-voltage microgrid, and the main contents are as follows:First, the operation mode and controlling requirements of a typical microgrid are deeply analyzed, and a brief introduction of the distributed generator, energy storage devices, switches, power electronic devices, communications technology and characteristics of load is given.Second, on the basis that most of the distributed generators in microgrid are of the inverter-type, this paper mainly focuses on three commonly used controlling methods of distributed generators:constant power control, constant voltage/constant frequency control and drooping control. The conclusion is that different distributed generators and different operating mode of the microgrid system require different controlling methods. On this basis, three commonly used microgrid system controlling modes are researched, i.e. master slave control, peer-to-peer control and hierarchical control, with detailed analysis of implementation methods of the three controlling methods and their characteristics. Built on the basis of theoretical analysis, and based on Matlab/Simulink simulation platform, the simulation model of V/f control and PQ control system of microsources are built. Besides, a simple structure of microgrid simulation model containing two microsources is established. Simulation about part of the characteristics of grid-connected mode and islanded mode of microgrid is made using master slave control, and the simulation data verifies the effectiveness of the microsources controlling method and the microgrid controlling strategy.Finally, the necessity and feasibility of the development of DC microgrid are analyzed aiming at the problems of AC microgrid operational control. This paper researches on operating characteristics of the DC microgrid on the basis of analyzing the basic structure of the DC microgrid. The control of energy storage devices and appropriate use of load shedding measures in the system have an important significance to the stable operation of the DC microgrid. In this paper relevant research has been deeply made, and in different operating modes the paper provides controlling strategy of the energy storage system and specific method of load shedding in DC microgrid when the storage is inadequate or the system is in a long period of island running. It is found in this research that there are also certain disadvantages in the development of DC microgrid, while the development of hybrid microgrid has its advantages. Therefore, there is brief description in the end of this paper about the concept, structure, characteristics of hybrid microgrid.更多还原