基于通信网络的分布式电源控制方法研究

发布时间：2018-05-08 06:40

本文选题：网络切换控制 + 分布式电源　；参考：《兰州理工大学》2017年硕士论文

【摘要】：分布式发电系统的出现不但节省了输变电投资、提高了供电网络的可靠性,也为偏远地区用户提供了方便,我国电网产业未来的发展趋势将是走以大电网供电为主分布式电源发电为辅,多种供电方式相结合的发展道路。可随着接入主配电网的分布式电源数量急剧增加,一些问题也变得不可避免。例如分布式发电系统接入后提升了系统整体复杂性和不可预测性,这对二次设备和通讯设施提出了新的要求。所以分布式电源在给人们生活带来方便的同时,也不可避免的为能源利用提出了新的挑战。因此,在高速发展分布式发电的同时,还需要同步提高对分布式电网整体远程监控的技术水平。主电网与分布式电源间的平稳切换是分布式电源为大电网提供补充和保障大电网自身安全的前提,也是保证分布式电源最大限度发挥自身优势的基础。本文从切换控制角度出发,将分布式电源两种运行模式看作是切换控制系统的两个子系统,结合网络化控制系统(Networked Control Systems,简称NCS)的相关知识对分布式电源的远程切换控制问题进行分析和研究。对于网络控制所存在的固有问题本文在考虑网络通信受限的基础上为了更加贴合工程实际,同时又考虑了切换时延和子系统不稳定情况,研究了在多种条件共同限制下的系统稳定性和控制器设计问题。本文的研究工作如下:(1)分布式电源并离网数学模型的建立。首先对现有主流分布式电源作以介绍,分析了风能、太阳能、燃料电池的结构特性和并网影响。然后简介了分布式电源远程控制的结构和遇到的问题。最后通过分布式电源并网模式和孤岛模式下的拓扑关系推导出两种模式下的系统状态空间模型,为下一步工作打下基础。(2)通信受限和切换时延共同影响下的分布式电源切换控制研究。在现有的通信控制技术研究基础之上将NCS与切换控制系统相结合形成一类新系统—网络切换控制系统(Networked Switched Control Systems,简称NSCS)。当网络引入后由于网络带宽等因素的限制,通信受限和时延变得不可避免,两者的存在将会影响系统的稳定性,对于这部分工作,本文基于平均驻留时间(Average Dwell Time,简称ADT)的概念和通信序列的处理方法及利用李雅普诺夫(Lyapunov)稳定性理论、线性矩阵不等式(LMI)等概念分析研究了系统控制器的设计方法和有限时间稳定的条件。最后通过数值仿真检验结果的正确性和有效性。(3)子系统不稳定下的分布式电源切换控制研究。子系统不稳定是造成工业系统失稳的重要因素,为了更加贴合工程实际,这部分研究内容基于平均驻留时间、总驻留时间的思想设计切换控制策略,研究子系统不稳定下的系统整体稳定性问题。最后通过两组算例验证了本章结论的正确性。通过把分布式电源并网与孤岛模式转换看做是一类特殊的切换系统,将网络切换控制系统研究所得结论与分布式电源的远程切换控制相结合,为实现广域分布式电源的远程互联互通和微电网并网和孤岛模式间平滑稳定的切换提供了理论支持。
[Abstract]:The emergence of the distributed generation system not only saves the investment and transformation investment, improves the reliability of the power supply network, but also provides convenience for the users in the remote areas. The future development trend of the power grid industry in China will be the development road of combining the large grid power supply with distributed power generation as the main power generation and the combination of various power supply modes. The number of distributed power sources in the power grid has increased rapidly, and some problems have become inevitable. For example, the distributed generation system has increased the overall complexity and unpredictability of the system, which puts forward new requirements for the two equipment and communication facilities. Energy utilization has put forward new challenges. Therefore, while developing distributed generation at high speed, it needs to improve the technical level of the remote monitoring of distributed grid as a whole. The stable switching between the main and the distributed power sources is the prerequisite for the distributed power supply for the large grid and the security of the large power grid itself, as well as the guarantee for the distribution of the power grid. From the angle of switching control, this paper regards the two operating modes of the distributed power supply as the two subsystems of the switching control system from the angle of switching control, and divides the remote switching control problem of the distributed power supply with the related knowledge of the networked control system (Networked Control Systems, short for short). For the inherent problem of network control, this paper studies the stability of the system and the design of the controller under the common restriction of a variety of conditions on the basis of considering the limited network communication to fit the engineering practice and considering the switching delay and the instability of the subsystems. (1) a mathematical model of distributed power supply and off network. First of all, the current mainstream distributed power is introduced, the structure characteristics of wind energy, solar energy and fuel cell are analyzed. Then the structure and problems of distributed power remote control are briefly introduced. Finally, the distributed power grid mode and the island mode are introduced. The topology relation derives the system state space model under two modes, which lays the foundation for the next work. (2) the study of distributed power switching control under the common influence of communication constraints and handoff delay. On the basis of the existing communication control technology research, the NCS and switching control system are combined to form a new system of network switching. Networked Switched Control Systems (NSCS). When the network is introduced because of network bandwidth and other factors, communication constraints and delay become inevitable, the existence of both will affect the stability of the system. For this part of the work, this paper is based on the concept of the mean standing time (Average Dwell Time, short for short). The processing method of the signal sequence and the use of Lee Yap Andrianof (Lyapunov) stability theory, linear matrix inequality (LMI) and other conceptual analysis are used to study the design method of the system controller and the conditions of the finite time stability. Finally, the correctness and effectiveness of the results are tested by numerical simulation. (3) the switching control of the distributed power supply under the instability of the subsystem. System instability is an important factor in the instability of the industrial system. In order to fit the engineering practice more, this part of the study is based on the thought design switching control strategy based on the average standing time and the total resident time. The system stability problem under the subsystem instability is studied. Finally, the chapter is verified by two groups of examples. The correctness of the theory is that the distributed power grid and island mode conversion are regarded as a special type of switching system. The conclusion of the network switching control system is combined with the remote switching control of the distributed power supply, so as to realize the remote interconnection and intercommunication of the wide area distributed power supply and the smooth stability between the microgrid connected network and the island mode. The handover provides theoretical support.

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM61

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