基于混合系统理论的微电网控制及稳定性研究

发布时间：2018-05-14 14:23

本文选题：混合系统 + 微电网　；参考：《湖南工业大学》2015年硕士论文

【摘要】：本文将混合系统理论应用到微电网,由于微电网中存在大量的开关器件,开关的切换使得微电网表现为连续动态和离散切换事件之间的混合行为,因此微电网是一个典型的混合系统,本文主要以混合系统理论研究微电网,为微电网设计了混合控制方案,并研究了微电网的稳定性。首先介绍了混合系统理论的研究背景及研究进展、本文的研究目的及意义、微电网的概念及控制方法以及本文将用到的稳定性基础知识。其次本文将区间脉冲系统理论应用到微电网,通过定义脉冲系统鲁棒事件指数输入到状态稳定,并给出了鲁棒事件指数输入到状态稳定性的等价条件定理;将上述结果应用到区间脉冲系统中,定义了区间脉冲系统指数输入到状态稳定性,并给出了区间脉冲系统事件指数输入到状态稳定性的等价条件的定理;最后将前述结果应用到区间脉冲切换系统,并给出了区间脉冲切换系统鲁棒指数输入到状态稳定性的等价条件的定理。由之前的理论可知,如果限制不确定矩阵在较小的鲁棒区域中,会增加它的衰减率,并且根据区间脉冲切换系统指数输入到状态稳定性定理,为VSC设计了一个区间脉冲切换控制系统,并研究了负载扰动和孤岛扰动两种外在输入情况下微电网储能系统的输入到状态稳定,通过仿真实验,系统在这两种情况下均达到了输入到状态稳定。最后研究了含多个分布式电源微电网系统稳定性,以脉冲系统理论对微电网进行建模,为了提升微电网并网状态切换到孤岛状态时的稳定性,设计了一个两层的混合控制策略:第一层是由连续的本地控制器控制每个分布式电源,本地控制器的设计是基于李雅普洛夫理论的线性矩阵不等式技术,通过调整分布式电源子系统的设定点,使其达到最好的性能和合适的运行指数;第二层是通过分散监控控制进行协调,分散监控控制是建立在信息融合基础上,也就是使用广域测量系统,在有大的扰动情况下转换分布式电源子系统进入一个合适的运转状态。然后将前述的混合控制应用到一个10k V微电网中,研究了一个三相短路故障状态下微电网的暂态反应稳定性,通过simulink仿真,系统具有良好的暂态稳定性。
[Abstract]:In this paper, the hybrid system theory is applied to microgrid. Due to the large number of switching devices in microgrid, switching between continuous dynamic and discrete switching events is the behavior of microgrid. Therefore, microgrid is a typical hybrid system. In this paper, the hybrid control scheme is designed based on the theory of hybrid system, and the stability of microgrid is studied. Firstly, the research background and research progress of hybrid system theory, the purpose and significance of this paper, the concept and control method of microgrid and the basic knowledge of stability will be introduced. Secondly, the interval impulsive system theory is applied to the micro-grid. By defining the robust event exponent input to the state stability, the equivalent condition theorem for the robust event exponent input to the state stability is given. Applying the above results to interval impulsive systems, the exponential input stability of interval impulsive systems is defined, and the equivalent conditions for the exponential input of interval impulsive systems to state stability are given. Finally, the above results are applied to interval impulsive switched systems, and the equivalent conditions for robust exponential input to state stability of interval impulsive switched systems are given. According to the previous theory, if the restricted uncertainty matrix is in a small robust region, it will increase its attenuation rate, and input into the state stability theorem according to the exponent of interval impulsive switched system. This paper designs an interval pulse switching control system for VSC, and studies the input stability of micro-grid energy storage system under two external input conditions: load disturbance and islanding disturbance. In both cases, the system achieves input state stability. Finally, the stability of microgrid system with multiple distributed power sources is studied. In order to improve the stability of microgrid when switching to the isolated island state, the pulse system theory is used to model the microgrid. A two-layer hybrid control strategy is designed. In the first layer, each distributed power source is controlled by a continuous local controller. The design of the local controller is based on the linear matrix inequality (LMI) technique based on the Lyapunov theory. By adjusting the setting point of the distributed power subsystem to achieve the best performance and proper operation index, the second layer is coordinated by decentralized monitoring control, which is based on information fusion. In other words, the wide area measurement system is used to convert the distributed power subsystem into a suitable operation state under the condition of large disturbance. Then, the hybrid control is applied to a 10kV microgrid, and the transient stability of the microgrid under a three-phase short-circuit fault is studied. Through simulink simulation, the system has good transient stability.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM712

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