微网中央控制器的设计及控制策略研究

发布时间：2018-10-25 15:49

【摘要】：微电网系统充分整合了各分布式电源的优势,削弱其对电力系统的不利影响,从而使分布式发电系统焕发活力。微电网系统区别于分布式发电系统的主要方面在于：微电网系统既可以脱离大电网孤岛运行,也可以结合大电网并网运行。故微电网系统在这两种模式下的控制以及两种模式间的平滑切换是保证微电网能够实现安全稳定运行的关键。本文针对微电网系统在孤岛运行模式、并网运行模式的电压与频率的控制、系统由孤岛切并网的预同步控制以及由并网且孤岛的控制进行了研究,主要内容如下：(1)首先介绍了微电网的产生与发展背景,对微电网的概念、特点以及各国微电网的发展现状进行了简单介绍；最后,对微电网系统的三种控制结构、四种控制策略进行了详细分析,并引出对应框图；(2)文中对双环逆变器电路进行结构分析,给出双环逆变器的等效电路；同时为实现孤岛模式下电压与频率的无差调节,本文采用二次调压／调频控制算法完成对给定值的跟踪;(3)文中对系统并网运行进行了分析,在传统下垂控制基础上提出一种改进方法,以维持输出功率恒定;最后针对系统离网到并网的平滑切换,提出并设计了预同步算法控制器,同时引出此过程中各单元分配系数公式；(4)将MGCC按系统通信机制、连接方式、组态界面等方面的要求进行设计,从而确保MGCC各项等功能的顺利实现；同时分别在Matlab/Simulink环境下和实验平台中对上述功能进行了仿真分析与实验验证,仿真与实验结果表明MGCC控制算法对微电网系统的有效性与可行性；
[Abstract]:The microgrid system fully integrates the advantages of the distributed generation and weakens its adverse influence on the power system, thus making the distributed generation system vibrant. The main difference between microgrid system and distributed generation system lies in that the microgrid system can be operated not only from the island of large power grid, but also combined with large grid. Therefore, the control of microgrid system in these two modes and the smooth switching between the two modes are the key to ensure the safe and stable operation of microgrid. In this paper, the control of voltage and frequency of microgrid system in islanding operation mode, grid-connected operation mode, pre-synchronous control of islanding and grid-connected system, and the control of grid-connected and isolated island are studied in this paper. The main contents are as follows: (1) the background of microgrid is introduced, the concept and characteristics of microgrid and the development status of microgrid in various countries are briefly introduced. Finally, three control structures of microgrid system are introduced. Four control strategies are analyzed in detail, and corresponding block diagrams are drawn. (2) the structure of double loop inverter circuit is analyzed in this paper, and the equivalent circuit of double loop inverter is given. At the same time, in order to realize the voltage and frequency regulation in isolated mode, In this paper, the quadratic voltage regulation / frequency modulation control algorithm is used to track the given value. (3) the system grid-connected operation is analyzed, and an improved method is proposed based on the traditional droop control to keep the output power constant. Finally, a presynchronization algorithm controller is proposed and designed for the smooth switching from the system off the grid to the grid-connected network. At the same time, the formula of the allocation coefficient of each unit in the process is derived. (4) the MGCC is connected according to the communication mechanism of the system and the connection mode. The requirements of the configuration interface are designed to ensure the smooth realization of the functions of MGCC. At the same time, the above functions are simulated and verified in the Matlab/Simulink environment and the experimental platform. Simulation and experimental results show the effectiveness and feasibility of MGCC control algorithm for microgrid systems.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM732

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