【作者】 高春凤；

【导师】 杨仁刚；

【作者基本信息】 中国农业大学 ， 农业电气化与自动化， 2014， 博士

【摘要】 随着全球人口的增长、能耗的增加、环境问题的严峻和化石能源的逐步枯竭,可再生能源的开发利用得到越来越多的关注。微电网作为一种整合利用分布式电源的有效形式,如何通过灵活的控制技术实现可再生能源的充分利用,提高供电质量与可靠性成为研究的热点。此外,微电网的分布式特性越来越明显,渗透率正逐渐提高,在高渗透率情况下如何有效地控制多个微电网的运行成为亟待解决的问题。本文围绕微网群协调控制涉及的发电单元控制、微电网控制、群级控制以及控制通信系统模型等几个方面展开了深入的研究,主要研究成果如下：1)针对分布式电源下垂控制中频率存在偏差的问题,提出了基于虚拟频率的下垂控制方法。该方法给出通过改变虚拟频率设定值来调整相角,得到相角下垂控制系数,实现了在不改变电源频率条件下的无功功率输出。仿真实验结果表明,与以往下垂控制方法相比基于虚拟频率的下垂控制方法无需改变频率设定值即可实现相同功率分配效果。2)针对微电网多运行状态、分布式电源多控制模式的问题,建立了基于有限状态机矩阵的状态转换模型,提出了基于有限状态机矩阵的微电网协调控制方法。该方法可以实现微电网全局控制管理,并且在离网独立运行状态下通过分区协调控制实现了电压频率的二次调整和功率越限控制。3)提出了确定微电网在群体中对外应表现的控制特性指标及实现外特性的控制方法,并给出了基于该控制方法的微网群协调控制3层体系结构。通过仿真实验验证了评价指标及其控制方法的适用性和合理性。4)在对微电网功能进行全面分解组合的基础上,建立了IEC61850微电网通信控制信息模型,并给出了基于该信息模型的微网群控制实现方法。该信息模型为微网群中智能设备互操作提供了基础,使得微电网控制方法实现过程标准化,文中对典型控制功能的实现进行了验证。更多还原

【Abstract】 Along with growth of the world’s population, increased consumption of energy, serious environmental problems and exhaustibility of fossil fuels, the development and utilization of renewable energy attracts much more attention. Micro-grid is an effective way to support distributed generation integrated into, it has become a hot topic that how to make full use of renewable energy, improve power quality and guarantee reliability of power supplement through flexible control technology. Moreover, due to distributed characteristics and permeability of micro-grid increasing gradually, how to effectively control multi-microgrids operation becomes a serious problem that needs to be solved urgently.This paper mainly studies in coordinated control of a micro-grid cluster, which involves control of a power generation unit, control of a micro-grid and control of a micro-grid cluster. The main results of this research are as follows:1) Aim at the frequency deviation problem existing in droop control of distributed generation, an improved droop control method based on virtual frequency is proposed. In this method, adjustment of phase angle is achieved by changing setting value of virtual frequency, and then can get the control coefficient of voltage phase-angle droop. Consequently, reactive power output is achieved in the condition of not changing frequency of distributed generation. Simulations results show that, compared with previous droop control method, when the same effect of power allocation is done, the proposed droop control method based on virtual frequency need not change setting value of frequency.2) Concentrate on problem existing in multiple operation states of micro-grid and multiple control modes of distributed generation, a coordinating control method based on finite-state-machine matrix is presented. The control method can provide global control and management for overall micro-grid. Also, in the condition of off-grid operation, secondary adjustment of voltage and frequency as well as power over-limit control can be achieved through partition coordination and control.3) Not only a method to define the external control characteristic indexes that a micro-grid shows in the micro-grid cluster but also a method to realize the control of external characteristic of a micro-grid are proposed. Furthermore, a three-layer coordinated control architecture of micro-grid cluster is given, which is based on the control method mentioned above. Simulations are carried out to demonstrate the applicability and rationality of the indicator and this method.4) Based on functional decomposition and integration of the micro-grid, a control information model on the grounds of IEC61850communication protocol is established, then providing a control method used this information model to achieved3-layer control of the micro-grid cluster. The information model provides basis for interoperations between different intelligent devices and makes the process of the micro-grid control standardized. Also, typical control functions are tested and proven in the paper.更多还原