基于电能质量态势感知的分布式电源主动运行决策方法

发布时间：2018-09-19 13:29

【摘要】：常规能源的不断枯竭导致以风能、光伏等可再生能源发电的DG技术得到了迅速的发展。而DG并入电网渗透率过高时,会影响电网的可靠与稳定运行。目前对电能质量问题的研究基本上都采用先发后治的策略,无法保证微电网的持续稳定运行。微电网并网变流器的出现能实现电能质量问题的跟踪补偿,是保障微电网安全稳定运行的一种手段。基于此,本文提出将并网变流器升级为具有态势感知和态势利导功能的先进变流器,对涉及电能质量变化的各类信息元素进行采集、理解与预测,力求及时准确地掌握所需要素信息的变化态势,通过变化态势的呈现,再对微电网电能质量的控制决策进行有利方向的引导,从而可实现动态灵活调整和控制。为实现微网系统电能质量态势感知与微网变流器主动运行决策,本文研究了IEC61850 90-7标准,OpenADR通信规范、需求响应技术、马尔科夫决策过程以及微网潮流计算、奇异值分解等相关知识。基于需求响应技术与微网潮流计算等知识能从不同角度实现对微电网电能质量的变化态势进行感知;基于马尔科夫决策过程的建模方法是采用动态规划的思想,通过确定变流器主动运行中的状态、行为、状态转移概率矩阵和收益矩阵来实现对决策过程建模;基于IEC 61850 90-7标准的分布式系统的信息建模方法可使得微网系统中各设备具有自描述能力,满足系统各设备之间的互操作。以上述技术为基础,本文提出了两种分布式发电主动运行决策方法,分别从基于电网电价以及微网潮流两个角度去研究。前者通过对电网发布电价进行分析、理解以实现对微网电能质量的需求状态的感知,后者通过微网连续潮流计算的以及奇异值分解法实现对微网电能质量的需求状态的感知;前者是通过马尔科夫决策过程模型实现分布式发电变流器运行模式最优决策,而后者是提出了两个阶段的分布式发电主动运行决策,第一阶段是基于奇异值分解的方法实现对微网的潮流Jacobian矩阵分解,找到电压薄弱节点,来通过变流器的运行决策实现对电压薄弱节点的调节;第二阶段是基于微网潮流预测所得电能质量需求信息,变流器基于马尔科夫决策过程进行运行模式的决策。
[Abstract]:The depletion of conventional energy has led to the rapid development of DG technology which uses renewable energy, such as wind energy and photovoltaic. When the permeability of DG is too high, the reliable and stable operation of power grid will be affected. At present, the research on power quality is based on the strategy of first sending and then treating, which can not guarantee the continuous and stable operation of microgrid. The appearance of microgrid grid-connected converter can realize the tracking compensation of power quality problem and is a means to ensure the safe and stable operation of microgrid. Based on this, this paper proposes to upgrade the grid-connected converter to an advanced converter with situational awareness and situational guidance, and to collect, understand and predict all kinds of information elements related to the change of power quality. This paper tries to grasp the change situation of the required element information in time and accurately, through the presentation of the change situation, and then guide the power quality control decision of microgrid in a favorable direction, so that the dynamic and flexible adjustment and control can be realized. In order to realize the situation perception of power quality and the active operation decision of microgrid converter, the communication specification, demand response technology, Markov decision process and micro-grid power flow calculation of IEC61850 90-7 standard are studied in this paper. Singular value decomposition and other related knowledge. Based on the knowledge of demand response technology and micro-grid power flow calculation, the change situation of power quality of micro-grid can be perceived from different angles, and the modeling method based on Markov decision-making process is based on the idea of dynamic programming. The decision-making process is modeled by determining the state, behavior, state transition probability matrix and income matrix in the active operation of the converter. The information modeling method of distributed system based on IEC 61850 90-7 standard can make each device in microgrid system have self-description ability to satisfy the interoperability among the devices in the system. Based on the above technology, this paper presents two kinds of distributed generation active operation decision methods, which are studied from two aspects of grid price and micro-grid power flow respectively. The former realizes the perception of the demand state of the micro-grid power quality through the analysis of the electricity price released by the grid, and the latter realizes the perception of the demand state of the micro-grid power quality by the micro-grid continuous power flow calculation and the singular value decomposition method. The former uses Markov decision process model to realize the optimal decision of distributed power converter operation mode, while the latter puts forward two stages of distributed generation active operation decision. The first stage is to realize the power flow Jacobian matrix decomposition of the microgrid based on singular value decomposition (SVD) and find the weak voltage node to adjust the voltage weak node through the operation decision of the converter. The second stage is based on the power quality information obtained from the micro-grid power flow prediction, and the converter is based on Markov decision-making process to make the decision of the operation mode.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM732

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