分布式光伏电站接入配电网优化规划研究

发布时间：2018-01-11 18:19

本文关键词：分布式光伏电站接入配电网优化规划研究　出处：《东南大学》2017年硕士论文　论文类型：学位论文

【摘要】：能源是国民经济发展和人民生活水平提高的重要物质保证。近年来,由于能源危机的爆发和环境污染的日趋严重,煤炭、石油等常规能源正逐步被新能源所替代。太阳能以其清洁、环境友好、不会枯竭的独特优势获得了极大关注。然而,太阳能的一大特点是它们具有随机性和不可控性,受天气因素影响较大,这对光伏电站并网规划设计工作提出了更高的要求。分布式接入方式能够最大限度利用太阳能资源,但导致配电网从单电源网络变成多电源网络,引起线路潮流方向的改变。因此,分布式光伏电站接入配电网的规划设计问题需要更加细致深入的研究。本文研究了光伏电站出力随机性模型,提出了对其进行随机模拟的方法;在建立光伏电站仿真模型的基础上,分析研究了光伏电站并网对配电网潮流分布、电压分布以及短路电流和继电保护等方面的影响;最后,本文提出了考虑光伏出力随机性的并网优化规划方法,对分布式光伏电站的并网位置和容量加以优化。具体研究内容如下:1、分析了太阳能的能源特性,建立了不同时间的地表光照强度计算模型,研究了在不同天气状态下地表光强随时间变化的分布特点。研究了光电转换模型,建立了以最大出力为基准值的归一化光伏电站出力的贝塔分布模型。提出了依据地区光照强度统计数据对贝塔分布概率密度函数参数估算,并进行随机模拟的方法。在实际算例中验证了该方法的有效性。2、研究了光伏电站并网对配电网的影响,基于此考虑光伏并网规划中需要关注的安全约束条件。通过分析推导,研究了光伏电站并网后线路潮流分布和节点电压分布的改变。分析了光伏电站短路电流的特性,研究了包含光伏电站的配电网在发生短路故障时线路的短路电流,以及与原有网络短路电流的差别,对继电保护系统正常运行可能带来的影响。在建立光伏电站物理仿真模型的基础上,在IEEE33典型配电网中接入该仿真模型进行模拟运行,研究了该仿真系统中电网的线路潮流的大小和方向、节点电压分布以及系统网络损耗等参数受光伏电站接入的影响。3、考虑光伏电站出力随机性特点,提出了一种光伏电站并网优化规划方法。优化设计光伏电站并网位置和相应容量,以降低对主电网的电能需求、减少碳排放为优化目标,保证断路器所在线路潮流方向不变,避免并网对继电保护装置的影响。改进了序贯蒙特卡洛模拟概率潮流计算方法,使之适应并网随机优化问题,并提高了计算效率。将优化约束以罚函数方式计入优化目标形成增广目标函数,并利用粒子群算法求解该优化问题。最后通过典型算例验证了该优化方法的优化效果。
[Abstract]:Energy is an important material guarantee for the development of national economy and the improvement of people's living standard. In recent years, because of the outbreak of energy crisis and the increasingly serious environmental pollution, coal. Conventional energy sources, such as oil, are gradually being replaced by new ones. Solar energy has received great attention because of its unique advantages of cleanliness, environmental friendliness, and undrying up. One of the characteristics of solar energy is their randomness and uncontrollability, which are greatly affected by weather factors. The distributed access mode can maximize the use of solar energy resources, but lead to the distribution network from a single power network to a multi-source network. Therefore, the planning and design of distributed photovoltaic power station access to distribution network needs more detailed and in-depth study. This paper studies the stochastic model of photovoltaic power generation. The method of random simulation is put forward. Based on the simulation model of photovoltaic power station, the influence of grid-connected photovoltaic power station on power flow distribution, voltage distribution, short-circuit current and relay protection is analyzed. Finally, this paper proposes a grid-connected optimal planning method to optimize the grid-connected position and capacity of distributed photovoltaic power plants considering the randomness of photovoltaic power. The specific research contents are as follows: 1. The energy characteristics of solar energy are analyzed, the surface light intensity calculation model at different time is established, the distribution characteristics of surface light intensity with time under different weather conditions are studied, and the photoelectric conversion model is studied. The beta distribution model of normalized photovoltaic power station based on the maximum output force is established, and the parameters of the beta distribution probability density function are estimated based on the regional light intensity statistics data. The effectiveness of the method is verified by a practical example. The effect of grid-connected photovoltaic power station on distribution network is studied. Based on this consideration of photovoltaic grid-connected planning needs to pay attention to the security constraints through analysis and derivation. The changes of power flow distribution and node voltage distribution in photovoltaic power station are studied, and the characteristics of short-circuit current in photovoltaic power station are analyzed. The short-circuit current of the distribution network including photovoltaic power station and the difference between the short-circuit current of the distribution network and the original network are studied. On the basis of establishing the physical simulation model of photovoltaic power station, the simulation model is connected to the typical distribution network of IEEE33 to simulate the operation. In this simulation system, the size and direction of line power flow, node voltage distribution and system network loss are affected by the access of photovoltaic power station. The randomness of photovoltaic power generation is considered. This paper presents an optimal planning method for grid-connected photovoltaic power plants. The optimal design of grid-connected position and corresponding capacity of photovoltaic power plants is aimed at reducing the power demand for the main power grid and reducing carbon emissions. The method of sequential Monte Carlo simulation probabilistic power flow calculation is improved to adapt to the stochastic optimization problem of grid connection. The optimization constraints are taken into account in the form of penalty function to form an augmented objective function. Particle swarm optimization algorithm is used to solve the optimization problem.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM715

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