大型光伏电站并网特性及其控制技术研究

发布时间：2018-01-16 09:47

本文关键词：大型光伏电站并网特性及其控制技术研究　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着因化石燃料过度消耗而产生的温室效应成为了全球关注的焦点,我国正在大力推广利用太阳能等可再生清洁能源的发电技术。本论文首先简述了光伏发电的原理,介绍了光伏发电的优势及发展方向,阐述了国内外光伏发电技术及光伏并网技术的发展现状及前景。鉴于光伏发电出力的随机性和不连续性,最大功率点跟踪技术(MPPT)一直都是研究重点,随着光伏发电技术的发展,MPPT也为了满足新的要求而不断发展,以提高系统稳定性并且适应各种运行条件。光伏电站并入电网运行会对电网多方面造成影响,例如孤岛效应、谐波污染问题、无功补偿问题,电压闪变的问题,本文总结了一些目前用于解决这些问题的方法。逆变器是光伏并网发电的关键技术,在这方面,本文叙述了并网逆变器的功能,拓扑结构的发展、有待解决的问题以及大型光伏电站并网逆变器的发展趋势。根据目前发展形势可知,光伏发电的并网化和大型化是将来的主要发展趋势,提高光伏发电效率,增加并网容量,都有助于发展低碳电网。由于光伏发电的随机性强,所以本文通过MATLAB/SIMULNIK建造光伏电站的模型,根据真实的环境数据得出一年中的典型日的光伏发电输出特性曲线,并进行了对比分析,随后还提出了一种大型光伏电站的低碳调度,也是一种最优调度。另一方面,随着光伏电站的容量不断增加,并网时需要考虑更多的负面影响,而且还要达到低碳运行的标准,这都对并网逆变器提出了许多新的要求,所以本论文设计出了一种具有MPPT控制、无功及谐波电流补偿以及有功控制相结合的大型光伏电站并网逆变器的多模式控制策略,最后通过MATLAB/SIMULNK建模仿真验证了该逆变器控制策略的可行性及优点。本文还研究了大型光伏电站集中式并网发电的情况,应用混合型储能系统,使得光伏电站始终向电网输送稳定的电能以进行统一调度,而不是直接向负荷供电。选用由电池和超级电容组合而成混合型储能系统,并提出合适的控制策略以在提供充足电能的同时维持直流公共环节的电压值。选取两组连续的环境数据进行建模仿真,仿真结果验证了控制策略的正确性,为大型光伏电站并网发电提供了理论依据。
[Abstract]:With the greenhouse effect caused by excessive consumption of fossil fuels has become the focus of global attention, China is vigorously promoting the use of solar energy and other renewable clean energy generation technology. In this paper, the principle of photovoltaic power generation is introduced, and the advantages and development direction of photovoltaic power generation are introduced. The development status and prospect of photovoltaic generation technology and photovoltaic grid-connected technology at home and abroad are described. In view of the randomness and discontinuity of photovoltaic power generation, maximum power point tracking technology (MPPTT) has always been the focus of research. With the development of photovoltaic power generation technology, MPPT is also developing to meet the new requirements. In order to improve the stability of the system and adapt to various operating conditions. Photovoltaic power plants incorporated into the grid operation will have many impacts on the grid, such as islanding effect, harmonic pollution, reactive power compensation, voltage flicker. In this paper, some methods used to solve these problems are summarized. Inverter is the key technology of grid-connected photovoltaic power generation. In this respect, the function and topology of grid-connected inverter are described. The problems to be solved and the development trend of grid-connected inverters for large photovoltaic power stations. According to the current development situation, grid-connected and large-scale photovoltaic power generation is the main development trend in the future, improve the efficiency of photovoltaic power generation, increase grid-connected capacity. Because of the strong randomness of photovoltaic power generation, this paper builds the model of photovoltaic power station through MATLAB/SIMULNIK. According to the real environmental data, the output characteristic curves of photovoltaic power generation in typical days of one year are obtained and compared and analyzed. Then, a low carbon scheduling of large photovoltaic power plants is proposed, which is also an optimal scheduling. On the other hand, with the continuous increase of the capacity of photovoltaic power plants, the grid connection needs to consider more negative effects, and also to meet the standards of low-carbon operation, which put forward a lot of new requirements for grid-connected inverters. Therefore, this paper designs a multi-mode control strategy for grid-connected inverter of photovoltaic power station with MPPT control, reactive power and harmonic current compensation and active power control. Finally, the feasibility and advantages of the inverter control strategy are verified by MATLAB/SIMULNK modeling and simulation. This paper also studies the situation of centralized grid-connected power generation in large-scale photovoltaic power plants. The hybrid energy storage system is used to make the photovoltaic power station always transmit stable electric energy to the power grid for unified dispatching. Instead of supplying power directly to the load, a hybrid energy storage system consisting of batteries and super capacitors is chosen. An appropriate control strategy is proposed to maintain the voltage of the DC common link while providing sufficient power. Two groups of continuous environmental data are selected for modeling and simulation. The simulation results verify the correctness of the control strategy. It provides a theoretical basis for grid-connected power generation of large photovoltaic power plants.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM615

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