光伏发电微逆变器的研究

发布时间：2018-04-25 00:03

本文选题：光伏发电 + 微逆变器　；参考：《北京交通大学》2014年硕士论文

【摘要】：当今世界,能源危机和环境污染问题越来越突出。为实现可持续发展战略目标,清洁、可再生能源的开发、利用越来越受到人类关注。太阳能因其取之不尽、清洁无污染,被公认为是最理想的可再生能源之一。光伏并网逆变器是光伏电池板和电网连接的转换设备,是光伏发电系统的关键,逆变器的性能、效率直接影响着光伏发电系统的整体效率。本文研究的光伏微逆变器是将单个光伏电池板输出的小功率的直流低电压转化为高电压交流并网的转换装置。并实现对单个光伏电池板最大功率跟踪,避免了大规模光伏阵列因为局部损坏或是被遮蔽时对整体效率的影响,有效提高了光伏系统整体的安全性、可靠性、高效性。本文首先总结了微逆变器常用的拓扑结构及其各自优缺点,分析了微逆变器的优点及其设计要点,得出微逆变器设计的关键技术之一在于DC/DC升压电路的选取。另外,降低电容容值,提高微逆变器的寿命是微逆变器设计中另一个关键技术。其次,分析了本文所采用的nX型DC/DC变换器的研究基础,随后对nX型DC/DC升压变换器的工作原理进行了详细分析,并完成了基于MATLABTM/SIMULINK软件平台的仿真验证和基于DSP开发板的实验验证；根据光伏电池的输出特性方程,搭建了仿真模型,并验证了光伏电池板的I-V、P.V输出特性；在此基础上,设计了MPPT控制算法、单相并网控制策略和孤岛检测等,其中最大功率点跟踪采用的是不等步长的扰动观测控制法,能准确迅速的追踪光伏电池板最大功率点并提高系统稳定性；并网电流控制采用准比例谐振控制方法,能有效消除并网过程中电网电压扰动所带来的干扰,简化控制算法,优化并网电流输出波形；孤岛检测采用被动式的欠／过压策略。根据控制策略以及系统的工作原理,推导了nX型DC/DC变换器和滤波电路的器件参数的选取依据；利用MATLABTM/SIMULINK软件平台对本文中的nX型微逆变器拓扑运行特性进行了大量仿真,验证了拓扑设计的合理性和控制方法的有效性。最后,完成了在CCS3.3环境中的软件设计。
[Abstract]:Nowadays, energy crisis and environmental pollution are more and more prominent in the world. In order to achieve the strategic goal of sustainable development, clean, renewable energy development, the use of more and more attention. Solar energy is recognized as one of the most ideal renewable energy because of its inexhaustible, clean and pollution-free. Photovoltaic grid-connected inverter is the conversion equipment connected with PV panels and grid, and is the key of photovoltaic power generation system. The performance and efficiency of the inverter directly affect the overall efficiency of photovoltaic power generation system. The photovoltaic micro-inverter studied in this paper is a conversion device which converts the low-power DC voltage from a single photovoltaic panel to a high-voltage AC grid-connected device. The maximum power tracking of a single photovoltaic panel is realized to avoid the impact of large-scale photovoltaic arrays on the overall efficiency due to local damage or obscuration, and the overall security, reliability and efficiency of the photovoltaic system are effectively improved. In this paper, the common topology of microinverters and their advantages and disadvantages are summarized, and the advantages and disadvantages of microinverters are analyzed. The selection of DC/DC boost circuit is one of the key techniques in the design of microinverters. In addition, reducing capacitance and improving the life of micro inverter is another key technology in the design of micro inverter. Secondly, the research foundation of nX type DC/DC converter used in this paper is analyzed, then the working principle of nX type DC/DC boost converter is analyzed in detail, and the simulation verification based on MATLABTM/SIMULINK software platform and the experiment verification based on DSP development board are completed. According to the output characteristic equation of photovoltaic cell, the simulation model is built, and the output characteristic of I-VPV is verified. On this basis, the MPPT control algorithm, single-phase grid-connected control strategy and islanding detection are designed. The maximum power point tracking is based on the disturbance observation control method with unequal step size, which can accurately and rapidly track the maximum power point of the photovoltaic panel and improve the stability of the system, while the grid-connected current control adopts the quasi-proportional resonance control method. It can effectively eliminate the disturbance caused by the voltage disturbance, simplify the control algorithm, optimize the output waveform of grid-connected current, and use passive under-/ over-voltage strategy in islanding detection. According to the control strategy and the working principle of the system, the selection basis of the device parameters of the nX-type DC/DC converter and filter circuit is deduced, and the topology operation characteristics of the nX-type micro-inverter in this paper are simulated by using the MATLABTM/SIMULINK software platform. The rationality of the topology design and the effectiveness of the control method are verified. Finally, the software design in CCS3.3 environment is completed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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