独立光伏发电系统的MPPT及并网控制研究

发布时间：2018-03-06 06:31

本文选题：独立光伏发电系统　切入点：最大功率点跟踪　出处：《辽宁工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：光伏发电系统可以分为独立、并网、混合系统。其中，独立光伏发电系统具有转换环节最少、应用最直接、最经济等优点，，但自身也存在许多亟待解决的问题：光照强度和温度等环境条件的突变对光伏电池的输出功率影响较大；在一些光照充足的地方，额外的能量长期储存在蓄电池中，会造成一定量的浪费。设计一种专门针对独立光伏发电系统的，能够实现能量额外输出需求的“即插即用”的并网控制器，将有助于提高独立光伏发电系统的能量传输的灵活性。因此，对独立光伏发电系统的最大功率点跟踪及并网控制技术展开研究有一定的理论意义。本文从光伏发电的最大功率点跟踪控制技术、并网控制器的数学模型、并网控制策略三个方面展开研究。结合光伏电池等效电路及光照强度、温度等外界条件对光伏电池输出功率的影响，建立光伏电池的数学模型；对实现能量变换的逆变器拓扑结构进行分析，推导出相应的数学模型。基于最大功率点跟踪的工作原理，针对传统扰动观察法在兼顾跟踪精度和速度方面的不足，对扰动观察法加以改进，实现能快速稳定跟踪最大功率点的目标。并在Matlab/Simulink环境下搭建模型进行仿真分析，验证改进算法的有效性。对并网控制器的结构和工作原理进行分析，根据其拓扑结构建立暂态、稳态数学模型，并应用dq变换推导出并联侧、串联侧控制模型。依据并网控制器的并、串联侧控制模型，设计出并网控制策略及控制参数。在Matlab/Simulink环境下搭建出并网仿真模型，并对直接并网和采用并网控制器并网两种方式进行仿真分析，验证采用并网控制器能够实现独立光伏发电系统“即插即用”平滑快速并网的功能。
[Abstract]:Photovoltaic power generation systems can be divided into independent, grid-connected and hybrid systems. Among them, independent photovoltaic power generation systems have the advantages of minimum conversion links, most direct and economical applications, etc. However, there are many problems to be solved: the sudden changes in environmental conditions, such as light intensity and temperature, have a great impact on the output power of photovoltaic cells, and in some places where there is sufficient light, the extra energy is stored in the battery for a long time. Design a "plug and play" grid-connected controller designed specifically for stand-alone photovoltaic systems that can achieve additional energy output requirements. Therefore, the research on maximum power point tracking and grid-connected control technology of independent photovoltaic power generation system has certain theoretical significance. In this paper, the maximum power point tracking control technology of photovoltaic power generation, mathematical model of grid-connected controller and grid-connected control strategy are studied. The mathematical model of photovoltaic cell is established by the influence of temperature and other external conditions on the output power of photovoltaic cell. The topology of inverter is analyzed and the corresponding mathematical model is deduced. Based on the working principle of maximum power point tracking, the disturbance observation method is improved in view of the shortcomings of the traditional disturbance observation method in both tracking accuracy and speed. The aim of tracking the maximum power point quickly and stably is realized, and the simulation analysis is carried out under the environment of Matlab/Simulink to verify the effectiveness of the improved algorithm. The structure and working principle of grid-connected controller are analyzed, the transient and steady mathematical models are established according to its topology, and the control model of parallel side and series side is deduced by using dq transform. The series-side control model is used to design the grid-connected control strategy and control parameters. A grid-connected simulation model is built in Matlab/Simulink environment, and the direct grid-connected model and grid-connected controller are simulated and analyzed. It is verified that using grid-connected controller can realize the function of "plug and play" smooth and fast grid-connection of independent photovoltaic power generation system.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM615

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