直驱式永磁风力发电系统最大功率跟踪研究

发布时间：2018-11-14 17:47

【摘要】：环境污染问题的日益突出,地球上化石能源的急剧减少,使得我们必须大力发展清洁可再生能源。风电以其清洁、无污染、建设周期短、运营成本低等优点,现已成为能源行业的重点领域;在所有风力发电机组中,直驱式永磁风力发电系统以其高效率低故障的特牲得到了迅速的发展。首先,本文介绍了风力发电的技术背景和国内外的发展现状,并给出了离网型直驱式永磁风力发电系统的结构。论述了风力发电的理论基础,阐述了坐标变换基本原理并给出了永磁同步发电机的数学模型,详细分析各种斩波电路的原理及特点,为后面分析最大功率追踪的原理和建立模型奠定了基础。其次,重点研究了直驱式永磁风力发电系统的最大功率跟踪原理,给出了最大功率跟踪与占空比的关系。介绍了最大功率的两种调节方式,进而对比研究了几种常用的最大功率跟踪方法,最佳叶尖速比法、功率反馈法以及爬山搜索法。随后,具体分析研究了基于BOOST电路的爬山搜索法,针对传统的爬山搜索法和梯度式变步长爬山搜索法存在的不足,提出了改进的梯度式变步长爬山搜索算法。最后,在MATLAB/Simulink平台上搭建了小型离网直驱式永磁风力发电系统的最大功率仿真模型以及组合风速仿真模型,仿真输出了风力机的特性曲线和组合风速曲线。从组合风速曲线可以看出该模型仿真出了风速的随机性、渐变性、突变性等特点,并对改进前和改进后的爬山搜索法进行了对比,结果表明:改进的梯度式变步长爬山搜索法不但能够快速地追踪到最大功率点,而且具有很高的准确性。
[Abstract]:The problem of environmental pollution is becoming more and more serious, and the fossil energy on the earth is decreasing rapidly, so we must develop clean and renewable energy. Wind power has become the key field of energy industry because of its advantages of clean, pollution-free, short construction period, low operating cost and so on. Among all wind turbines, direct-drive permanent magnet wind power generation system has been developed rapidly because of its high efficiency and low fault. Firstly, this paper introduces the technical background of wind power generation and the development situation at home and abroad, and gives the structure of off-grid direct-drive permanent magnet wind power generation system. This paper discusses the theoretical basis of wind power generation, expounds the basic principle of coordinate transformation, gives the mathematical model of permanent magnet synchronous generator, and analyzes in detail the principle and characteristics of various chopping circuits. It lays a foundation for the analysis of the principle of maximum power tracing and the establishment of model. Secondly, the principle of maximum power tracking for direct-drive permanent magnet wind power generation system is studied, and the relationship between maximum power tracking and duty cycle is given. This paper introduces two ways of regulating the maximum power, and then compares and studies several commonly used maximum power tracking methods, the best tip speed ratio method, the power feedback method and the mountain climbing search method. Then, the mountain climbing method based on BOOST circuit is analyzed and studied in detail. Aiming at the shortcomings of traditional mountain climbing search method and gradient variable step size mountain climbing search method, an improved gradient variable step size mountain climbing algorithm is proposed. Finally, the maximum power simulation model and the combined wind speed simulation model of the small off-grid direct-drive permanent magnet wind power generation system are built on the MATLAB/Simulink platform. The characteristic curve and the combined wind speed curve of the wind turbine are simulated and outputted. It can be seen from the combined wind speed curve that the model simulates the randomness, gradual variation and mutation of wind speed, and compares the improved mountain climbing search method before and after the improvement. The results show that the improved gradient variable step size mountain climbing search method can not only track the maximum power points quickly, but also have high accuracy.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614

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