最大风能捕获改进爬山法研究

发布时间：2018-05-22 15:05

本文选题：爬山搜索算法 + 最佳叶尖速比法　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：风能的开发利用已受到世界各国的高度重视,最大风能捕获问题是风力发电系统中的关键问题之一。爬山法是实现最大风能捕获的常用方法,在实际应用中存在初始转速随机选择或经验选择、初始步长与步长变化靠经验选取等问题。本文围绕最大风能捕获问题,研究爬山法常见问题,改进最大风能捕获点搜索方法,实现找到最大风能捕获点。首先,对风力发电系统的特性进行分析,根据直驱式风力发电系统的原理及相关数学建模,采用Simulink仿真工具,建立了永磁风力发电系统的仿真模型。其次,针对爬山法初始角速度选取不确定问题,引入最佳叶尖速比法,给出了最佳叶尖速比爬山法,将最佳叶尖速比法获得的最佳角速度作为爬山法的起始角速度;在最佳叶尖速比法的基础上,针对爬山法初始步长选取问题,通过对使用最佳叶尖速比法得到的最佳角速度的误差分析,提出了自适应初始步长爬山法;仿真结果表明提出的自适应爬山法加快了搜索速度,改进了搜索效果。进一步通过对风能利用系数曲线的分析,根据在接近最大风能捕获点范围内的爬山搜索后期的特点,提出了自适应变比例因子爬山法。仿真结果分析表明,所提出的方法使系统在最大风能捕获点的震荡减小。最后,针对最佳叶尖速比法获得的初始爬山角速度与最佳角速度间误差较大问题,提出了模糊搜索算法,在最佳叶尖速比法的基础上,利用模糊搜索获取角速度误差修正量,得到与最佳角速度误差较小的爬山角速度初始值,此后利用第四章的改进爬山法搜索得到最佳角速度;在模糊控制器的设计方面,以风速以及风能利用系数曲线斜率为输入,由最佳叶尖速比法确定的爬山法初始加速度校正值为输出。由根据数据分析确定了输入输出量论域,利用最佳叶尖速比法误差大小与风速的关系、风能利用系数大小与最佳转速点误差的关系确定模糊规则;实验结果分析表明,所提方法进一步加快搜索速度与减小最大风能捕获点处的震荡。
[Abstract]:The development and utilization of wind energy has been attached great importance in the world, and the problem of maximum wind energy capture is one of the key problems in wind power generation system. Mountain climbing method is a commonly used method to realize maximum wind energy capture. In practical application there are some problems such as random or empirical selection of initial rotational speed and the change of initial step size and step size depending on experience selection and so on. This paper focuses on the problem of maximum wind energy capture, studies the common problems of mountain climbing method, improves the search method of maximum wind energy capture point, and realizes finding the maximum wind energy capture point. Firstly, the characteristics of wind power system are analyzed. According to the principle of direct-drive wind power system and related mathematical modeling, the simulation model of permanent magnet wind power generation system is established by using Simulink simulation tool. Secondly, aiming at the uncertainty of the initial angular velocity of mountain climbing method, the optimal tip speed ratio method is introduced, and the best angle velocity obtained by the best blade tip velocity ratio method is taken as the starting angle velocity of the mountain climbing method. On the basis of the optimal tip speed ratio method, an adaptive initial step climbing method is proposed by analyzing the error of the optimal angular velocity obtained by using the optimum tip speed ratio method, aiming at the selection of the initial step size of the mountain climbing method. The simulation results show that the proposed adaptive mountain climbing method accelerates the search speed and improves the search effect. Based on the analysis of wind energy utilization coefficient curve and the characteristics of mountain climbing near the maximum wind energy capture point, an adaptive variable scale factor climbing method is proposed. The simulation results show that the proposed method can reduce the oscillation at the maximum wind energy capture point. Finally, a fuzzy search algorithm is proposed to solve the problem that the error between the initial climbing speed and the optimal angular velocity obtained by the best blade tip speed ratio method. Based on the optimum blade tip velocity ratio method, the angle velocity error correction quantity is obtained by using the fuzzy search method. The initial value of the angular velocity of mountain climbing with small error of the optimal angular velocity is obtained, and the optimum angular velocity is obtained by using the improved climbing method in Chapter 4. In the design of the fuzzy controller, the slope of the wind speed and the wind energy utilization coefficient curve is taken as the input. The correction value of the initial acceleration of the mountain climbing method determined by the optimum blade tip velocity ratio method is output. According to the data analysis, the input-output range is determined. The fuzzy rules are determined by using the relationship between the error of the best tip speed ratio method and the wind speed, and the relationship between the wind energy utilization coefficient and the error of the best rotational speed point. The proposed method further speeds up the search speed and reduces the oscillation at the maximum wind energy capture point.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614

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