摘要风机在低于额定风速下运行时,会采用最大功率点跟踪控制(MPPT)。随着风机大型化的发展趋势。对风电机组MPPT控制策略的优化过程中,需要考虑湍流风速的影响,涉及平均风速、湍流强度和湍流频率等主要指标。其中湍流频率的分析普遍采用功率谱的方法,由于湍流风速中包含很多频率分量,所以用功率谱表示的湍流风速无法直接描述其频率的大小。这给不同湍流风速的频率比较带来了困难。
本文基于GH-bladed专业风机仿真软件,分析了湍流风速、湍流强度以及湍流频率对于MPPT控制的影响。在湍流风速频率的比较方法上,采用了目前提出的功率谱密度曲线在定义频段蕴含的平均功率的比较方法,和采用风速变化分量在定步长下的平均变化速率的比较方法。对构造的湍流风,得出了湍流风速频率对传统功率曲线法风机的MPPT控制的影响。19148
关键词 风机 湍流风速 MPPT控制 湍流风频率 功率谱
毕业论文设计说明书(论文)外文摘要
Title Research on the Effects of Turbulence Frequency on Maximum Power Point Tracking Control of Wind Turbine
Abstract
At present, maximum power point tracking control(MPPT) is used in wind energy conversion systems, which will control the turbine to extract the available power from the wind. With the development of wind energy industry, the effects of turbulent wind speed on MPPT control should be taken into consideration in the optimization procedure of the control method. The three major indicators of turbulent wind speed are mean wind speed, turbulence intensity and turbulence frequency. Power spectrum is generally applied to analyzing the frequency of turbulent wind. However, the numerical size of the frequency of a turbulent wind profile described by power spectrum cannot be directly obtained due to the fact that there are many different components contained in turbulence frequency, which makes it difficult to compare the frequencies of different turbulent wind speeds.
The effects of turbulent wind speed, turbulence intensity and turbulence frequency on MPPT control are compared in this thesis utilizing the professional simulation software GH Bladed. The mean power contained in the frequency band defined by power spectrum density function and the ratio of wind speed variation at constant step are used in turbulence frequency comparison. Finally, the effects of turbulence frequency on wind turbine controlled by conventional power signal feedback method are verified by generated turbulence.
Keywords wind turbine; turbulent wind speed; maximum power point tracking; turbulence frequency; power spectrum
目 次
1 引言 1
1.1 风能的发展趋势 1
1.2 MPPT控制的现状和问题 1
1.3 本论文的主要工作 2
2 仿真软件 3
2.1 GH-bladed简介 3
2.2 GH-bladed与Matlab的仿真关联 4
3 风机的数学模型 5
3.1 湍流风的建模 5
3.2 空气动力学模型 9
3.3最大功率点跟踪控制理论 13
3.4 湍流风速对MPPT控制的影响分析 15
4 湍流风速对MPPT控制的影响 17
4.1 生成仿真湍流风速 17
4.2 计算仿真及结果 18
4.3 湍流风速对于MPPT影响的小结 23
5 基于周期风速频率的影响 24
5.1 构造同湍流强度不同频率的周期风 24
5.2 构造的周期风对MPPT的影响 25
6 湍流风速频率的比较 27 GH-bladed湍流风速频率对于风电机组MPPT控制的影响分析:http://www.youerw.com/zidonghua/lunwen_10395.html