基于可变系数的双馈风电机组与同步发电机协调调频策略

发布时间：2018-07-27 20:30

【摘要】：随着能源危机和环境问题日益严峻,风电作为清洁的可再生能源在全球范围内得到了前所未有的关注。在我国风能资源丰富的地区,风电的渗透率已经超过20%,随着风电装机容量的不断增大以及渗透率的不断提高,大规模风电并网对电网的频率安全影响日益显现。双馈感应风力发电机组(DFIG,Doubly-FedInductionGenetator)已经成为现役主流机型,但是其转子转速与电网频率解耦的控制方式决定了其输出的有功功率无法响应电网的频率变化,当风电的渗透率不断升高时,电网的调频压力不断增大。因此,研究双馈风电机组的调频技术以及与同步发电机之间的协调调频策略具有重要意义。本文主要以双馈风电机组的调频控制策略为主要内容,在现有文献综述的基础上,研究双馈风电机组的调频技术。首先概述了国内外风电的发展历史和趋势,分析了现有风电技术快速发展过程中应该注意的问题,并对风电调频的相关技术做了综述。结合同步发电机的频率响应特性,对双馈风电机组的模拟惯量特性进行了理论上的分析。研究了双馈风电机组的模拟惯量控制,对模拟惯量控制的理论部分进行了介绍,给出了相关的控制框图,对传统的桨距角控制方式进行了改进,使其也具备了频率响应能力,并对双馈风电机组与同步发电机的频率特性作了比较。本文也分析了风电机组现有的定系数调频的不足之处,进一步给出根据风电场中每台风电机组的当前风速不断优化其调差系数的调频策略,使得风电场中的调频功率可以合理地分配。针对风电作为一种新的调频电源并入电网时,对双馈风电机组与同步发电机的协调控制理论进行了推导,在不同的风速段根据双馈风电机组的不同运行方式,定义了调频时的可变调差系数,并制定了相关的协调调频策略,仿真部分基于MATLAB/SIMULINK进行了仿真分析,仿真结果表明,所给出的可变系数调频策略有利于平滑风电场的风电功率波动,可使双馈风电机组的储备功率更加充分地参与调频,并有效减轻同步发电机的调频压力。
[Abstract]:With the increasingly serious energy crisis and environmental problems, wind power as a clean renewable energy in the world has received unprecedented attention. In the region rich in wind energy resources, the permeability of wind power has exceeded 20%. With the increasing of installed capacity and permeability of wind power, the influence of large-scale wind power grid on frequency security is becoming more and more obvious. The doubly-fed induction Genetator (DFIGG) has become the mainstream model in active service, but its rotor speed decoupling with the frequency of the power grid determines that the active power output can not respond to the frequency change of the power grid. When the wind power permeability is increasing, The FM pressure of the power grid is increasing. Therefore, it is of great significance to study the FM technology of doubly-fed wind turbine and the coordinated FM strategy with synchronous generator. In this paper, the FM control strategy of doubly-fed wind turbine is taken as the main content. Based on the literature review, the FM technology of doubly-fed wind turbine is studied. Firstly, the development history and trend of wind power at home and abroad are summarized, the problems that should be paid attention to in the rapid development of existing wind power technology are analyzed, and the related technologies of wind power FM are summarized. Combined with the frequency response characteristics of synchronous generator, the simulation inertia characteristics of doubly-fed wind turbine are analyzed theoretically. The simulation inertia control of doubly-fed wind turbine is studied, the theoretical part of the simulation inertia control is introduced, the relevant control block diagram is given, and the traditional control mode of pitch angle is improved to make it have the ability of frequency response. The frequency characteristics of doubly-fed wind turbine and synchronous generator are compared. This paper also analyzes the shortcomings of the existing fixed coefficient frequency modulation (FM) of wind turbine units, and further gives the FM strategy to optimize the difference coefficient according to the current wind speed of each wind turbine in the wind farm. The frequency modulation power in the wind farm can be reasonably distributed. When wind power is incorporated into power network as a new FM power supply, the coordinated control theory between doubly-fed wind turbine and synchronous generator is deduced, and different operation modes of doubly-fed wind turbine are given in different wind speed sections. The variable difference coefficient of frequency modulation is defined, and the corresponding coordinated frequency modulation strategy is worked out. The simulation part is based on MATLAB/SIMULINK. The simulation results show that, The proposed variable coefficient frequency modulation strategy is beneficial to smooth the fluctuation of wind power in wind farm, make the reserve power of doubly-fed wind turbine more fully participate in frequency modulation, and effectively reduce the frequency modulation pressure of synchronous generator.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614

【参考文献】