【作者】 王文博；

【导师】 邹云；

【作者基本信息】 南京理工大学 ， 电气工程（专业学位）， 2021， 硕士

【摘要】 随着电网中风电渗透率的不断提高,风电功率的随机性和波动性给电力系统频率稳定带来的影响不容忽视。为缓解大规模风电并网对电力系统造成的调频负担,风电机组需要改变传统的发电效益最大化模式,转为参与电网的自动发电控制(AGC),这使得风机的机电动态调节更加依赖变桨。但研究发现,传统PI变桨控制很难在不同运行条件下都表现出较好的转速调节效果,因此迫切需要对风机的变桨控制性能进行改进。现有关于风机变桨控制的研究,主要是通过对变桨控制器的改进使风机系统更快地响应风速和功率指令的变化,从而减小风轮转速的波动程度。然而,现有改进策略缺乏考虑执行器对控制器指令的执行能力,也就是缺乏考虑变桨执行机构的实际运行限制。这会给变桨控制性能带来各种不利影响,最主要的就是积分饱和现象。积分饱和现象在风速剧烈波动时会恶化风机的转速调节性能,因此风机变桨控制性能的改进需要考虑积分饱和的影响。本文基于对变桨执行机构实际运行限制的考虑,应用补偿式抗积分饱和方法,设计了适用于风机系统的抗饱和变桨控制器,主要研究成果如下:(1)分析了风机变桨控制中积分饱和现象的产生机理,提出了饱和程度的评价指标。首先对风机变桨控制中的幅值饱和与速率饱和现象进行介绍,指出二者之间的区别和联系。其次基于灵敏度的比较,对速率饱和的产生机理进行探究。最后提出了饱和程度的评价指标,分析了不同饱和程度对变桨控制性能的影响。(2)基于补偿式抗饱和方法,设计了适用于风机系统的抗饱和变桨控制器。改进了补偿结构,利用等效惯性环节的设计避免了变桨执行机构的惯性对抗饱和控制器性能的不利影响;提出了补偿系数的设定方法,基于自适应算法给定了补偿系数的取值规则。(3)基于FAST软件和风机动模实验系统对本文提出的抗饱和变桨控制方法进行了有效性验证。仿真和实验结果表明,相比于其他控制算法,本文的改进方法能够表现出较好的转速调节性能。更多还原

【Abstract】 With the continually growing penetration rate of wind power in the power grid,randomness and volatility characteristics of wind power have brought about considerable negative impacts on power system frequency stability.In order to alleviate the frequency regulation burden caused by the integration of large-scale wind power in the power grid,it is necessary for wind turbines to transform from traditional maximum power generation benefit mode to participating in the automatic generation control(AGC)of the power grid,which makes the electromechanical dynamics adjustment of wind turbines more dependent on pitch angle control.However,studies have found that it is difficult for the traditional PI pitch control to behave well in rotating speed regulation under different operating conditions,so there is an urgent need for the wind turbines to improve the performance of pitch angle control.The existing research on wind turbine pitch angle control is mainly to make the wind turbine system respond faster to changes in wind speed and power command through the improvement of the pitch angle controller.However,this kind of improvement strategies doesn’t take the pitch actuator’s ability to execute the controller’s instructions into account,that is,shows less consideration of actual operating limitations of the pitch actuator.This will bring various adverse effects to the performance of pitch angle controller,the most important of which is integral saturation.Integral saturation phenomenon will deteriorate the rotating speed regulation performance of the wind turbine when the wind speed fluctuates sharply.Therefore,it is needed to take the influence of integral saturation into account in order to improve the performance of pitch angle controller.Based on the consideration of actual operating limitations of the pitch actuator,this paper uses the compensation method of anti-windup algorithms to design an anti-windup pitch angle controller,which is suitable for wind turbine systems.The main research results are as follows:A.Analyze the mechanism of integral saturation phenomenon in wind turbine pitch angle control,and put forward an evaluation index of saturation degree.Firstly,describe the phenomenon of amplitude saturation and rate saturation in wind turbine pitch angle control,and point out the difference and connection between the two kinds of saturation.Secondly,based on the comparison of sensitivities,the mechanism of rate saturation is explored.Finally,an evaluation index of saturation degree is proposed,and the influence of different kinds of saturation on the performance of pitch angle control is analyzed.B.Based on the compensation method of anti-windup algorithms,an anti-windup pitch angle controller suitable for wind turbine system is designed.The compensation structure is improved by the design of equivalent inertia link,avoiding the adverse effects on the antiwindup pitch angle controller which is due to the inertia of pitch actuator.And the selection method of the compensation coefficient is proposed,which is based on adaptive algorithm.C.The effectiveness of the anti-windup pitch angle controller proposed in this paper is verified based on the software FAST and the wind turbine dynamics imitation experimental system.Both simulation and experimental results show that compared with other control algorithms,the improved method of this paper can show better performance in rotating speed regulation.更多还原