【作者】 刘军；

【导师】 何玉林；

【作者基本信息】 重庆大学 ， 机械工程， 2011， 博士

【摘要】 由于风能的随机性、间歇性及波动性大等特点,风力发电领域依然有很多问题需要进一步深入研究。控制系统作为风力发电机组能否安全可靠运行的神经中枢,对实现其风能最大捕获、减缓机组疲劳载荷,延长其使用寿命等方面起着举足轻重的作用。同时,也是影响我国风力发电机组国产化进程的重要因素之一。该论文依托重庆市重点科技攻关项目“风电机组系统设计关键技术”(项目编号:CSTC2007AB3052),对风力发电机组的整机建模、控制策略优化、控制算法设计及实验平台构建等进行了深入研究,论文的主要内容及结果如下:第一章阐述了世界风力发电的发展趋势,讨论了中国风电产业面临的机遇与风险,指出了目前风力发电机组控制系统的研究现状和存在的问题,给出了论文的主要内容和结构。第二章研究了面向控制系统设计的风力发电机组整机模型。依据仿真系统中的“模块化”设计思想,将风力发电机组划分为气动、机械、电气和桨距系统四个主要功能模块,并详细介绍了它们的工作原理和运行特性。特别针对桨距系统提出运用不同的变桨速率限制及动态尾流补偿机制消除其大转动惯量、滞后等不利因素的影响。第三章提出一种综合性能的优化控制策略。其主要设计思想:在接近名义工作点之前就开始小范围的调整桨距角,同时配合转矩闭环控制来增加系统在名义工作点的可控性及减缓过渡区功率波动和瞬时载荷突变的范围,以寻求在最大风能捕获和最小机械载荷之间找到一个合适的平衡点。第四章,为实现对综合性能优化控制策略的最佳跟踪,设计了三控制器平滑过渡方案。由于过渡区的时变、非线性、强耦合等特征,传统的控制算法难以满足系统的静、动态性能指标。基于模糊神经网络的控制方法,具有无需依赖控制对象精确数学模型和能防止时变、参数扰动等因素的特性,本文在模糊控制器的基础上,设计了利用单个神经元在线调整模糊控制查询表的算法。并以1.5MW变速变桨距风力发电机组为被控对象进行仿真,仿真结果验证了所提控制策略及控制算法对风力发电机组整机性能优化是一种有效可行的方法。第五章,为实现风力与风力机之间的柔性连接,依据风洞设计原理,以轴流式通风机为源动力,自制风道作为气动通道,搭建了开放式风洞,创造了更加逼近自然条件下风力机运行的实验环境。又基于硬件在环仿真技术设计方法,构建了风力发电机组实验平台。在此基础上,为实现对风力机最大功率的跟踪要求,设计了控制系统的硬、软件结构。通过仿真与实测数据的对比,结果表明:设计的控制系统能较好的实现对最大功率的跟踪,亦很好的说明搭建的实验平台具有良好可靠性和可行性。第六章对论文进行总结,并对以后的研究进行了展望。更多还原

【Abstract】 Since wind energy possess great randomness, intermittence and fluctuation, wind energy field still has various problems need to be solved. Control system, servers as the brain of wind turbine generator system (WTGS) for safe operation, plays a pivotal role in wind energy capture maximization, system fatigue load reduction, service life extension and etc. Meanwhile, it is one of the key factors for WTGS localization. The work of the dissertation is under the support of The Key Technology of Wind Turbine System Design, Chongqing Key Scientific and Technological Project (Project Number: CSTC2007AB3052). The dissertation conducted in-depth research of WTGS in overall modeling, control strategy optimization, control algorithm design, experimental platform setup and etc. The structural layout of the dissertation is summarized as follows:Chapter 1 described worldwide development tendency of wind power technology, discussed the opportunities and risks the wind industry in China has been facing, pointed out the research status and existent problems of WTGS control system, and delivered main content and structure of the dissertation.Chapter 2 investigated the entire model of WTGS facing control system design. Based on‘‘module’design concept, divided WTGS into aerodynamics, mechanics, electrics and pitch system four main functional modules, and introduced their working principles and operating characteristics in great detail. Specifically aiming pitch system, proposed applying different pitch rate limit and dynamic wake compensation mechanism to eliminate the influence of unfavorable factors, such as big inertia and delay.Chapter 3 forwarded a synthetic performance optimization control strategy. Its main design methodology is to adjust pitch angle in small range before approaching nominal operating point, meanwhile, coordinate with closed-loop torque control to enhance system controllability at nominal operating point and to reduce power fluctuation and transient load jump range, targeted to find balance between maximum wind energy capture and minimum mechanical load.Chapter 4 devised the three controller’s smooth transition scheme to fulfill optimum tracking of synthetic performance optimized control strategy. Due to the time-varying, nonlinearity and strong coupling features of the transition region, traditional control methods cannot meet system static and dynamic performance benchmark. The control method, which is based on fuzzy neural network, can be independent of target accurate mathematic model and prevent time-varying, parametric perturbation and other factors. On the basis of fussy controller, an algorithm which can online adjust fuzzy control request form by using single neuron is presented. Applying the algorithm to simulate a 1.5MW variable-speed variable-pitch WTGS validated suggested control strategy and control algorithm and shows it is a feasible method for WTGS overall performance optimization.Chapter 5, according to wind tunnel design principle, using axial flow fans as original power and self-made wind duct as tunnel, established open type wind tunnel. The wind tunnel is to realize flexible connection between wind and wind turbine and create more realistic wind turbine operation circumstances. Furthermore, a wind turbine experimental platform has been setup based on hardware-in-the-loop simulation technology design method. To satisfy the tracking requirement for maximum wind turbine power output, the hardware and software structure have been designed as well. Through comparison between simulation and experiment, the results revealed: Designed control system can effectively track the maximum power, and thereby the established experimental platform is reliable and feasible.Chapter 6 summarized the dissertation and prospected for the future research work.更多还原