【作者】 齐志远；

【导师】 王生铁；

【作者基本信息】 内蒙古工业大学 ， 动力机械及工程， 2009， 博士

【摘要】 风能是可再生能源中最重要的能源之一,风力发电对于改善能源结构、推动生态和环境建设具有十分重要的意义。小型风力发电系统具有投资小、使用灵活的特点,非常适合于解决居住相对分散、风力资源较好的无电地区居民的用电问题,具有广阔的市场前景。小型风力发电系统虽然已经在国内外大规模使用,但由于存在效率低和可靠性不高的问题,直接限制了小型风力发电系统的推广应用和发展。本文引入能量管理集成控制的思想,从分析系统工作原理、能量流动关系和工作模式转换入手,通过系统数学建模、仿真研究和实验研究,以期实现小型风力发电系统的优化及可靠运行。论文首先简述了风力发电的意义和风能利用及风力发电历史,综述了美国、加拿大、欧洲和我国的小型风力发电发展现状和趋势,总结了小型风力发电的应用状态及存在问题,概括了小型风力发电系统的国内外研究状况。其次,为了提高小型风力发电系统能量转换效率和可靠性,采用了定桨距风力机直接耦合永磁同步发电机的拓扑结构,在二极管整流桥与蓄电池之间插入DC/DC变换器实现功率调节,结合机械折尾翼与耗能电阻方式进行风力机限速保护。介绍了研究的小型风力发电系统各组成部分的工作原理,阐述了风力机运行特性、DC/DC变换器阻抗变换原理及通过DC/DC变换器实现最大功率跟踪控制和负载跟踪控制的功率调节原理。第三,分析了传统小型风力发电系统的工作特性,指出了系统无功率调节及风力机与发电机功率匹配不尽合理是系统效率低的主要原因,系统不对充放电电流进行控制会引起蓄电池提前损坏。为了实现系统的优化及可靠运行,将能量管理集成控制思想引入小型风力发电系统,完成对系统内部能量变换、流动及设备安全保护的检测和控制。分析了小型风力发电系统中的能量流动关系以及系统可能的工作模式,找出能量在系统内部转换的规律和工作模式转换条件,建立了工作模式转换图。第四,介绍了最大功率跟踪控制方法的原理,给出了一种无机械传感器的最佳功率给定法,针对小型风力发电系统的非线性和时变性特点,设计了一种自整定型模糊PID控制器进行功率调节。第五,分析了铅酸蓄电池的工作特性和影响蓄电池寿命的各种因素,结合快速充电原理和风力发电系统特性,提出了一种变电流快速充电和基于电流补偿的回差电压放电控制策略。变电流快速充电控制既能够快速储存能量,又可以避免过充电;具有电流补偿功能的回差电压放电控制能够保证在不同放电电流下蓄电池放出相同的能量,同时又避免过放电。第六,建立了小型风力发电系统的各组成部分的数学模型,针对能量管理集成控制的小型风力发电系统表现出连续子系统和离散子系统并存的混杂系统特性,给出了利用Stateflow仿真环境实现能量管理集成控制中工作模式间转换的逻辑控制。基于MATLAB平台建立了仿真电路,并对能量管理集成控制中的最大功率跟踪控制、负载跟踪控制和蓄电池充放电控制进行了仿真研究,仿真结果验证了小型风力发电系统能量管理集成控制方案的正确性和可行性。最后,设计并制作了一台具有能量管理集成控制功能的小型风力发电系统智能控制器,功率主电路选用Buck变换器进行功率调节,利用单片机C8051F410作为控制单元。在实验室环境下搭建了小型风力发电系统实验平台,利用该实验平台进行了智能控制器的性能测试。实验结果表明,控制器能够根据风速、负载和蓄电池状态自动切换工作模式,保持系统能量平衡,既可以充分利用风力发电机的输出功率,优先满足负载要求,又能够保证合理地对蓄电池进行充放电控制,进一步验证了能量管理集成控制方案的正确性及合理性,为该智能控制器的实用化提供了指导。更多还原

【Abstract】 Wind energy is one of the most important renewable energy, and wind power is very significant to improve energy structure as well to promote the development of ecology and environment worldwide. Because of the merits of small investment and flexible application, small wind power generation system is very suitable to solve electricity supply problem in those areas where the housing is relatively dispersed and wind resource is rich, and it has broad market prospects. Although a large number of small wind power generation systems have been used at home and abroad, its low efficiency and poor reliability have directly restricted the promotion and development of small wind power system. The idea of energy management integrated control is introduced to the small wind power system in this thesis, which is based on the analysis of its working principle, energy flow, working mode transition. Its mathematic modeling, simulation and experiment are carried out to achieve the optimal and reliable operation of small wind power system.Firstly, the significance of wind power and the history of wind energy application as well wind power are outlined. The present status and development trends of small wind power in United States, Canada, Europe and China are overviewed. The application state and existed problems are also summarized. In addition, the domestic and oversea research status of small wind power systems is summed up.Secondly, in order to improve reliability and upgrade energy conversion efficiency, the configuration of small wind power generation system in which fixed pitch wind turbine with folding tail vane directly drives permanent magnet synchronous generator is adopted. Furthermore, a DC/DC converter is inserted between generator and load to adjust power output of wind turbine, and mechanical folding tail vane together with dump resistance is used to protect wind turbine from overspeed. The operating principle of small wind power generation system and the characteristics of wind turbine are also introduced. In addition, the principle of impedance transformation of DC / DC converter and the ways to achieve maximum power tracking control and load tracking control by means of DC / DC converters are given.Thirdly, the characteristic analysis of conventional small wind power system shows that lack of power regulation and unreasonable match between wind turbine and generator are the main reasons of low efficiency, and the uncontrolled charge and discharge current leads to early battery damage. The idea of energy management integrated control is introduced to the small wind power system to achieve its optimal and reliable operation by its inner energy transformation, energy flow as well as component safety detection and control. Energy flow, working modes and transition condition of various working modes of small wind power system are analyzed, and the transition diagram of its various working modes is established.Fourthly, after the principle to obtain maximum power tracking control is introduced, a control strategy without both wind speed sensors and rotation speed sensors in which the rotation speed of generator is indirectly controlled according to optimum power set is put forward to achieve maximum power energy output at or below nominal wind speed. According to the non-linear and time-varying characteristics of small wind power generation system, a self-regulation fuzzy PID type controller is designed to implement power control.Fifthly, the characteristics of lead-acid battery are briefly summarized and various factors to impact on battery life are analyzed. Combined fast charging principles of battery with the characteristics of wind power generation system, a fast charge control method which applies different charge rate at different phase, and a discharge control strategy which use voltage backlash with current compensation are put forward. The fast charge control with variable current can make battery to swiftly store energy and avoid overcharge. The voltage backlash discharge control with current compensation can also ensure battery to release the same amount of energy at different discharge rate.Sixthly, the component mathematical model of small wind power generation system is established. Because small wind power system with energy management integrated control is a hybrid system with discrete and continuous subsystem, Stateflow is used to achieve the logic control of working state transition. MATLAB-based simulation model is established for small wind power generation system, and simulation results on its maximum power tracking control, load tracking control and battery charge and discharge control verify the correctness and feasibility of energy management integrated control of small wind power generation system.Finally, an intelligent controller with energy management integrated control for small wind power system is designed and implemented. A Buck converter is employed as main power circuit to achieve energy regulation, and single-chip microcomputer C8051F410 is used as control unit. An experimental platform for small wind power generation system is built up in laboratory to test the performance of intelligent controller. Experiment results show the controller can automatically switch between different working modes according to wind speed, load and battery status to maintain system energy balance. The small wind power generation system with energy management integrated control can make full use of the output power of wind turbine and ensure battery reasonable charge and discharge at the same time. The experimental results further confirm the correctness and rationality of energy management integrated control, and provide practical guidance for application of intelligent controller with energy management integrated control.更多还原