【作者】 马舜；

【导师】 李伟；

【作者基本信息】 浙江大学 ， 机械电子工程， 2011， 博士

【摘要】 潮流能转换系统是一种利用流体动能发电的新型的可再生能源利用机电系统。本文在对潮流能转换系统的水动力学及能量传递过程中的相关控制问题进行较全面的综述后,采用了理论分析、数学建模、数字预测及仿真试验、基于真实样机系统的试验台试运行试验、厂房试验、及实际海洋环境下的海上验证试验等研究方法,重点针对水平轴式潮流能转换系统的能量捕获装置的设计方法及水动力学特性、各能量转换环节的能量转换效率、潮流能系统的最大功率跟踪及变速恒频控制、及适用于潮流能系统的新型变桨距装置及相应的功率控制等关键问题展开研究。论文的各章节内容如下：第一章,概述了潮流能的特点、分布、及开发意义；分类综述了潮流能转换系统的特点及国内外研究现状,总结了潮流能转换技术所面临的挑战；综述了潮流能系统的水动力学、最大功率跟踪控制、功率稳定输出控制等方面的研究进展；结合课题的研究意义及来源,提出了论文的主要研究内容。第二章,分析了水平轴潮流能系统的能量转换原理。利用一维动量定量及叶素理论分别从宏观的能量变化角度及微观的叶片受力角度分析了水平轴潮流能透平装置的能量捕获原理,而将两者相结合的叶素动量理论给出了水平轴透平各项载荷的计算方法；分别介绍了基于机械传动及液压传动方法的系统二次能量转换原理；最后分析了潮流能系统最大功率跟踪运行及功率稳定输出运行的控制原理。第三章,采用了基于叶素动量理论的变速运行最优叶片设计方法设计了水平轴潮流能捕获装置；考虑了必要的模型修正后建立了捕能装置的水动力学性能预测的数字模型,利用该模型预测了不同安装角下的性能；针对25 kW试验样机,设计了后续的机电能量转换系统,并开展了样机系统的仿真试验、试验台试运行试验、及海上试验,各项试验结果显示潮流能捕获装置的功率特性、机电系统的能量转换效率、及整机系统的工作运行情况总体上令人满意,验证了潮流能捕获装置及机电能量转换系统的设计方法是合理有效的,所建立的水动力学性能预测模型是正确有效实用的,以及检验了整套潮流能试验样机系统的可靠性及鲁棒性。第四章,首先对采用机械传动方式的潮流能系统的最大功率跟踪控制开展研究,提出基于负载调节方法的功率控制方案,建立了系统的数学模型,并开展了仿真对比试验及静态最大功率跟踪控制试验来验证所提出的调控方法及实现方案；然后对液压传动式潮流能转换系统开展了探索性研究,提出了基于泵马达蓄能器配置的液压式潮流能系统的实现方案,通过Simulink及Amesim的联合仿真初步验证了方案的可行性并对液压元件的作用进行了评估；最后对基于容积调节结合负载调节方法的液压式潮流能系统的变速恒频控制开展了研究,建立了液压式潮流能系统的数学模型,提出通过调节泵的排量来控制透平转速,调节负载大小来控制发电机转速,及调节马达排量来控制系统压力的变速恒频恒压复合控制的调控原理,开展了联合仿真试验,仿真结果及对比分析验证了调控原理的正确性,并对系统的控制策略进行了讨论。第五章,对液压式潮流能转换试验样机进行了设计及试验研究。依次设计了样机的液压传动系统、机械系统及电气控制系统,估算了系统的能量转换效率,并对样机系统开展了拖动试运行试验,获得了试验样机的各项性能指标,检验了系统的可靠性和稳定性,真实地验证了液压传动在潮流能转换系统中应用的可行性。第六章,对潮流能系统的变桨距装置及控制开展研究,设计并测试了一套新型的液压式变桨距控制系统。通过基于理论力学及叶素动量理论的桨叶受力分析,提出了潮流能系统变桨载荷的理论计算方法,根据水平轴潮流能系统变桨运动的特点,设计了由前置液压缸、齿轮齿条等组成的新型的潮流能变桨距执行机构及相应的电液比例控制系统,开展了变桨距系统的建模仿真及厂房试验,仿真及试验结果显示系统能够实现大范围的变桨对流,节距角的控制具有较理想的响应速度和控制精度。第七章,总结了论文的主要工作,阐述了研究结论和创新点,并对后续的研究工作进行了展望。更多还原

【Abstract】 Tidal current energy conversion systems (TCECS) are kind of innovative renewable energy systems which utilize the hydrokinetic energy for power generation. In this paper, the hydrodynamics of TCECS and some associated control issues in system’s energy transfer process have been reviewed firstly. Then through theoretical analysis, mathematical modeling, numerical prediction, simulation tests, and the real prototype system’s bench tests, workshop tests, and offshore validation tests, some key issues about TCECS have been studied, which include the design methods and the hydrodynamic performance of tidal current energy converters, the energy conversion efficiency of each part of TCECS, the maximum power tracking and variable-speed constant-frequency control of tidal system, the novel variable pitch device suitable for tidal current turbines and the associated power control, etc..The main contents of each chapter are as follows:In chapter 1, the features, distribution, and exploitation meanings of the tidal current energy are summarized firstly. Then the features and research status of the TCECS are reviewed by category, and the challenges of the tidal current energy conversion technologies are pointed out. The research development of the hydrodynamics, the maximum power tracking control, and the power stabilization control of the TCECS are summed up next. Finally, the supports, research significance, and main contents of this work are addressed.In chapter 2, the energy conversion principle of the horizontal axis TCECS are analyzed. First, based on the one-dimensional momentum theory and the blade element theory, the energy capture principle of horizontal axis tidal current turbines is analyzed from the point of view of energy change and the point of view of blade force. Then the calculation method of the load of the horizontal axis tidal current turbine is illustrated by the blade element momentum (BEM) theory introduced subsequently. In addition, the principle of the secondary energy conversion of the TCECS is presented from the aspects of the mechanical transmission and hydraulic transmission respectively. At the end, the control principles of the maximum power tracking operation and the power stabilization for TCECS are illuminated.In chapter 3, a horizontal axis tidal current energy converter is designed using the optimal blade design method for variable-speed operation based on BEM theory firstly. A hydrodynamic performance prediction numerical model including necessary modifications is then established, with which the turbine performance for various blade pitch angles is predicted. Subsequently, an electromechanical subsystem is designed and presented for a 25 kW TCECS prototype, and related numerical simulations, bench tests, and offshore tests are carried out in turn for the prototype. The results of these tests show that the power characteristic of the designed tidal current turbine, the energy conversion efficiency of the electromechanical subsystem, and the operation performance of the whole prototype system are basically satisfactory. This has illustrated that the design methods of the tidal current energy converter and the subsequent electromechanical subsystem are reasonable and valid, and the established hydrodynamic performance prediction model is correct and practical. Furthermore, the reliability and robustness of the whole tidal current energy conversion prototype are also validated.In chapter 4, the maximum power tracking control of the TCECS with mechanical transmission is studied firstly. A power control scheme based on the load regulation method is proposed. The system’s mathematical model is established. Following that, simulation comparison and static power tracking tests are carried out to validate the proposed regulation method and implementation scheme. At the second part of this chapter, some exploratory research on the TCECS with hydraulic transmission is carried out. A scheme for a hydraulic TCECS with hydraulic pump, motor, and accumulator is proposed and then validated preliminary through the co-simulation with Simulink and Amesim, and the effects of the main hydraulic components are assessed as well. At the third part of this chapter, the variable-speed constant-frequency control of the hydraulic TCECS is studied. The mathematical modeling and theoretical analysis are performed for the whole system, and a regulation and control principle for the variable speed, constant frequency and pressure operation of the system is proposed, which is based on the adjustment of the pump displacement, the load size, and the motor displacement. Co-simulation is also carried out for validation. The results with comparison analysis have validated the correctness of the proposed control principle, and some corresponding system control strategies are discussed as well at the end.In chapter 5, a hydraulic TCECS prototype is designed and tested. The design of the hydraulic drive subsystem, mechanical subsystem, and electrical control subsystem of the prototype are described in turn. The energy conversion efficiency of the system is estimated. Then a running-in tests is performed for the prototype in a motor driving test bed, through which the operation performance characteristic of the prototype is obtained and the system’s reliability and stability are checked. Thus, the feasibility of the application of the hydraulic transmission to the tidal current energy systems has been truly verified.In chapter 6, the variable pitch device suitable for TCECS and some related control issues are studied. Through the detail blade force analysis based on the theoretical mechanics and BEM theory, a pitching load calculation method is proposed firstly. Then according to the characteristics of the pitching motion of horizontal axis tidal current turbines, a novel variable pitch control system is designed, which consists of a pitching actuating mechanism with a fore hydraulic cylinder and a pinion-and-rack, and an associated electro-hydraulic proportional control subsystem. Subsequently, the mathematical modeling, simulation, and workshop tests of the pitch control system are performed. The Simulation and test results show that the designed pitching system has fast response and precise control of pitch angle, and also it is able to realize the bidirectional running of the TCECS with a large pitch adjustment range.In chapter 7, the major work of the study is summarized, and the conclusions and innovations are elaborated. Besides, the future work is also expected at the end.更多还原