混合转子开绕组无刷双馈风力发电机的直接功率控制研究

发布时间：2018-03-17 08:31

本文选题：无刷双馈电机　切入点：开绕组　出处：《沈阳工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着化石能源供应日趋紧张,环境问题日益严重,风能作为一种清洁的可再生能源受到了国内外专家和学者的广泛关注,但目前风力发电技术中主要应用的双馈感应发电机和永磁同步发电机具有维护频繁,控制方法复杂,变频器容量较高、造价昂贵等诸多问题。无刷双馈发电机作为一种新型电机,成本低廉且不需要频繁维护。本文以无刷双馈发电机为研究对象,以国家自然科学基金项目“复合转子开绕组无刷双馈风力发电机及其直接功率控制策略”(项目批准号：51277124)为背景,提出一种适用于该电机的直接功率控制方法,并在以下方面进行重点研究：首先,概述了混合转子开绕组无刷双馈风力发电机特殊的定子开绕组结构和新型转子的磁场调制作用,论述了电机的工作机理和三种不同的运行方式,以及在不同运行方式下的功率流向问题。建立了适用于该种电机控制的旋转坐标系下的数学模型,并给出了电机的等效电路图。其次,根据混合转子开绕组无刷双馈风力发电机的特殊结构,将直接功率控制方法进行适当改进,应用到该电机上。直接功率控制方法功率响应速度快,不需要复杂的坐标变换,计算量小,且对电机的参数变化不敏感,解决了现有控制系统算法复杂等问题。分析发电机定子上两套绕组的电压关系,设计了稳定输出电压的方法,并进行了仿真验证,为电机的后续并网运行奠定基础。再次,分析了开绕组电机的空间电压矢量,并根据矢量幅值将其分为短、中、长矢量三种,并对三种不同幅值矢量分别进行直接功率控制方法的仿真,将三种方法的仿真结果对比,分析其优劣及适用情况。接着,对控制方法进行优化,提出了混合矢量法和基于功率误差比较的直接功率控制方法,分别在转速突变,功率给定突变,运行方式变化等情况下,使用MATLAB/Simulink软件对这两种优化方法进行仿真分析,仿真结果表明这两种方法虽然略微增加了控制方法的复杂度,但可以大大提高控制系统的控制精度,减小了功率绕组输出电流的畸变率。最后,以TMS320F28335DSP为控制核心,制作了两台四象限变频器,设计了信号调理、电压电流采样、IGBT驱动等电路,搭建了混合转子开绕组无刷双馈风力发电机的直接功率控制系统实验平台,并使用一台额定功率42kW的混合转子开绕组无刷双馈电机进行实验,验证了开绕组电机控制方法的可行性。
[Abstract]:With the increasingly tight supply of fossil energy and the increasingly serious environmental problems, wind energy as a clean renewable energy has been widely concerned by experts and scholars at home and abroad. However, the doubly-fed induction generator and permanent magnet synchronous generator, which are mainly used in wind power generation technology, have the advantages of frequent maintenance, complex control methods and high inverter capacity. As a new type of motor, the brushless doubly-fed generator is low cost and does not need frequent maintenance. In this paper, the brushless doubly-fed generator is taken as the research object. Based on the project of National Natural Science Foundation, "Brushless Doubly-fed Wind Generator with compound rotor Open Winding and its Direct Power Control Strategy" (Project Grant No.: 51277124), a direct power control method suitable for the motor is proposed. The following aspects are emphatically studied: firstly, the special stator open-winding structure of the hybrid rotor open-winding brushless doubly-fed wind turbine and the magnetic field modulation function of the new rotor are summarized. The working mechanism and three different operation modes of the motor and the power flow direction under different operation modes are discussed. The mathematical model under the rotating coordinate system suitable for the control of the motor is established. The equivalent circuit diagram of the motor is given. Secondly, according to the special structure of the hybrid rotor open winding brushless doubly-fed wind turbine, the direct power control method is improved appropriately. When applied to the motor, the direct power control method has the advantages of fast power response, no complicated coordinate transformation, less computation, and insensitivity to the parameter change of the motor. This paper analyzes the voltage relationship between two sets of windings of generator stator, designs the method of stabilizing output voltage, and carries out simulation verification, which lays a foundation for the subsequent grid-connected operation of the motor. The space voltage vector of open-winding motor is analyzed, and it is divided into three kinds according to the vector amplitude, which are short, medium and long vector. The direct power control methods of three different amplitude vectors are simulated, and the simulation results of the three methods are compared. Then, the hybrid vector method and the direct power control method based on power error comparison are proposed, respectively, in the case of rotational speed mutation, power given mutation, operation mode change and so on. The two optimization methods are simulated and analyzed by using MATLAB/Simulink software. The simulation results show that the two methods increase the complexity of the control method slightly, but can greatly improve the control accuracy of the control system. The output current distortion rate of power winding is reduced. Finally, two four-quadrant frequency converters are fabricated with TMS320F28335DSP as the control core, and signal conditioning, voltage and current sampling and IGBT-driven circuits are designed. An experimental platform of direct power control system for a hybrid rotor open-winding brushless doubly-fed wind turbine is built, and an experiment is carried out with a brushless doubly-fed machine with rated power of 42 kW. The feasibility of the open winding motor control method is verified.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM315

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