低转速直驱式永磁同步风力发电机直接转矩控制性能优化

发布时间：2018-03-01 07:29

本文关键词： 风力发电直接转矩控制扩展卡尔曼滤波转速控制 SVPWM　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：在能源危机日益严重的今天,新能源开发和利用已迫在眉睫。风能作为一种绿色能源取之不尽用之不竭,是未来最有前景的新能源之一。风能的有效利用依靠风机的精确设计以及控制系统的开发。早期的风电系统主要为恒速恒频系统,其风机设计简单,控制系统相对简化,随着技术的进步特别是电力电子技术的飞速发展,风电系统逐渐演变为变速恒频系统,风机转速可以跟踪风速变化,使风能的利用达到最优。变速恒风电频系统的配置方式又有很多种,不同的发电机配备相应的电力电子变流装置可以组成种类繁多特点各异的风力发电系统。在风速较低的情况下,风电机组控制主要体现在转速控制上。本文针对风力发电机转速控制问题展开分析:首先介绍了本文的研究背景以及当前风力发电产业的发展状况,分析了几种常用的风力发电系统及其各自特点,对风力发电系统的控制系统进行了简要的介绍并重点分析了低于额定风速情况的风力发电机转速控制策略。其次介绍了风力发电系统的结构以及组成,对组成风力发电系统的重要部分做了详细的阐述并建立了其数学模型,其中推导了永磁同步发电机的数学模型,并在静止坐标系下对其模型进行了推导,之后通过坐标系变换对其数学模型进行化简,达到易于控制的目的。同时对低于额定风速下的风机最大功率跟踪控制策略也进行了进一步的说明。然后介绍了基本直接转矩控制的基本原理及其在永磁同步发电机上的具体应用,对其实现过程做了分析,通过仿真发现基本直接转矩控制存在转矩脉动较大、控制不精确等问题。为解决这些问题采用空间电压矢量调制(SVPWM)的方法对直接转矩控制进行优化,结果表明转矩脉动问题得到了明显改善,同时保持了较好的动态性能,最后针对系统运行过程中参数变化的问题设计了基于扩展卡尔曼滤波器的定子磁链观测器,使得系统具备更好的抗干扰能力和鲁棒性。最后结果显示优化系统能够跟踪快速变化的风速并保持良好的控制性能。
[Abstract]:With the increasingly serious energy crisis, the development and utilization of new energy is imminent. Wind energy, as a kind of green energy, is inexhaustible. Wind energy is one of the most promising new energy sources in the future. The effective use of wind energy depends on the precise design of wind turbines and the development of control systems. The early wind power systems were mainly constant speed and constant frequency systems, with simple fan design and relatively simple control systems. With the progress of technology, especially the rapid development of power electronics technology, wind power system gradually evolved into variable speed constant frequency system, fan speed can track the change of wind speed. The use of wind energy is optimized. There are many ways to configure the frequency system of variable speed constant wind power. Different generators equipped with corresponding power electronic converters can form a wide variety of wind power generation systems with different characteristics. Wind turbine control is mainly reflected in speed control. This paper analyzes the speed control of wind turbine. Firstly, the research background of this paper and the current development of wind power generation industry are introduced. Several commonly used wind power systems and their respective characteristics are analyzed. The control system of wind power system is introduced briefly, and the speed control strategy of wind turbine under rated wind speed is analyzed emphatically. Secondly, the structure and composition of wind power system are introduced. The important part of wind power generation system is described in detail and its mathematical model is established, in which the mathematical model of permanent magnet synchronous generator is derived, and its model is deduced in static coordinate system. Then the mathematical model is simplified by the transformation of coordinate system. At the same time, the maximum power tracking control strategy of fan under rated wind speed is further explained. Then the basic principle of direct torque control and its application in permanent magnet synchronous generation are introduced. The concrete application of motor, The realization process of DTC is analyzed, and it is found by simulation that there are some problems such as large torque ripple and inaccurate control. In order to solve these problems, space voltage vector modulation (SVPWM) method is used to optimize DTC. The results show that the torque ripple problem is obviously improved while maintaining better dynamic performance. Finally, a stator flux observer based on extended Kalman filter is designed to solve the problem of parameter change during the system operation. Finally, the results show that the optimized system can track the rapidly changing wind speed and maintain good control performance.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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