摘要变速恒频双馈风力发电系统具有变速运行范围宽，功率变换器容量小，系统运行效率高，成本低等优势。其中双馈异步电机采用双PWM变流器,其运行控制的核心就是其变流器的控制，所以本文主要研究双PWM变流器的控制策略以及仿真。64484

本文首先介绍双PWM变流器在风力发电系统中的应用以及其特点，阐述其工作原理，然后在三相静止abc坐标系下建立数学模型，再通过坐标变换建立两相旋转dq坐标系下的数学模型。网侧PWM变流器由双闭环串级PI控制，外环为电压环，内环为电流环，实现单位功率因数输入并在矢量控制原理基础上构建网侧PWM变流器控制模型与框图。通过分析建立双馈异步电机数学模型，确立定子磁链定向矢量控制，外环为功率环，内环为电流环的机侧PWM变流器控制模型与框图。

最后，利用MATLAB/SIMULINK平台，分别仿真实现了网侧与机侧的PWM变流器，进行了正常运行与启动过程仿真。并在此基础上，搭建了双馈异步电机双PWM变流器仿真模型。仿真结果基本验证并证明所设计的变流器可满足理论要求，并具有良好的稳定性。

毕业论文关键词：双PWM 变流器 矢量控制

毕业设计说明书（论文）外文摘要

Title    Control Strategy for Power Converters of Wind Power  Generation System                                                

Abstract The Variable-Speed Constant-Frequency (VSCF) wind power generation system with Doubly-Fed Induction Generator (DFIG) has been widely applied in the area of the wind power system. It has advantages over variable working wind speeds, smaller rating of the excitation converter, high efficiency of wind power extraction, low cost and so on. The core of the doubly-fed induction generator running control is totally connected with the control of the dual-PWM converter. According to this, the main task of this paper forced on the research of dual-PWM control strategy and simulation.

First of all, this paper introduced the application of dual-PWM converter in wind power generation system, its characteristics and the working principle. The mathematical model was established under the three-phase static coordinate system. And then, according to the coordinate transformation theory, the model of the two-phase rotating coordinate system was set up. The grid-side PWM converter was controlled by double close-loop PI control mode which consists of the outer voltage loop and inner current loop to realize unit power factor input. The control model of the grid-side converter was established on the control block diagram according to the principle of vector control. Then, through analyzing the mathematics model of doubly-fed induction generator, the control model and block diagram of the generator-side PWM converter with the outer power loop and inner current loop based on the stator-flux-oriented vector control.

At the end, simulation study was carried out on the platform of MATLAB/SIMULINK, which obtained the simulation results of the normal operation and the boot process of the grid-side and the generator-side PWM converter. On the basis of them, the simulation model of dual-PWM converter   was established. Approximately, the results of simulation prove that the design of converters can achieve theoretical demands and good stability.

Keywords  dual-PWM,  converter,  vector control

1  绪论 1

1.1  论文的研究背景和意义 1

1.2  变速恒频风力发电技术介绍 3

1.3  双PWM变流器控制的研究现状