无刷双馈风力发电系统及其控制技术研究

论文总字数：46192字

摘 要

无刷双馈风力发电系统通过矢量控制等方法可实现变速恒频发电，特别适用于大功率场合下的风力发电，作为新型的风力发电系统，其结构、系统运行原理和控制策略与其他类型的风力发电系统都不相同，因此，研究无刷双馈风力发电系统的矢量控制技术、最大风能跟踪技术以及变速恒频控制技术，很有必要。

本文以无刷双馈风力发电系统为研究对象，首先介绍了级联式无刷双馈电机变速恒频发电的工作原理，研究了无刷双馈电机在不同坐标系下的动态数学模型，分析了无刷双馈电机的每相稳态等效电路以及功率流动，并搭建级联式无刷双馈电机的本体仿真模型，对其动态特性进行了研究。

然后介绍了通过单馈空载实验与单馈短路实验对级联式无刷双馈电机进行参数测量的方法，采用定子磁链定向矢量控制技术对级联式无刷双馈电机加以控制。阐述了风力机特性，研究了永磁同步电机的数学模型以及使用永磁同步电机模拟风力机的方法。针对无刷双馈风力发电系统探讨了几种最大功率点跟踪控制技术，包括最佳叶尖速比法、功率反馈法以及最优转矩控制，基于MATLAB/Simulink对无刷双馈风力发电系统进行了仿真研究。

最后在仿真成功的基础上搭建了基于dSPACE1103的无刷双馈风力发电系统实验平台，对定子磁链定向矢量控制技术以及最佳叶尖速比法、功率反馈法最大功率点跟踪控制技术进行了实验验证。仿真和实验结果表明：

1. 当采取定子磁链定向矢量控制技术时，可以实现发电状态下有功功率和无功功率的解耦控制，发出的电能频率、幅值稳定，满足电网要求，即实现变速恒频发电；
2. 最佳叶尖速比法最大功率点跟踪控制动态性好，能实现对转速的快速跟踪；
3. 功率反馈法最大功率点跟踪控制输出功率脉动小，可提高发电系统的稳定性；
4. 对于无刷双馈风力发电系统，最佳叶尖速比法控制需要实时测量风速，误差较大，且发电系统输出功率波动大，而功率反馈法控制无需测量风速，且发电系统稳定性高，因此选择功率反馈法用于最大风能跟踪。

关键词：变速恒频，风力发电，级联式无刷双馈电机，定子磁链定向矢量控制，最大功率点跟踪，Simulink

Abstract

The power converter of the brushless double-fed wind power generation system has small capacity, the system has no brushes and slip rings with high reliability, and can realize variable-speed constant-frequency (VSCF) power generation through vector control and other methods, and is particularly suitable for wind power generation in high-power applications. As a new type of wind power generation system, the brushless doubly-fed wind power generation system has different structure, system operation principle and control strategy from other types of wind power generation systems. Therefore, it’s necessary to study the vector control technology and maximum power point tracking (MPPT) control technology and VSCF control technology of the brushless double-fed wind power generation system.

Firstly, the basic structure of the cascaded brushless doubly-fed induction generator (CBDFIG) and the operating principle of VSCF power generation are introduced. The dynamic mathematical models of three-phase stationary coordinate system, two-phase arbitrary-speed rotating coordinate system and two-phase synchronous coordinate system are studied. The steady-state equivalent circuit of each phase and power flow of CBDFIG were analyzed. An ontology simulation model of CBDFIG was built, and its dynamic characteristics were studied.

Secondly the method of measuring the parameters of CBDFIG through the single-feedback no-load test and the single-feed short-circuit experiment is introduced. Taking it into account that the grid voltage remains unchanged, the stator flux-oriented vector control technology is adopted for CBDFIG. The characteristics of the wind turbine are described. The mathematical model of the permanent magnet synchronous motor and the method of using the permanent magnet synchronous motor to simulate the wind turbine are studied. Several MPPT control technology are proposed for brushless doubly-fed wind power generation systems. The MPPT control technology includes tip speed ratio (TSR) control, power signal feedback (PSF) control, and optimal torque (OT) control, simulation of brushless double-fed wind power generation system was studied based on MATLAB/Simulink, stator flux-oriented vector control technology and the MPPT control technology was verified one by one.

Finally, based on the successful simulation, an experimental platform for brushless doubly-fed wind power generation system based on dSPACE 1103 was built. Experimental verification was performed on the stator flux-oriented vector control technology, TSR control, PSF control. Simulation and experimental results show that:

(1) The stator flux-oriented vector control technology can achieve effective control of CBDFIG.

(2) The TSR control has the best dynamic performance and can track the reference speed quickly.

(3) The PSF control offers small output power ripple , andcan improve the stability of the power generation system.

(4) For the brushless doubly-fed wind power generation system, the TSR control method needs to measure wind speed continuously, the output power of the power generation system fluctuates greatly. The PSF control method needn’t to measure the wind speed, and the stability of the power generation system is high. Therefore, the PSF control method is selected for maximum wind energy tracking.

KEY WORDS: VSCF, CBDFIG, stator flux-oriented vector control, MPPT, TSR, PSF, OT, Simulink

目录

摘要 I

Abstract II

目录 IV

图录 VI

表录 VIII

第一章 绪论 1

§ 1.1 课题的背景和意义 1

§ 1.2 风力发电的发展状况 1

§ 1.3 风力发电系统 4

§ 1.3.1 风力机概述 4

§ 1.3.2 风力发电系统 4

§ 1.4 论文的研究内容 7

§ 1.5 论文的结构 7

第二章 级联式无刷双馈电机 8

§ 2.1 级联式无刷双馈电机变速恒频发电的原理 8

§ 2.2 级联式无刷双馈电机动态数学模型 9

§ 2.2.1 坐标变换 9

§ 2.2.2 三相静止坐标系 12

§ 2.2.3 两相任意速坐标系 13

§ 2.2.4 两相同步坐标系 15

§ 2.3 CBDFIG稳态等效电路及数学模型 16

§ 2.3.1 频率关系和转差定义 16

§ 2.3.2 稳态等效电路 17

§ 2.3.3 功率流动 18

§ 2.4 CBDFIG仿真模型 21

§ 2.4.1 CBDFIG本体仿真 21

§ 2.4.2 CBDFIG动态特性仿真 22

§ 2.5 本章小节 25

第三章 CBDFIG的参数测量和控制策略 26

§ 3.1 参数测量 26

§ 3.1.1 电阻的测量 26

§ 3.1.2 单馈空载实验 26

§ 3.1.3 单馈短路实验 26

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