【作者】 卢剑涛；

【导师】 王耀南；

【作者基本信息】 湖南大学 ， 控制理论与控制工程， 2005， 硕士

【摘要】 在能源消耗日益增长、环境污染日渐严重的今天,在当今对可再生能源的开发利用中,风能由于其突出的优点而倍受关注,风力发电技术也成为各国学者竞相研究的热点。以交流励磁电机作为发电机运行的风力发电系统,利用变速恒频技术大大提高了风能的利用率。交流励磁发电机可改善电力系统稳定性,转子转速可变,具有独立的有功、无功功率调节能力。 本文对风力发电技术及变速恒频风电技术国内外研究现状作了比较全面的综述,介绍了交流励磁发电机的各种励磁控制策略和发展趋势。针对交流励磁发电系统对变频器的要求,设计了一种能量双向流动的双PWM变频器,满足了交流励磁发电系统励磁的需要,详细分析了三相电压型PWM整流器的基本原理和数学模型。通过仿真证明该系统能够很好的满足交流励磁发电系统的需要,具有低谐波、高功率因数、快速动态响应及能量双向流动等特点。通过对交流励磁发电机的三相静止坐标系数学模型和两相旋转坐标系数学模型的研究,提出了基于定子磁场定向的矢量控制策略。分析了交流励磁发电机的有功功率和无功功率调节过程。进行了包括并网、有功和无功功率独立调节在内的一系列仿真实验,仿真结果证明了模型和控制策略的正确性。 由于交流励磁发电机数学模型复杂,具有非线性、时变、强耦合等特点,受参数变化和外部扰动影响严重,使得传统PID控制效果受到制约。本文将模糊控制器引入其中,替换用于功率调节的传统PID控制器,通过仿真比较,结果表明模糊控制器具有更好的动态性能、收敛速度快、静差小,系统的抗干扰性有明显提高。更多还原

【Abstract】 Now, energy sources consume is increasing daily and environment pollution become more serious gradually. Because of its stand out merits, wind power is paid great attention in the exploitation of renewable energy source. The wind power generation technology has become the research hotspot of many country’s scholars. The wind power generation system with variable-speed constant-frequency (VSCF) can capture energy as much as possible. AC excited generator can improve the stability of electric power system, its rotor speed may adjustable and it has ability on adjusting alone of the active and reactive power.The research status of wind power generation technology and VSCF technology are summarized in this paper. All kinds of excitation control strategies for VSCF generator and future trends are reviewed. According to power relationship and the demand of AC excited generation system, it put forward and designed a dual PWM converter with the capacity of energy bi-directional flow. It also analyzed the basic theory and mathematical model of three-phase voltage source PWM rectifier. Simulation results show that the converter can satisfy the demand of AC excited generation system, such as low harmonic, high power factor, fast dynamic respond and energy bi-directional flow. After studying the mathematical model in static three-phase coordinate and in rotary two-phase coordinate, the stator field-oriented vector control strategy is issued. The process of active and reactive power regulating is analyzed. It did a series of experimental study including connecting to power network and the adjusting alone of the active power and reactive power. The results of simulation validated the validity and feasibility of model and control strategy.However, because the mathematical model of the AC excited generation system is complex, non-linear, time changing and coupling, and it is strongly affected by the varying parameter and exterior disturbing. The control performance of traditional PID controller is restricted. Thus, fuzzy control is introduced, and a stator field-oriented vector control system based on the fuzzy controller is presented in this paper. Compared with the simulation results of two systems, the fuzzy controller has better dynamic performance, smaller still difference, and it converges rapidly. The ability of robustness has been improved greatly.更多还原