并网型电励磁同步电机风力发电系统研究

发布时间：2018-08-04 10:41

【摘要】：在当前全球资源日益枯竭和环境日益恶化的大形势下,开发和利用新能源已成为可持续发展战略的重要组成部分。风能作为无污染、极丰富的一种新能源,研究将风能转换成电能已成为国内外热点之一。相比于其他新能源的开发和利用技术,风力发电技术已有极大进展且发展迅速,但其主要核心技术被国外风电强国所垄断,所以研究风力发电技术非常有必要。本文首先着眼于风力发电系统整体,从综述的角度详细阐述了风能开发利用的必要性、国内外风力发电发展的现状和趋势,详细总结了目前国内外风力发电系统的拓扑结构和系统整体结构的种类及其优缺点,接着对风电系统中常用的三种控制策略作了详细说明。建立了风力机模拟系统,详细分析了风力机的工作原理,针对其数学模型以及功率特性曲线,为了获得与风力机相同的功率特性曲线,在经典直流电动机转速电流双闭环基础上添加功率外环,以此实现风力机的模拟系统。针对变速恒频风电系统的特点,为了提高风能捕获率,结合发电机直接转矩控制策略,采用最优功率／转矩法实现最大功率跟踪控制。对风力发电系统机侧和网侧控制策略进行了分析和研究。分析了直接转矩控制对电励磁同步发电机的控制原理,指出在转速一定情况下,快速控制电磁转矩即可快速控制功率的输出。分析了电网侧电压定向矢量控制策略的原理以达到并入大电网控制的效果。并对所分析控制策略进行了仿真和实验。针对电励磁同步电机功率因数可调的优点,为了充分利用变换器的容量、节约成本、减小转子绕组损耗,分析了直接转矩控制中转子励磁电流控制方法,实现定子侧单位功率因数控制。同时考虑到电机运行过程中电机参数变化的影响,加入了定子磁链矢量和定子电流矢量始终垂直的积分补偿,以期望达到真正的单位功率因数控制。对于直驱式电励磁同步电机风力发电系统,转速较低,而利用电压模型观测定子磁链不准确。为了实现风力发电全速度范围内的直接转矩控制,提出了一种基于转子高频电流注入观测准确转子位置角的方法,采用观测的位置角实现电流模型观测定子磁链,达到无位置传感器风力发电控制。仿真和实验证明本文所提无位置传感器并网型电励磁同步电机风力发电系统能在低转速以及零转速下稳定发电。为了验证本文提出的控制策略,设计了一套并网型电励磁同步电机风力发电全数字系统,以TMS320F2812 DSP作为控制芯片,以IGBT作为功率开关管,实验结果验证了该系统运行快速且可靠。
[Abstract]:At present, the development and utilization of new energy has become an important part of the strategy of sustainable development. Wind energy, as a new and abundant energy source, has become one of the hotspots at home and abroad. Compared with other new energy development and utilization technology, wind power generation technology has made great progress and developed rapidly, but its main core technology is monopolized by foreign wind power countries, so it is very necessary to study wind power generation technology. In this paper, the necessity of wind energy development and utilization, the current situation and trend of wind power generation at home and abroad are described in detail from the viewpoint of summarizing the wind power system as a whole. In this paper, the types and advantages and disadvantages of the topology and the overall structure of wind power system at home and abroad are summarized in detail, and then three control strategies commonly used in wind power system are explained in detail. The wind turbine simulation system is established, and the working principle of the wind turbine is analyzed in detail. According to its mathematical model and power characteristic curve, in order to obtain the same power characteristic curve as the wind turbine, The simulation system of wind turbine is realized by adding power outer loop on the basis of double closed loop of speed and current of classical DC motor. According to the characteristics of variable speed constant frequency wind power system, in order to improve the wind energy capture rate, combined with the direct torque control strategy of generator, the optimal power / torque method is adopted to realize the maximum power tracking control. This paper analyzes and studies the control strategy of wind power system. The principle of direct torque control (DTC) for electrically excited synchronous generator is analyzed. It is pointed out that the output of power can be quickly controlled by fast control of electromagnetic torque under certain rotational speed. The principle of voltage-oriented vector control strategy on power network side is analyzed in order to achieve the effect of integration with large power grid control. The control strategy is simulated and tested. Aiming at the advantages of adjustable power factor of electrically excited synchronous motor, in order to make full use of the capacity of converter, save cost and reduce the loss of rotor winding, this paper analyzes the control method of rotor excitation current in direct torque control. The stator side unit power factor control is realized. At the same time, considering the influence of motor parameters during motor operation, the integral compensation of stator flux vector and stator current vector is added in order to achieve real unit power factor control. For direct-drive synchronous motor wind power system, the speed is low, but the stator flux is not accurate by using voltage model. In order to realize direct torque control (DTC) in the full speed range of wind power generation, a method based on high frequency current injection of rotor to observe accurate rotor position angle is proposed. The current model is used to observe stator flux. Achieve position sensorless wind power generation control. Simulation and experiments show that the proposed sensorless grid-connected synchronous motor wind power generation system can generate power stably at low speed and zero speed. In order to verify the control strategy proposed in this paper, a fully digital wind power generation system of grid-connected synchronous motor is designed. The TMS320F2812 DSP is used as the control chip and IGBT as the power switch. The experimental results show that the system is fast and reliable.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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