【作者】 汪令祥；

【导师】 张崇巍；

【作者基本信息】 合肥工业大学 ， 电力电子与电力传动， 2011， 博士

【摘要】 近年来,风力发电技术取得了显著的进步,并逐渐成为新能源应用技术中的一个重要分支。本文以安徽省“十五”科技攻关项目和国家“十一五”科技支撑项目为依托,对风力发电应用技术中的永磁同步直驱型全功率风机变流器及其控制技术进行研究。在永磁同步风力发电机的数学模型、永磁同步风力发电机模拟器、永磁同步风力发电机的控制策略及其控制性能、永磁同步风力发电机无速度传感器控制、永磁同步风力发电机参数辨识、永磁同步直驱系统实验室模拟、直驱系统用全功率风机变流器的控制时序及全功率风机变流器的网侧、机侧变流器的协调控制等方面进行了深入研究,并获得了一些具有创新意义的科研成果。本文主要研究内容及创新点可概括如下:1、针对直驱系统采用的永磁同步风力发电机的电气结构和论文研究关注的重点,建立了三相和六相永磁同步风力发电机的数学模型,并重点分析了各自的特点。根据理论分析的模型方程,利用Matlab/Simulink建立了永磁同步风力发电机的通用仿真模型,并采用具体电机参数,给出了相关的仿真结果,三种模型的建立为后续针对永磁同步风力发电机控制策略和无速度传感器控制方法的研究建立了理论和仿真平台。2、提出了一种兆瓦级永磁同步风力发电机模拟器:根据兆瓦级永磁同步风力发电机的数学模型,可获取不同转速状态下的发电机定子电压和定子电流方程,通过控制三相电压型PWM变流器来近似模拟发电机的这种定子输出电压和电流特性,可达到验证全功率风机变流器带载特性和带载能力的目的,文中详细给出了发电机模拟器的控制系统设计并仿真验证了所提方案的可行性。3、对永磁同步风力发电机的常规矢量控制策略进行了详细的研究:分析了在实际工程应用的永磁同步直驱系统中,单纯采用常规的永磁同步发电机矢量控制方法的不足,结合实际的兆瓦级永磁同步风力发电机参数,文中提出了一种永磁同步风力发电机的复合矢量控制策略。此策略的提出使得当直驱系统中的永磁同步发电机运行在不同的工况时,对其控制可实现不同矢量控制策略的切换运行,从而提高整个系统的运行稳定性和提高发电机的发电效率。4、对永磁同步风力发电机的无速度传感器控制方法进行了研究:针对直驱系统中永磁同步风力发电机的特定运行工况,提出了一种锁相环加模型参考自适应方法的无速度传感器控制方法,该方法实现简单,辨识准确。文中给出了该控制方法的子系统设计和详细的仿真分析。此方法的提出,实现了直驱系统需无速度传感器控制的关键技术要求。5、对兆瓦级永磁同步风力发电机的参数进行辨识:针对矢量控制和无速度传感器控制方法需要准确已知永磁同步风力发电机参数的要求,文中对典型的最小二乘参数辨识方法进行了理论分析和仿真研究,并指出此方法虽然能准确辨识参数,但计算量稍显复杂,不利于工程实际应用。针对其不足,提出了一种适宜于工程应用中的基于无速度传感器矢量控制方法的直接参数辨识方法,文中并给出了详细的理论分析及仿真结果。6、对永磁同步直驱系统的拖带系统实验室模拟方案进行了探讨:根据不同的设计要求和实验目的,构建了不同功率等级下的三种永磁同步风力发电机的模拟拖带方案并进行了详细的实验研究。以此三种模拟拖带系统为平台,文中分别构建了不同功率等级的全功率风机变流器,并以此为平台,实验验证了文中所提的复合矢量控制策略和无速度传感器的控制方法的可行性和正确性,从而为后续针对实际风场的试运行奠定实验基础。7、对兆瓦级永磁同步直驱系统用全功率风机变流器的协同控制策略及控制时序进行了研究:针对全功率风机变流器的硬件特性和实际风场需实现低电压穿越的控制要求,对全功率风机变流器的网侧、机侧及直流侧撬棒电路的协同控制方案进行了较为系统的理论和实践研究。为实现实际风场的试运行,设计实现了全功率风机变流器的控制时序,并进行了长达半年的实际风场试运行测试。更多还原

【Abstract】 In recent years, wind power generation technology has made remarkable progress, and becomes an important branch of new energy technology. Based on the Subjects of Supported Program of Anhui Province during the 10th Five-year Plan Period, and the Subjects of Supported Program of the Ministry of Science and Technology during the 11th Five-year Plan Period (No. 2006BAA01A20) , this paper makes a deep study on correlative key technologies of full power wind turbine converter used in MW level permanent magnet synchronous direct-drive wind power generation system, comprising the permanent magnet synchronous generator (PMSG) mathematical model, vector control strategy & its performance, speed sensorless control method, parameter identification of PMSG, generator simulator and experimental simulation of PMSG wind power generation system, and control sequence & coordinated control of direct-drive full power wind turbine converter. Within the above research scopes, some scientific achievements, which are of innovation significance at certain extent, have been achieved. The main research content included in this paper, can be listed as follows:1. In allusion to the electrical structure and other concerned emphases of PMSG used in the direct-drive system, mathematical model of three phases & six phases PMSG are established, while putting highly emphasis on the analysis of their respective characteristics. According to the model and equation built by theoretical analysis, the universal simulation model of PMSG is established by Matlab/Simulink, and corresponding simulation results are given by adopting the actual generator parameters. Three kinds of model mentioned above have built the theoretic and simulation platform for the further study directing towards the control strategy of PMSG.2. A MW level PMSG simulator is proposed: According to the mathematical model of MW level PMSG, the stator voltage & current characteristics of generator under diverse rotate speed, can be acquired, then three phase frequency converter is adopted to approximately simulate the stator voltage & current characteristics, which aiming at validating the characteristic/feature and capability/ability of the load-bearing. In this paper, control system design of the PMSG simulator is described in detail, and the simulation results testify its feasibility.3. The common vector control strategy of PMSG is studied in details, and its shortages in the actual engineering application of direct-drive PMSG system, are analyzed as well. In accordance with the actual parameters of the MW level PMSG, a compound vector control strategy is proposed in this paper. This method has realized the switching control of different vector control strategies while PMSG in the direct-drive system is running in diverse operating condition. Thus improving the system stability and power generation efficiency.4. Speed sensor-less control strategy of PMSG is investigated: In allusion to the given operating condition of PMSG in the direct-drive system, a speed sensor-less control method which combines phase-locked loop (PLL) and model reference self-adaptation, is proposed. It is simple to implement, while its identification is exact, and its implementation h as fulfilled the technical requirements of sensor-less control in the direct-drive system. Subsystem design of this method and corresponding simulation analysis are also given in this paper.5. Parameter identification of MW level PMSG is researched: It is necessary for vector control and speed sensor-less control methods to acquire the accurate PMSG parameters. In allusion to above requirement, this paper illustrates the typical parameter identification method of least squares, and then the analysis and simulation results point out that this method can achieve the exact parameter identification, but it is not suitable for engineering application. For this reason, a parameter identification method based on the speed sensor-less vector control, which has good practicability, is proposed in this paper, and theoretical analysis and simulation verification show the better performance in detail.6. Experimental simulation scheme of direct-drive system is investigated: three kinds of simulated traction scheme of PMSG under diverse power level are constructed, and corresponding experimental investigations are also carried out. For different experimental purpose, based on the above simulated traction systems,the feasibility and validity of the compound vector and speed sensor-less control strategies, proposed in this paper, are testified by the experimental results, thereby establishing the foundation for the further trial running of direct-drive system in wind farm. 7. Coordinated control strategy & control sequence of MW level direct-drive full power wind turbine converter are studied in this paper: In allusion to the hardware characteristic of full power converter and low voltage ride through (LVRT) capability which is essential in wind farm, coordinated control scheme among the net side, motor side and crowbar circuit in the DC side of full power wind turbine converter is investigated. In order to guarantee the trial running of full power converter, its control sequence is designed and achieved, it undergo half year’s trial running experiment in the wind farm.更多还原