电网故障下直驱式风力发电系统网侧变流器控制研究

发布时间：2018-10-20 12:04

【摘要】：风能以其独有的优势被广泛用于发电,以此来解决当今世界的能源危机。在各种风力发电技术中,直驱式风力发电技术是当前国内外研究的重点。直驱式风力发电机组接通过全功率变流器直接并入电网,通过变流器的控制实现电网与机组的解耦,相比于双馈型更能适应电网波动。但是直驱式风力发电机组在电网故障下运行时,依然会存在许多问题,这些都是直驱式风力发电技术研究的重点,尤其是电网发生不对称故障的情况下的问题是研究的难点。本文以直驱式风力发电系统网侧变流器作为研究的对象,针对电网故障情况对网侧变流器控制策略的展开研究工作。首先,介绍了风力发电技术的发展现状,对比了几种变频控制方案的,分析了直驱式风力发电系统在电网故障下的研究现状,提出了本文研究的主要内容。其次,针对电网故障情况下,网侧变流器的控制需要检测电网的电压电流信号,研究了电网故障下电网电压信号检测的方法。分析了传统基于同步旋转坐标变换锁相环检测方法的不足,在此基础上利用对称分量法对其进行改进,建立了基于双dq旋转变换锁相环检测模型,并进行软件仿真验证其正确性。再次,先对正常情况下网侧变流器的拓扑和控制策略进行分析,介绍了空间电压矢量脉宽调制(SVPWM)的工作原理和算法实现过程,并给出了软件仿真的模型。然后在此基础上,分析了电网不对称故障对直驱式风力发电系统的运行影响,针对电网不对称故障的情况,构建了网侧变流器的数学模型,提出负序电流前馈的控制策略,分析该策略的不足之处,引入了比例积分谐振控制器改善了负序电流前馈的控制策略的不足,利用Matlab软件仿真验证了所提出的网侧变流器控制策略的性能和效果。最后,在仿真的基础上,设计了实验的硬件电路,重点介绍了几个部分的详细设计过程。然后利用TI公司生产的TMS320F2812DSP芯片计了网侧变流器的数字控制程序,给出了主程序流程。
[Abstract]:Wind energy is widely used in power generation because of its unique advantages to solve the energy crisis in today's world. Among all kinds of wind power generation technologies, direct drive wind power generation technology is the focus of research at home and abroad. The direct-drive wind turbine is connected directly into the power network through full power converter and decoupled from the unit through the control of the converter, which is more adaptable to the fluctuation of the power network than the doubly-fed wind turbine. However, there are still many problems when direct-drive wind turbines run under power grid faults, which are the key points of research on direct-drive wind power generation technology, especially in the case of asymmetric power grid faults. In this paper, the grid-side converter of direct-drive wind power system is taken as the research object, and the control strategy of grid-side converter is studied according to the fault of power network. Firstly, this paper introduces the development of wind power generation technology, compares several frequency conversion control schemes, analyzes the research status of direct-drive wind power system under power network fault, and puts forward the main contents of this paper. Secondly, in view of the need to detect the voltage and current signals of the power network in the case of power network fault, the method of voltage signal detection is studied. The shortcomings of traditional phase-locked loop detection method based on synchronous rotation coordinate transformation are analyzed. On this basis, the symmetrical component method is used to improve the detection method, and the detection model of phase locked loop based on double dq rotation transformation is established. The correctness of the method is verified by software simulation. Thirdly, the topology and control strategy of grid-side converter under normal conditions are analyzed, and the principle and algorithm of space-voltage vector pulse-width modulation (SVPWM) are introduced, and the software simulation model is given. On the basis of this, the influence of asymmetric fault on the operation of direct-drive wind power generation system is analyzed. The mathematical model of grid-side converter is constructed, and the control strategy of negative sequence current feedforward is proposed. The shortcomings of the strategy are analyzed and the deficiency of the control strategy of negative sequence current feedforward is improved by introducing the proportional integral resonant controller. The performance and effect of the proposed control strategy are verified by Matlab software simulation. Finally, on the basis of simulation, the hardware circuit of the experiment is designed, and the detailed design process of several parts is introduced. Then the digital control program of the grid-side converter is calculated by using the TMS320F2812DSP chip produced by TI, and the main program flow is given.
【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】：TM46;TM614

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