直驱永磁同步风力发电机组低电压穿越技术的研究

发布时间：2017-12-31 05:01

本文关键词：直驱永磁同步风力发电机组低电压穿越技术的研究　出处：《东北电力大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着新能源的快速发展，风力发电机组的并网容量也在不断的增加，风力发电已然成为各国能源发展战略的重要方向。在风电比例较高的电网中，若风电系统在电网电压跌落期间大面积的脱网将会对电网造成严重的影响，所以应提高风机的低电压运行能力，使其在电网故障期间仍能保持并网运行，直到故障清除。本文主要针对提高直驱永磁风力发电机组的低电压运行能力展开相关的研究工作。首先，对全球风电发展的背景与现状进行了总结与阐述，并对国内外低电压穿越相关规定进行分析，指出了对直驱型风力发电机组低电压运行能力进行理论研究的必要性。其次，分析了直驱型风电机组的工作特性和运行原理，构建了基于dq同步旋转坐标系的永磁同步电机和全功率变流器的数学模型。在此基础上，分析了以发电机转速为控制量实现最大风能捕获的控制策略，，以及发电机转子磁链矢量定向控制策略和网侧变流器的电网电压矢量定向控制策略。然后，研究了当电网电压跌落时直驱永磁风力发电机组的运行特性。提出了一种新的低电压穿越协调控制策略，即将减少发电机出力、卸荷电阻控制和桨距角控制协调使用，以避免发电机超速和直流电容过电压为控制目标，保证变流器和发电机的运行安全，同时减少卸荷电阻的使用频率。最后，在仿真软件PSCAD/EMTDC中建立了具有低电压穿越控制电路的直驱永磁风力发电机组的仿真模型，设计电网电压轻度跌落和深度跌落两组算例，对电网发生三相短路故障时机组的低电压穿越能力进行仿真分析，仿真结果验证了本文提出的控制策略的有效性和正确性。
[Abstract]:With the rapid development of new energy, the grid-connected capacity of wind turbines is also increasing. Wind power generation has become an important direction of energy development strategy in countries. If the wind power system in the power grid voltage drop during the large-scale de-grid will have a serious impact on the grid, so we should improve the low voltage operation capacity of the fan, so that it can still maintain grid operation during the power grid failure. Until the fault clearing. This paper mainly focuses on improving the low voltage operation capacity of direct-drive permanent magnet wind turbine. First of all, the background and current situation of global wind power development are summarized and expounded, and the domestic and foreign low-voltage traversing related regulations are analyzed. The necessity of theoretical research on low voltage operation capacity of direct drive wind turbine is pointed out. Secondly, the working characteristics and operation principle of direct-drive wind turbine are analyzed, and the mathematical model of permanent magnet synchronous motor and full power converter based on DQ synchronous rotating coordinate system is constructed. The control strategy of maximum wind energy capture based on generator rotational speed is analyzed, as well as the vector oriented control strategy of rotor flux and the voltage vector oriented control strategy of grid-side converter. Then, the operation characteristics of direct-drive PMSG are studied when the grid voltage drops, and a new low-voltage traversing coordinated control strategy is proposed, which is to reduce generator output. The unloading resistance control and pitch angle control are used harmoniously to avoid overspeed of generator and overvoltage of DC capacitor to ensure the operation safety of converter and generator and to reduce the frequency of unloading resistance. Finally, the simulation model of direct-drive permanent magnet wind turbine with low voltage traversing control circuit is established in the simulation software PSCAD/EMTDC. Two sets of examples are designed to simulate the low voltage traversing ability of the unit when the three-phase short circuit fault occurs. Simulation results verify the validity and correctness of the proposed control strategy.
【学位授予单位】：东北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM315

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