双馈风电机组毕业设计论文.doc

摘要 本文是针对双馈风电机组低电压穿越的无功控制策略这一课题做的细致的研究，首先对风力发电的基本原理进行了介绍，分析了影响风力发电机组输出功率的几个因素，介绍了风力发电的发展趋势和国内外的风电发展概况，分析了不同结构的风力发电机组和不同的控制方法对风力发电机的控制，以及风电场对电网的影响和作用。因为在风力发电中，要把风速带来的能量最大化的转化为输入的机械功率，而不同的风速，控制发电机转子不同的转速可以实现最大的机械功率输入。 文中对双馈异步电机进行了数学模型的建立和仿真，通过详细的坐标变换的引入，将三相静止坐标系变换到两相同步旋转坐标系，我们选用最常用的基于定子电压定向的转子电流控制方式，实现双馈异步电机输出有功功率和无功功率的解耦控制，并且与定子磁链定向控制相比，不需要测量定子侧的磁链，所以实现起来较简单。并且当电网电压骤降时，通过对转子侧电流的控制，改变双馈异步电机输出的无功功率，对电网提供无功功率支持，改善电网的暂态稳定性。 关键词：双馈风电机组,无功控制,变速恒频,低电压穿越,定子电压定向 Abstract This article is for double-fed wind turbine low voltage reactive power control strategies across the subject do meticulous research,the purpose of the stator(grid)voltage directional control,so double-fed wind turbine to achieve the purpose of VSCF operation.While the double-fed wind turbine major failure occurs when the access to the grid(three-phase short circuit)on the low voltage ride through simulation analysis. First,the basic principles of wind power were introduced,analyzed several factors that affect the wind turbine output power,introduced the development trend of wind power and wind power development situation at home and abroad,and analyzes the different structures and different wind turbine control method for wind turbines,as well as the impact and role of wind farms on the grid.Because wind power,we should bring the wind to maximize energy into mechanical power input,and different wind speeds,different generator rotor speed control can achieve maximum mechanical power input,so the double-fed wind turbine control,mainly to control speed double-fed wind turbine,when the speed changes,it is necessary to control the rotor current,in order to achieve variable speed constant frequency operation. Paper,the doubly-fed induction motor to establish the mathematical model and simulation,through detailed introduction of the coordinate transformation,the three-phase stationary coordinate transformation to a two-phase synchronous rotating coordinate system,we choose the most commonly based on the orientation o