【作者】 王洋；

【导师】 郭鹏；

【作者基本信息】 华北电力大学(北京) ， 检测技术与自动化装置， 2016， 硕士

【摘要】 风能是一种清洁可再生能源,在全球关注的环境保护的背景下,世界各发达国家都着重开发利用无污染或少污染的可再生能源和新能源,这样既可以保护环境又可以节约能源。风力发电技术包括大型风力发电机组并网技术已基本成熟,因此风电场的装机容量也在逐渐增加。也正是因为风电机组容量的增加,风电场的稳定运行对电力系统的影响也在渐渐增大。当电网发生故障时,也就要求风机能够继续并网运行,因此研究双馈风机低电压穿越能力具有重要意义。本文主要工作内容如下：1、对双馈风力发电机的基本结构进行了研究,并对其原理进行了简单介绍,分析了双馈风力发电机在三相静止ABC坐标系下的数学模型和在两相旋转dq坐标系下的数学模型,为研究双馈风机低电压穿越技术提供了理论指导。2、在双馈风力发电机数学模型的基础上,详细分析了故障期间双馈风力发电机的暂态过程,对故障期间双馈风力发电机转子电流升高和直流母线过电压的机理进行了研究,并进行了仿真验证。3、在传统Crowbar保护电路的基础上,分析了Crowbar阻值对双馈风机低电压穿越能力的影响,确定了Crowbar保护电路阻值的最优取值区间。并提出一种新型电阻串电容Crowbar保护电路,与传统Crowbar电路相比,不仅能更好的抑制转子过电流,而且缩减了故障初期转子过电流的暂态过渡过程。最后,利用仿真软件MATLAB/SIMULINK搭建了双馈风力发电系统的仿真模型,验证了上述方法的正确性。更多还原

【Abstract】 Wind energy is a clean and renewable energy, under the global concern for environmental protection. The developed countries are focused on the development of the use of non-polluting or less polluting renewable energy and new energy, both to protect the environment and energy conservation. Wind power generation technologies, including large-scale wind turbine and grid-connected technology have been basically mature. The installed capacity of the wind farm is also increasing. Because of the increase in the capacity of the wind turbine, stable operation of the wind farm is more important to the power system. When the grid fault occurs, it also requires the wind turbines to be able to continue working. So, the study on low voltage ride-through capability of doubly-fed wind turbine is of great significance.1. This paper studies the structure and principle of double-fed wind power generation system, and analyzes the mathematical model in static three-phase ABC coordinate system of the doubly-fed wind power generator and in two-phase rotating dq coordinate system of the mathematical model, which provides theoretical guidance For the low voltage ride-through technology research of DFIG.2. According to the mathematical model of the generator, it analyzes the DFIG transient electromagnetic relation, and gives further analysis of the DFIG rotor overvoltage and overcurrent.3. Then, based on the mathematical analysis, the method to choose the appropriate value of Crowbar resistor was introduced. Furthermore, a modified Crowbar protection circuit with resistance in series with a capacitor was proposed to shorten the transition process of the rotor over current. Finally, based on the platform of MATLAB/SIMULINK, a DFIG simulation model is built, which is used in various simulations in the studies.更多还原