【作者】 孙建锋；

【导师】 周双喜；

【作者基本信息】 清华大学 ， 电气工程， 2004， 硕士

【摘要】 由于日趋严重的环境与资源问题以及风能利用的成本低廉和技术成熟等原因,风力发电成为电力系统中相对增长最快的新能源发电技术,发展风电成为改善电力系统经济运行极为重要的措施。近几年,风力发电机组单机容量和风电场建设规模都日益扩大,但风力的随机性和间歇性会对电力系统稳定运行产生一定的影响,因此对于含有风电场的电力系统,需要建立正确的数学模型并对该系统进行仿真分析。作为分析的基础,本文建立了风速、风电机组和风电场的数学模型。风电机组的数学模型主要包括风轮机模型、传动机构模型和异步发电机模型,仿真分析了风电机组对于风速四种分量的响应。风电场模型研究中,考虑到尾流效应和地理位置等因素,风电场中各台风机位置处的风速并不相同,因此研究了风能分布的Jensen模型和Lissaman模型,并以72机的风电场为例计算分析,结果表明了风能分布模型在大规模风电场模型分析中的重要性。由于大量异步发电机并列运行模型的仿真会极大的浪费仿真时间,因此,本文提出了风电场电气部分参数的等值模型,并以三机系统为例,用Simulink仿真工具箱验证其有效性。综合风能分布模型和电气等值算法,本文提出了风电场仿真分析的流程图。基于上述模型,本文对风电场—无穷大系统进行了简单的仿真分析,主要包括小干扰稳定分析,风电场的并网、负荷扰动以及联络线故障时的暂态分析。然后以达里风电场所在系统为例,在稳态分析和暂态分析的基础上计算风电场允许接入最大容量。最后,本文研究了双馈电机的数学模型,用电力系统静态分析和暂态仿真分析的方法比较双馈发电机和普通异步发电机的特性,研究表明双馈电机对提高风电场短路容量比和改善功率因数都有显著的作用。更多还原

【Abstract】 Because of pressure of environment protection and energy resources, wind energy is developing fastest among all kinds of renewable resources due to its low cost and technical maturity. Wind generation has been an important measure in improving economical operation of power system. In recent years, capacity of wind generators and the scale of wind farm are becoming larger and larger, but the randomicity and intermittence of wind will produce disturbance on power system. Mathematical model of wind generators and wind farm should be established.As the basis of the analysis, wind speed, wind generators and wind farm are modeled. Wind generator model includes wind turbine model, transferring structure model and asynchronous generator model. Response of wind generators to four kinds of wind speed is simulated and analyzed. In the course of wind farm modeling, wind distribution Jensen and Lissaman model is established by reason of factor of wind wake effect and geographic location, different wind speed of 72 wind turbines in a wind farm is calculated, the results show the important role of wind distribution model on large scale wind farm researching. Aggregation arithmetic of electrical parameters of wind farm is designed because simulation of a great deal of asynchronous generators operation could cost so much time. A three-wind –generator wind farm connected to infinite bus is simulated to validate the aggregation arithmetic model. Base on wind distribution and electrical aggregation, arithmetic and flow chart of wind farm simulation is established.A simple wind farm connected to infinite bus is simulated and analyzed, which includes small signal disturbance analysis, transient analysis when wind farm starts to be connected, load fluctuates and fault of line in power system is occurred. Then the system involving DaLi wind farm is introduced to calculate the maximum capacity of wind farm connected to grid by steady analysis and transient analysis.The model of doubly-fed induction generators is established and operation mechanism is analyzed. Characteristics of doubly-fed induction generators and <WP=5>normal asynchronous generators is compared by steady analysis and transient analysis. The results show that doubly-fed induction generators have remarkable role in enhancing wind farm short-circuit capacity ratio and improving power factor.更多还原