【作者】 孙秋霞；

【导师】 李伟力；

【作者基本信息】 哈尔滨工业大学 ， 电机与电器， 2006， 硕士

【摘要】 随着人们对能源危机及环境污染的日益重视,风力发电在世界范围内得到了迅速发展,如何有效的提高机组容量与运行效率、最大限度地利用风能已成为风力发电技术研究的重要内容。在各种风力发电系统方案中,双馈感应风力发电系统以其独特的优点逐渐成为当今风力发电的主流。本文首先从双馈感应发电机的基本方程出发,建立其等效电路并研究功率平衡关系,结合一台实际样机,对其在变速恒频发电状态下的性能进行了分析,为双馈感应风力发电系统的研究奠定了理论基础。其次,介绍了风机的运行机理,对一台功率-转速曲线已知的风机进行数据读取建立风机的仿真模型,依据风机的运行特性,确定了采用功率控制来实现最大风能追踪的策略,建立了基于双PWM网侧变频器电网电压定向和转子侧定子磁链定向的矢量控制系统,通过调节转子励磁电流实现了变速恒频及并网后的功率解耦控制;在此基础上,对励磁系统加以改进,将电网电压及等效定子磁场电流的动态变化引入系统,在考虑电网波动情况下建立了风力发电励磁控制系统。然后,为防止发电机并网时刻对电网造成过电流冲击,满足柔性并网的要求,在总结现有并网技术的基础上,依据电磁场基本理论,建立了能够准确反映发电机电磁性能的有限元分析模型,计算出了空载运行时不同转速下发电机的特性曲线,为风力发电系统并网提供参考依据;此外,对不同转速、不同负载下的电机性能也进行了分析,并与所获得的实验数据相比较得出一些有益的结论。更多还原

【Abstract】 With attachment importance to energy source scarcity and environment pollution the wind electric power generation has developed dramatically all over the world. How to enhance unit capacity and operation effectively and use the wind energy becomes important matter of the wind electric power generation. In various system alternatives, variable speed constant frequency doubly-fed induction generator (DFIG) becomes mainstream for its advantages.First, based on DFIG fundamental equation, the dissertation creates equivalent circuit and internal power relationship, used a 3.5kw 6 poles wound induction generator as example, analyzes generator characteristic with different states, which establishes the theoretical foundation for succeeding study. The second, introduces wind turbine operation theory, according to the wind turbine characteristic, the maxim power capture scheme by the way of DFIG power control was put forward, power system voltage oriented vector control and stator flux oriented vector control is used respectively in the grid side and the rotor side converter, the variable speed constant frequency and decoupling the active and reactive power control are implemented by modulating the rotor current. On the base of traditional vector control, the improving excitation system is established by importing the dynamic change in network voltage and state flux current. The third, based on the analysis of existent techniques of wind generator grid-connection, According to the basic theoretical of electromagnetic, combining the FEM with external circuit, a mathematical model of the double fed induction generator is established in this dissertation, and generator no-load characteristic curve with different speed was calculated. Besides, the performance of double-fed wind generators at different speed and different load is calculated and compared with experimental data.Some benefit conclusion is gained.更多还原