风机基本工作原理和电能变换系统

Basic Operation Principles and Electrical Conversion Systems of Wind Turbine

综述了风机电能变换系统。首先论述了实现风机能量变换的基础,考虑了电气系统的需求。然后描述了3种变换系统(恒速、变速双馈式异步发电机和变速直驱式发电机)的优点和缺点。其次简单叙述了所应用的电力电子变换器。最后,讨论了可选择的发电机系统和其发展趋势。发展趋势很明显倾向于变速系统。越来越多的双馈式异步发电机系统安装了应对电网故障的装置。对于直驱式风机,径向永磁同步发电机比电励磁同步发电机更便宜且效率更高。发电机的电压等级可期望提高到约5kV。

This paper gives an overview of electrical conversion systems for wind turbines.First, the basics of wind energy conversion with wind turbines are reviewed and requirements with respect to the electric system are considered. Next, the three classical conversion systems are described with their strengths and weaknesses：constant speed, variable speed with doubly-fed induction generator and variable speed with direct -drive generator.The applied power electronic convertersare shortly addressed. Finally, alternative generator systems and trends are discussed. There is a clear trend towards variable speed systems. Doubly-fed induction generator systems are increasingly equipped with grid fault ride through capabilities. For direct-drive turbines, the radial flux permanent-magnet synchronous generator is cheaper and more efficient than the electrically excited synchronous generator. It is expected that the voltage level of generators will increase up to values in the order of 5 kV.