变速恒频风力发电机组最大能量捕获策略研究

风力发电主要目的是尽可能的利用风能,针对变速恒频风力发电系统,分析了风力机特性及最大风能捕获原理.在额定风速以下通过调节发电机的转矩使转速跟随风速变化以获得最佳叶尖速比;在额定风速以上通过调整桨叶节距,保证额定功率输出而不越限.由于风速测量的准确性不高,以及风力发电系统的精确模型较难建立,采用传统的PID控制器难以在风速快速变化的情况下实现良好的控制效果.为了进一步提高风能的利用效率,文中研究了基于功率变化信息的双模糊控制策略,实现最大功率点跟踪和变速变桨控制.仿真结果表明,该控制策略能够提高风能捕获效率,较好地平滑风电机组输出功率.

Study on Strategies of Maximum Energy Capture for Variable Speed Constant Frequency Wind Power Generation

The main purpose of the wind power generator is to use the energy as much as possible.For the variable speed-constant frequency wind power system,this paper analyzes the wind machine characteristics and the maximum wind power captured principle.Under the rated wind,by adjusting torque of the generator the control strategies make speed changes with wind speed,in order to get the best blade tip ratio.Over the rated wind,adjusting the blades pitch ensures that the output power does not exceed than the rated power.Because the wind speed measurement accuracy is not high,and the accurate model of the wind power system is hard to establish,and the good control effect in wind speed rapid change is difficult to realize using the traditional PID controller.In order to further improve the efficiency of the wind power,this paper studies the double fuzzy control strategies for the high power point tracking and the variable speed-variable pitch control based on the information of the power changes.The simulation results show that the control strategies can improve wind power captured efficiency,and the output power can be quite smooth.