【作者】 林勇刚；

【导师】 李伟；

【作者基本信息】 浙江大学 ， 机械电子工程， 2005， 博士

【摘要】 在能源消耗日益增长濒临枯竭,环境污染日渐严重的今天,作为可再生绿色能源的风能成为世界各国普遍重视的能源,风力发电技术也成为各国学者竞相研究的热点。变桨距功率控制是当今大型风力机的关键技术之一,本文对风力机变桨距控制技术从仿真到试验、从理论到实践进行了较为全面的深入研究。 论文首先从变桨距风力机空气动力学进行研究,得出变桨距变速恒频控制的理论基础,并通过数学模型仿真,最终验证其理论的合理性;针对国内的加工水平和相关元器件,从快速性、节能、安全性三方面考虑,设计了电液比例变桨距执行机构,并依据设计搭建了变桨距风力机半物理仿真试验台,试验台中风力机变桨距机构、控制器都是真机,而风力机的其它部分都采用数学模型代替,整个半物理仿真试验台相当于一台变桨距风力机。在此试验台上对开机、低于额定风速、高于额定风速、暂停、正常关机、紧急停机等各项工况进行试验,最终结果均能满足变桨距控制要求;由于变桨距风力机具有很强的非线性,采用传统的PID控制效果并不十分理想,采用预测控制进行变桨距控制,通过支持向量回归实现变桨距风力机非线性系统的辨识,由于电液比例变桨距机构的差动回路设计和风力负载的单方向性,在桨叶顺桨、逆桨时预测模型是不同的,同时考虑到齿轮箱负载冲击破坏,在预测控制的同时增加了扭矩的有限约束,提出了基于支持向量机双模型切换有限约束的风力机变桨距预测控制算法,在变桨距风力机半物理仿真试验台上进行试验,最终结果表明通过该算法发电机输出功率和齿轮箱扭矩都比传统PID控制更加稳定。 此外电动机的独立桨叶控制也是变桨距控制的一种重要方法,本文详细设计了独立变桨距执行机构,并提出了基于桨叶受力加速度权系数分配的独立变桨距模糊控制和基于桨叶方位角权系数分配的独立变桨距模糊控制算法,通过模型仿真验证,该控制算法不仅稳定了发电机的输出功率,同时减小了桨叶拍打震动。更多还原

【Abstract】 Now with energy resources being consumed increasingly to be exhausted and environment empoison being serious gradually, wind power is paid great attention to by more and more countries as renewable resource and pollution-free energy resource. The technology also becomes research hotspot of many scholar.In the thesis, the variable-speed constant-frequency pitch-controlled theoretical basis is put forward by research of wind turbine aerodynamic characteristics and is proved rationally by model emulation. Based on the domestic element and process level, the electro-hydraulic proportional pitch-controlled actuator is designed according to the characteristics such as rapidity, energy conservation and security. The pitch-controlled wind turbine semi-physical simulation test-bed is formed, with the pitch-controlled actuator, load device and control being real and the other of the wind turbine being substituted by emulational models. The semi-physical simulation test-bed equals to the real pitch-control wind turbine. In the test-bed, the control performances are all satisfied the demands under the condition of starting up, lower the rate wind speed, above the rate wind speed, parking, normal stop, and emergency stop. Because of the great nonlinearity of wind turbine, the traditional PID control effect is not very perfect. The model predictive control is adapted for pitch control. Support vector regression algorithm is used for wind turbine nonlinear system identification to identify wind turbine nonlinear system. Because the differential circuit is used in the electro-hydraulic proportional pitch-controlled system, the model of feathering is different from that of backpaddling. Therefore the two models are switched in the predictive control course. Considering that torque impact has greatly effect on the life length of gearbox, the torque load limited constraint condition is added to predictive control. Then, when wind speed is up the rated speed, the generator power is kept more steadily around the rated and the pitch load fluctuation is greatly lower than that by adopting the traditional PID control.The individual pith control by electromotor is also another good power control method. The actuator is designed in the thesis. The control strategy is to combine fuzzy control with the weight number that is mainly decided by the acceleration and the blade azimuth angle. The simulation result indicates that when the wind speed is higher than the rated speed, the pitch load fluctuation is greatly reduced and the output power is kept around the rated speed.更多还原