改进变结构控制在风力发电机转速跟踪中的应用

摘要

In order to obtain the optimum power factor through maintaining the ratio of blade tip speed to wind speed, a new method for controller design of generator speed tracking is proposed basing on variable structure control theory and dynamics model of wind driven generator. Switching surface of variable structure controller is founded with the error of generator speed and its corresponding error derivative. Exponential approach law is adopted to derive control algorithm for rotation torque in the process of generator speed tracking. Chattering phenomenon is restrained due to adaptive neuron which is used for approach speed adjusting online. Simulation results show that speed tracking precision of wind driven generator is improved by modified variable structure controllers. The method proposed in this article is effective and feasible.%为使风轮叶尖速度与风速之比保持不变以获得最佳功率系数,依据变结构控制理论,在风力发电机动力学模型基础上提出一种新的发电机转速跟踪控制器设计方法.该方法以发电机转速的偏差及其导数建立变结构控制切换面,选取相应的指数趋近律,经推导得到发电机转速跟踪时电机转动扭矩的变结构控制律.针对抖振现象,利用自适应神经元对趋近率进行在线修正.仿真结果表明:改进变结构控制器提高了风力发电机转速跟踪控制的精度,该方法有效可行.