基于无速度传感器的无刷双馈风力发电机直接转矩控制

Direct Torque Control for Brushless Doubly-Fed Wind Power Generator Based on Speed Sensorless

根据风力机的功率输出特性,针对无刷双馈风力发电机,提出了一种基于直接转矩控制方法控制发电机转矩和功率因数来调节有功功率的最大功率跟踪方法。为了提高风电系统的可靠性,使系统更能适用于恶劣的风场环境,本文针对无刷双馈发电机复杂的内部磁场关系,设计了一种新型速度观测器,通过估算转子磁链同步旋转速度和转差速度来获得发电机转速。此外,还采用模型参考自适应辨识技术来设计控制绕组磁链观测器,以提高无刷双馈发电机在全速范围内磁链估计的准确性,进而改善直接转矩控制系统在控制绕组侧低频时的运行性能。仿真结果验证了所提出的新型转速估算方法的正确性和直接转矩控制方案的可行性。

A maximal power tracking method through controlling torque and power factor of brushless doubly-fed wind power generator to regulate active power is proposed based on direct torque control （DTC）, according to the power output characteristics of wind turbine. Considering the complicated relation of internal magnetic fields of brushless doubly-fed generator（BDFG）, a novel speed observer is designed by estimating the rotor flux synchronous rotating speed and slip speed to improve the reliability of wind power generation system in harsh wind field environment. Furthermore, the model reference adaptive identification technology is adopted to design control winding flux observer in order to enhance the accuracy of estimated flux within wide speed range and further to improve the operation performance of the DTC system at the low frequency of the control winding. Simulation results prove the validity and feasibility of the proposed novel speed estimation method and DTC scheme.