基于MRAS的双馈风力发电机无速度传感器直接转矩控制

DIRECT TORQUE CONTROL SYSTEM WITHOUT SPEED SENSOR OF DOUBLY FED GENERATOR BASED ON MRAS

针对速度传感器安装不方便、成本高,磁链观测对电阻依赖性强的问题,提出一种基于模型参考自适应策略的速度、电阻自适应转子磁链观测器,该观测器以转子电流和转子磁链为状态变量,应用李雅普诺夫稳定理论获得转速自适应律,实现转子转速和定子电阻辨识。建立了Matlab/Simulik环境下的双馈风力发电机无速度传感器直接转矩控制系统的仿真模型,仿真结果表明该方法可实现转子磁链的精确辨识,有效减少双馈发电机的定子电阻对系统特性的影响,提高了系统的稳定性和鲁棒性。

Due to the inconvenient and expensive of the speed sensor and the variation of doubly-fed generator （DFG） parameters with time in a direct torque control system, a speed, resistance and flux adaptive observer was designed based on model reference adaptive control theory. The rotor currents and rotor fluxes were used as state variables to construct full order adaptive observer of stator flux in a wide speed range. The adaptive law of speed could be obtained to identify rotor speed and the stator resistance by Lyapunov theory. The direct-torque control without speed sensor system of DFG was established under Matlab/simulink, the results show that this method can identify rotor flux accurately, not only reduce the influence of stator resistance＇ s variation on machines performance effectively, but also enhance the stability and robust performance of the system.