基于反电动势滑模观测器的异步电机矢量控制

为提高异步电机无速度传感器控制参数鲁棒性,同时减小滑模抖振,研究了一种基于反电动势高阶滑模观测器的异步电机速度观测和矢量定向方案。在对异步电机数学模型变换的基础上,通过非奇异终端滑模观测器的设计,实现了对反电动势的准确观测。据此设计了转速适应率,实现了转速观测,并由反电动势和转子磁链之间的故有相位关系,实现了转子磁场的直接定向。该方案的突出优势在于其较强的参数鲁棒性:一方面,其矢量定向的准确性不受转子电阻这一易变参数的影响;另一方面,转子电阻的变化对速度观测精确度的影响较小。同时高阶滑模观测器的设计有效地抑制了滑模抖振,提高了观测精确度。仿真结果验证了该方案的有效性,展示了其较强的参数鲁棒性。

Back-EMF based sliding mode observer for vector control of induction machine

To improve robustness of speed sensorless control of induction motor and reduce sliding mode control chattering, a high-order sliding mode observer for back electromotive force ( EMF) in induction machine ( IM) is investigated to achieve the speed estimation and the vector orientation.By operating the mathematical model of IM, and designing on a non-singular terminal sliding mode observer, the EMF was observed accurately.Further, the speed adaptation law and speed observation scheme were figured out, meanwhile, based on the phase property of the observed EMF out of the rotor flux, the direct orientation of vector control was obtained with the designed observer.One of the advantages of the strategy is with high parameter robustness.Namely,the accuracy of the vector orientation is not affected by the parameter of rotor resistance,and the negative impact on speed accuracy is scarcely perceptible.In addition, the chattering disturbance resulting from the discontinuous control in sliding mode observer is inhibited well in the high-order sliding mode observer, improving the observation accuracy.The simulation results show the validity and robustness of the proposed strategy.