一种自适应滑模观测器的感应电动机转速辨识研究

Research on speed identification of induction motor of an adaptive sliding mode observer

在感应电动机无速度传感器矢量控制系统中,针对滑模观测器存在的转速抖振与辨识精度低的问题,设计了一种基于分段函数的自适应滑模观测器。首先,该观测器利用定子电流实际值与观测值的误差来构造滑模面,并使用了具有独立增益的分段函数作为电机观测模型的校正项,观测器的稳定性由李雅普诺夫理论(Lyapunov)证明。然后,以滑模趋近律作为改进手段,设计了新的转速自适应估计环节。仿真与实验验证表明,该滑模观测器增强了电机的暂态运行性能,能够很好地抑制转速抖振问题,电机全速范围内具有较高的磁链与转速观测精度,提升了电机调速系统的动稳态性能。

In the speed sensorless vector control system of induction motor, an adaptive sliding mode observer based on piecewise function is designed to solve the problems of speed chattering and low identification accuracy of sliding mode observer. First, the sliding mode surface of the observer is constructed by using the error between the actual value of the stator current and the estimated value, the piecewise function with independent gain is used as the correction term of the motor observation model, and the stability of the observer is proved by Lyapunov theory. Then, the sliding mode approach law is used as an improvement method to design a new speed adaptive estimation link. Simulation and experimental verification show that the sliding mode observer proposed not only enhances the transient operation performance of the motor but also suppresses the speed chattering problem well. The observer makes the motor have a higher magnetic flux and speed observation accuracy in the full speed range. The dynamic and steady performances of the motor speed regulation system have been improved.