基于磁链与负载观测器的异步电机反步滑模控制

针对参数摄动及负载转矩未知且变化会影响异步电机速度控制的问题,设计了一种改进型指数趋近律的滑模转子磁链观测器,用于估算电机转子磁通值,同时将磁通观测值用于负载转矩的估计。引入磁链误差、转速误差,通过反步滑模控制算法,将转子磁通与负载转矩的观测值用于异步电机控制。在转子电阻摄动与负载转矩未知且变化的情况下,将该控制策略与自适应反步控制方法进行实验结果对比。实验结果表明,该控制策略的响应速度快且跟踪精度高,提高了异步电机速度控制系统的抗干扰性能。最后,提出一种转速软给定方法,实验表明该方法能有效抑制转速变化时刻定子电流与电磁转矩的急剧增加,进一步改善了电机系统的性能。

Backstepping Sliding Mode Control of Induction Motor Based on Flux Observer and Load Observer

Aiming at the problem that the speed control of induction motor is affected by the parameter perturbation and the unknown and changing of the load torque,a sliding mode rotor flux observer based on the improved exponential approach law was designed to estimate the rotor flux value of the motor,and the flux observation value was used to estimate the load torque.By introducing flux error and speed error,the observation values of rotor flux and load torque were applied to the control of induction motor by backstepping sliding mode control algorithm.In the case of rotor resistance perturbation and the unknown and changing of the load torque,the proposed control strategy was compared with the adaptive backstepping control method by experiment results.The experimental results show that the proposed control strategy has fast response speed and high tracking accuracy,which improves the anti-interference performance of the speed control system of induction motor.Finally,a soft speed setting method was proposed.The experiment shows that the proposed method can effectively restrain the sharp increase of stator current and electromagnetic torque when the speed changes,and further improve the performance of the motor system.