Linear active disturbance rejection speed control with variable gain load torque sliding mode observer for IPMSMs

A Linear Active Disturbance Rejection Control (LADRC) method with a Variable Gain Load Torque Sliding Mode Observer (VLTSMO) is proposed in this paper to reduce the effects of the load torque disturbance of Interior Permanent-Magnet Synchronous Motors (IPMSMs). First, the LADRC is used as a speed loop controller, and the linear extended state observer (LESO) is used to observe the total disturbance. Then the stability of the controller is analyzed. Second, the VLTSMO is proposed, which can output a feedforward compensation signal to improve the observation capability of the observer. In addition, after comparing several standard switching functions, the continuous switching function is selected to reduce the chattering phenomenon. Finally, a 5.5 kW IPMSM is taken as the research object. A simulation model and the dSPACE motor control platform are used to realize the algorithm. Both simulation and experimental results show that the VLTSMO has excellent observation capabilities. They also show that the LADRC + VLTSMO method can effectively improve the dynamic performance and robustness of the speed control system.