Continuous Adaptive Fast Terminal Sliding Mode-Based Speed Regulation Control of PMSM Drive via Improved Super-Twisting Observer

A continuous adaptive fast terminal sliding mode based speed regulation control is proposed for a permanent magnet synchronous motor (PMSM) drive, where an improved super-twisting algorithm with linear terms (STLT) is constructed in the super-twisting speed observer. First, the STLT observer introduces a first-order term on the basis of conventional super-twisting sliding mode observer to improve the speed estimation convergence rate and to reduce the estimation error. Second, an adaptive function is added to the reaching law for the continuous fast terminal sliding mode speed controller to produce a faster response speed and stronger control robustness. In addition, the total disturbance of the system is estimated via Luenberger disturbance observer, which contributes to the feedforward compensation control component. The closed-loop stability analysis is rigorously given by the Lyapunov stability theory. Finally, real-time experiments on a PMSM platform are carried out to show the effectiveness and superior performance of the proposed control approach.