Improved Model-Free Continuous Super-Twisting Non-Singular Fast Terminal Sliding Mode Control of IPMSM

To solve the problem of PI control cannot achieve satisfactory dynamic performance under complex operating conditions, an improved model-free continuous super-twisting non-singular fast terminal sliding mode control (NFTSM) algorithm (INFTSMC) for IPMSM based on improved extended higher-order sliding mode disturbance observer (IESMDO) is proposed. Firstly, the speed-current hyperlocal models of IPMSM are developed; Then, the speed-current controllers for INFTSMC are designed to optimize the current-speed dual closed-loops; where the jitter of system is effectively attenuated by combining third-order super-twisting with NFTSM; At the same time, IESMDO feeds back the disturbance of the speed and current loops to the controllers, it can effectively improve the performance for system control, and achieve fast-tracking of speed and d-q axis currents without overshoot; Finally, the algorithm is experimentally compared with PI and traditional NFTSMC to verify that the algorithm effectively improves the dynamic steady-state response and robustness of IPMSM.