Super Twisting-Based Position Control of PMLSM with Load Force Observer

High-precise and high-dynamic control is the most important requirement of permanent magnet linear synchronous motor (PMLSM) system. The main problem is to suppress the disturbances existing in PMLSM system. Sliding mode control (SMC) is one of the most robust control algorithms now, it can achieve high response speed and high robustness at the same time. But chattering problem is the main weakness of SMC. To solve that, higher order SMC algorithms have been developed. Super-twisting sliding mode control (STSMC) is a kind of second-order sliding mode control algorithm and has attract wide attention now. This paper presents a position controller for PMLSM based on STSMC, and demonstrates the advantages of this controller by comparing it with normal SMC controllers. Then a disturbance observer based on STSMC is presented, and with the observation result, the disturbance can be compensated, and the robustness of system can be further improved.