Sensorless Control of DTP-PMSM Ship-Propulsion Drives by Using Nonsingular Fast Terminal Sliding Mode Observer

In this paper, a study of sensorless control of a dual three-phase permanent magnet synchronous machine (DTP-PMSM) for ship-propulsion applications is presented. A nonsingular terminal sliding mode observer is developed for fast and precise estimation of speed and position. The alpha-beta decomposition method is used to simplify the model of the DTP-PMSM by removing the interconnection between its windings. Based on this simplified model, a new terminal sliding mode observer is designed. The new observer introduces a sliding surface to alleviate the chattering problem in traditional sliding mode observers and ensure the convergence of the estimation error within a prescribed time. The proposed observer is applied to a 5-MW ship-propulsion DTP-PMSM in a MATLAB Simulink simulation. The simulation results confirm the superiority of it against the traditional sliding mode observer.