A Novel Sliding Mode Observer for Sensorless Control of Dual Three-phase PMSM

The sensorless control system of the dual three-phase permanent magnet synchronous motors (DTP-PMSM) based on the sliding mode observer (SMO) has the issues of low tracking accuracy and significant ripple. To solve this problem, this paper proposes an improved SMO(ISMO). Firstly, a mathematical of the DTP-PMSM is developed in a two-phase stationary reference frame. Based on existing reaching laws and switching functions, a novel rotor position observer is designed. Then, the stability of the observer is rigorously proven using Lyapunov's second method. Finally, simulations are conducted on the MATLAB/Simulink platform to validate the design. The comparative analyses with SMOs show that the improved observer significantly increases the response speed of the system and reduces chattering during the tracking process.