Sliding mode-based velocity and torque controllers for permanent magnet synchronous motor drives system

To minimise the torque ripple for vector control of interior permanent magnet synchronous motor (IPMSM) of railway traction system, this study proposes a new velocity, torque and current three-loop control system, and designs a velocity and torque sliding mode controller (SMC) for permanent magnet synchronous motor (PMSM) driven system. First, the mathematical model of IPMSM is described and the new velocity and torque closed-loop control system for PMSM is designed. Second, the velocity SMC and torque SMC are designed. The fast convergence of the motor velocity and torque is realised, and the torque ripple is reduced effectively. The stability of the designed SMC is analysed. Finally, the effectiveness of the proposed scheme was compared with PI by simulations and experiments. The results show that the proposed method has good control performance and strong robustness.