The robust deadbeat current predictive control (DPCC) is typically integrated with an extended state observer (ESO) to cope with uncertainties and disturbances of PMSM system, but usually fail to filter current harmonics caused by periodic disturbances, such as inverters nonlinearities. Furthermore, conventional DPCC primarily relies on forward difference discretization, which confronts stability challenges in the presence of parameter mismatches. Aiming at the above problem, a backward difference model free deadbeat predictive current control (BFDPC) strategy integrated with an improved extended sliding mode observer (IESMO) is proposed to simultaneously compensate for harmonic disturbances and lumped disturbance of PMSM system. Firstly, conventional DPCC method with sliding mode ESO is analyzed and the ESO amplitude characteristics with bandwidth is found. Secondly, an IESMO is proposed to simultaneously suppress the lumped and harmonic disturbances. Thirdly, a BFDPC method based on backward difference model by utilizing the Newtown-Raphson technique is designed to enhance the stability to parameter mismatches in DPCC. Finally, comparative experiments of DPCC, ESO-DPCC, and BFDPC strategies are implemented on a 64W PMSM experimental platform, and experimental results indicate that current harmonics under the proposed strategy can be effectively suppressed at both dynamic and steady conditions.

Predictive Current Control,PMSM,Sliding mode observer,Harmonic disturbance