Research on new direct torque control strategy of TLDMC-PMSM system

A new direct torque control method for three-level direct matrix converter permanent magnet synchronous motor (TLDMC-PMSM) based on the modulation coefficient optimization method (MCOM) is proposed to address the problems of large torque chain pulsation, amplitude disorder and weak system robustness in matrix converter permanent magnet synchronous motor system (MC-PMSM) using direct torque control (DTC). In the paper, firstly, the principle of MC-PMSM-DTC system is described; secondly, the two-level MC is replaced by TLDMC, the speed loop is cascade spiral sliding mode control, the torque magnetic chain loop is super twisting sliding mode control-direct torque control to replace the traditional PI control, and the modulation coefficient optimal method is introduced to reduce the drawback of gradually increasing motor torque fluctuation, and then the accurate control of PMSM is realized; finally, the feasibility and superiority of the proposed method are verified by MATLAB/Simulink simulation software and hardware experiments.