Research On Model Predictive Direct Torque Control Of Dual-three-phase Permanent Magnet Synchronous Motor

Dual-three-phase permanent magnet synchronous motors(PMSM)have excellent prospects in many industrial fields because it can increases output power only by using low-voltage power devices,performs well in high-power working environments,has smaller torque ripple and allows fault-tolerant operation with high reliability.In this paper,the vector decoupling mathematical model of dual-three-phase surface mounted permanent magnet synchronous motor is constructed,and its direct torque control strategy is deeply studied,which combines the direct torque strategy of SVPWM and the model predicted direct torque control strategy.The feasibility of the above control strategy are also studied on the experimental platform of MATLAB/Simulink and dual-three-phase permanent magnet synchronous motor.Firstly,the mathematical model of dual-three-phase permanent magnet synchronous motor in natural coordinate system is constructed,and the vect or decoupling method is used to deduce its mathematical model in rotor rotating coordinate system.The different voltage vectors produced by six-phase full-bridge inverter in dual-three-phase motor are classified.On this basis,the direct torque control method based on the switching table is analyzed,and the original voltage vector is synthesized,so that the direct torque method based on the new voltage vector switching table can suppress the harmonic plane current.The simulation analysis on MATLAB/Simulink verifies the effectiveness of the strategy.Secondly,aiming at the problems of large torque ripple and unstable switching frequency of direct torque method based on switching table,a direct torque control method based on space vector pulse width modulation(SVPWM)is proposed,and the adjacent four-vector SVPWM method and the pre-synthesized vector SVPWM method is analyzed.Based on the direct torque principle and the SVPWM module,the SVPWM-DTC of double-three-phase motor is proposed.In order to further improve the torque response speed,the SVPWM-DTC is improved.The simulation analysis confirms the control performance of the improved SVPWM-DTC under the condition of constant flux and MTPA constraints.Then,based on the mathematical model of dual-three-phase permanent magnet synchronous motor,a finite set model predictive direct torque control strategy is presented,and the control performance and harmonic suppression effect using different voltage vector sets are compared.In order to further simplify the computational complexity,a model predictive direct torque control method based on simplified model and average voltmeter is proposed,and its control effect is verified by simulation.Finally,taking the Microcontroller XMC4500 as the core,the experimental platform of dual-three-phase permanent magnet synchronous motor is designed,the hardware circuit is built and the MCU program is compiled.The experimental results are consistent with the simulation analysis,which verifies the feasibility an d practicability of the above control strategy.