Research On Low Torque Ripple Of Open Winding Permanent Magnet Synchronous Motor Direct Torque Control

PMSM has the advantages of high reliability and high control accuracy.It is widely used in robot servo control and aerospace and other fields,but its performance is increasingly unable to meet the rapid development of modern industry.The open end winding PMSM system is proposed and is widely used in electric vehicles and other fields.As a high-performance control strategy,the direct torque control strategy has simple control principles,good robustness and excellent fast dynamic response performance,and has also received extensive attention from scholars.This paper analyzes the electromagnetic theoretical model of the open-winding PMSM system,and uses the direct torque control algorithm to control it to reduce torque ripple and improve the operating characteristics of the motor system.The zero generated by theoretical analysis,simulation calculation and experimental research The sequence current is suppressed,and efforts are made to reduce the torque ripple of the direct torque control algorithm to achieve go od control of the open-winding PMSM system by the direct torque control algorithm.Establish a mathematical model of an open-winding PMSM system based on dual inverter control,analyze the feasibility and superiority of the direct torque control algorithm based on this model,and visually describe the work of the control algorithm through the voltage vector diagram principle.In order to reduce the torque ripple,the zero sequence current generated by the common DC bus open-winding PMSM system must be suppressed,the phase current waveform is improved,and the zero sequence loop is determined by analyzing the cause;according to the zero sequence current generation The reasons are different.The back-EMF harmonic suppression and the zero-sequence voltage suppression are performed separately.For the zero-sequence voltage generated by different voltage vectors,the zero-sequence voltage is suppressed to achieve the optimal effect.According to the analysis of the causes of direct torque ripple,the dual-inverter open-winding PMSM system has the characteristics of multiple voltage vectors,and the methods of 12-sector,five-level torque hysteresis and deadbeat predictive control modulation are used respectively.The torque ripple is suppressed,and the optimal control method is obtained through comparative analysis.We use the experimental results to prove the correctness and accuracy of the algorithm,use computer software for modeling and simulation,and optimize the simulation parameters.Finally,by comparing the simulation results with the experimental results,we get the same conclusion as the simulation.