Research On Improved Quasi Z-source Drive Technology For Suppressing Torque Ripple Of BLDCM

Brushless DC motor(BLDCM)is widely used in industrial automation,aerospace,household appliances,new energy vehicles,office automation,artificial intelligence and other fields because of its simple structure,large torque,easy control method and good speed regulation performance.However,different from the sinusoidal current drive of permanent magnet synchronous motor,square wave driven BLDCM not only outputs a large load torque,but also brings a large torque ripple,which will cause vibration,resonance,noise and even damage to the motor during the operation of BLDCM.In recent years,new topological DC converters have been added in the front stage to adjust the DC bus voltage during phase change and drive BLDCM.This dissertation for the BLDCM torque ripple generated several reasons were analyzed,and through the mathematical model of BLDCM,under the condition of ideal counter electromotive force of the exchange of several kinds of phase current happen during phase are analyzed,and the commutation torque ripple under ideal counter electromotive force,this dissertation puts forward the improvement of BLDCM torque ripple source of improved quasi Z-source drive technology,based on the improved quasi Z-source inverter topology,design the corresponding control strategy of drive technology,the original can only booster cannot step-down quasi Z-source inverter converter,can be in the output switch between high and low voltage,It not only satisfies the dynamic performance of BLDCM that can be adjusted in a wide speed range,but also restrains the torque ripple of BLDCM during the phase change.In the simulation platform of MATLAB/Simulink,model building was carried out for the improved quasi Z-source drive technology that inhibits BLDCM torque pulsation.Feasibility test and software in-loop test were carried out for the built model based on model design,and hardware in-loop test was carried out after the automatic generation of control code.The main modules including improved quasi Z-source inverter module,the back emf zero crossing detection module and so on carries on the description,the simulation results with brushless motor in the traditional regulating speed system,PWM chopper speed regulation system of torque ripple,proved that inhibition of BLDCM torque ripple and improve quasi Z-source drive technology feasibility and the superiority in terms of torque ripple suppression.