The Control Strategy Of Low Vibration And Noise Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in servo motors,electric vehicles,medical equipment and high grade household appliances because of its high power density.At present,the inverter is widely used in motor,PMSM in the inverter power supply,so the stator current contains a large number of harmonics,and the rotor magnetic field after the armature reaction of the air gap magnetic field will produce a large number of harmonics,resulting in increased electromagnetic force wave harmonic,the harmonic enhancement of motor vibration,noise and unbearable.The purpose of this paper is to reduce the electromagnetic vibration and noise of permanent magnet synchronous motor.The control strategy of reducing the vibration and noise of PMSM was studyed,and the relationship between vibration and noise and harmonic current was analysed.suppression of vibration and noise could be achieved by reducing the current harmonic that can cause vibration and noise.The vector control,random switching frequency space vector pulse width modulation(RSVPWM)and the dead time compensation technology of inverter are studied.In this paper,a hybrid random switching frequency and dead time compensation technique is proposed,and experiments are carried out on the platform of PMSM.The main work of this paper is as follows:(1)The Relationship Between The Vibration and Noise of PMSM and the Current HarmonicsThe relationship between the current harmonics and the vibration and noise of the PMSM is analyzed theoretically,and the purpose of reducing the vibration and noise of the PMSM can be achieved by reducing the harmonic current of the inverter.In this paper,the development and application of control technology of reducing vibration and noise of PMSM are analyzed,and the advantages and disadvantages of control technology about reducing vibration and noise of PMSM from Scholars at home and abroad are compared.(2)Research on Vector Control of Permanent Magnet Synchronous MotorBased on the analysis of the mathematical model of PMSM,the classification and principle of the PMSM vector control method are deeply understood.Then,the basic principle of space voltage vector pulse width modulation(SVPWM)technology and the realization of each part method is explained.(3)Analysis of Random Modulation Technology and Inverter Dead-time Compensation TechnologyThis paper summarizes the classification and mechanism of random modulation technology,and analyzes their advantages and disadvantages.The random switching frequency SVPWM technology is explained from SVPWM technology.The influence of the dead time effect of the SVPWM inverter on the output voltage and current of the inverter is deeply analyzed.Based on the previous research results,the current feedback voltage compensation method is used to compensate the dead time.(4)The Study of Hybrid Random Switching Frequency-dead Time Compensation TechnologyBased on the analysis of the advantages and disadvantages of the random switching frequency modulation technique and dead zone compensation technique,a hybrid random switching frequency dead band compensation technique is proposed.The simulation model of PMSM vector control is built based on Matlab/Simulink simulation software,and the fixed switching frequency modulation,random switching frequency modulation and mixed random switching frequency-dead time compensation technology are simulated.The simulation results show that the advantages of hybrid random switching frequency dead-time compensation technology that combin with the advantages of random switching frequency modulation technology and dead time compensation technology,not only can effectively reduce the low-frequency current harmonic amplitude spectrum,but also can effectively disperse at switching frequency.(5)Experimental Study of Semi-physical Simulation Based on dSPACEA semi physical simulation experiment platform based on dSPACE is built,which is used to verify the experimental results of the random switching frequency modulation technology,dead zone compensation technology and hybrid random switching frequency dead zone compensation technique to reduce the current harmonics.The experimental results show that Random switching frequency modulation technology can effectively reduce the high frequnency harmonics of the switching frequency,and the dead-time compensation technology can effectively reduce the low frequency harmonic current.The mixed random switching frequency-dead zone compensation technique can effectively reduce the harmonic amplitude of low-frequency current and the harmonic current of the switching frequency and the frequency doubling.The experimental results verify the simulation results.To sum up,in this paper,the relationship between the motor vibration noise and the current harmonics of the inverter is theoretically explained,and a new control method is proposed.Through the simulation and experiment results,the mixed random switching frequency-dead time compensation technology that integrate advantages of random switching frequency modulation and dead time compensation technology,effectively reduce the current harmonic amplitude of low frequency and the switch frequency.According to the relationship between current harmonics and the vibration and noise of permanent magnet synchronous motor,the vibration and noise of PMSM could be reduced by reducing the harmonic current of inverter.