Research On Low Noise Control Strategy Of Interior Permanent Magnet Synchronous Motor

With the advancement of society and technology,people are no longer just satisfied with the role of new energy vehicles in mitigating energy and environmental problems,and have begun to put forward higher requirements on their driving performance and driving experience.However,this will aggravate the vibration and noise of permanent magnet synchronous motors.Therefore,this paper mainly studied the low noise control strategy of interior permanent magnet synchronous motor for electric vehicles.Firstly,the analytical expression of the radial electromagnetic force of the permanent magnet synchronous motor was derived under the premise of ignoring the magnetic saturation,and the low-order electromagnetic force order and frequency characteristics,which play a major role,were analyzed.The finite element software was used to simulate the radial electromagnetic force of the interior permanent magnet synchronous motor,and the results of analytical method and finite element method are basically consistent.Secondly,the mathematical model of the interior permanent magnet synchronous motor drive system was established.According to the maximum torque-current ratio curve and the voltage ellipse limit curve,the corresponding relationship between the rotational speed,the command torque and the current was obtained through the electromagnetic simulation data correction,and the basic drive system simulation model was built in the Matlab/Simulink environment.There are 5 times and 7 times current harmonics in the stator winding.It was found that these two current harmonics mainly produce 4 times frequency and 6 times frequency motor radial electromagnetic force.A parallel resonant regulator was connected to the conventional PI controller of the interior permanent magnet synchronous motor to suppress a specific current frequency,and an improved simulation model of the motor drive system was built.At the same time,based on the field-circuit coupling analysis method,the Simplorer,Matlab/Simulink and Maxwell coupled simulation analysis models of radial electromagnetic force were established.The simulation results show that the improved motor control strategy can effectively suppress the 5th and 7th current harmonics,which reduces the 4 times frequency radial electromagnetic force by about 46.9%,and the 6 times frequency radial electromagnetic force was reduced.1.8%.4 times the frequency of the radial electromagnetic force amplitude is larger,the weakening effect is obvious,and the 6 times frequency amplitude is relatively small,and the degree of weakening is relatively low.Finally,considering the difference between the simulation model and the actual working conditions,the interior permanent magnet synchronous motor vibration and noise test platform was built,and the vibration and noise test was used to analyze the vibration and noise.The test results show that when the load is 10 N?m,the noise of the interior permanent magnet synchronous motor at 4 times and 6 times was reduced by 2.4% and 3.2%,respectively,and the vibration amplitude was reduced by 62.5% and 32% respectively.When the load is 50 N?m,the noise of the interior permanent magnet synchronous motor at 4 times and 6 times was reduced by about 2.4% and 7.2%,respectively,and the vibration amplitude was reduced by 34.7% and 24.9%,respectively.Aiming at the vibration and noise problems of the interior permanent magnet synchronous motor drive system for electric vehicles,this paper proposed a control strategy that suppresses the specific radial electromagnetic force of the motor and reduces its vibration and noise by suppressing the current harmonics.This method can effectively reduce the vibration and noise of the MTPA interior permanent magnet synchronous motor using the look-up table method,and improve driving comfort.