| The worldwide pressure of resources and environment makes the battery electric vehicle not only in our country,but also in the world,with great potential for development.For the field of new energy vehicles,permanent magnet synchronous motor(PMSM)has become the mainstream of the driving core with its excellent performance.The smoothness of the motor output torque,as well as the impact of noise is an important measure of the performance of electric vehicle products.The high-order harmonic of PMSM stator current is the main reason for torque ripple.Therefore,the research on optimal control strategy of PMSM stator current is of great significance for reducing torque ripple and improving the running performance of electric vehicle.According to the mathematical model of PMSM,vector control theory and space vector pulse width modulation(SVPWM).On the basis of the vector control strategy based on the maximum torque-per-ampere(MTPA),An optimal control strategy is proposed to eliminate the high-order harmonic currents in the stator of the motor by harmonic voltage compensation.First,the causes of harmonic generation of PMSM are analyzed from the aspects of inverter nonlinearity and motor structure.Through mathematical modeling and simulation analysis,it is concluded that 5th and 7th harmonics are mainly produced in the motor,and the mathematical model of high order harmonic of PMSM is established.Secondly,a new control strategy for optimizing the stator current is proposed.The algorithm extracts the high order harmonic components in the stator current of the motor in real time.Using the coordinate transformation principle and the harmonic voltage formula,the voltage of the d-q axis of the system is compensated,and the closed loop control of harmonic current is formed.The harmonic component of the stator current is counteracted,which realizes the optimization of the stator current wave form,effectively suppresses the output torque ripple and improves the stability of the motor.Finally,the simulation model of each module and the motor speed control system based on the algorithm are built under the MATLAB/Simulink platform.The effectiveness of the simulation experiment is verified by comparing the results of the simulation experiment.On this basis,the control experiment platform of PMSM based on TMS320F28335 is designed.Based on the bench test,the stator harmonic optimization control strategy of PMSM is experimentally studied.By comparing the experimental waveforms,it is verified that the algorithm is feasible for restraining the motor torque ripple and improving the stator current waveform. |
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