Study On Torque Ripple Suppression Strategy Of Permanent Magnet Synchronous Motor

With the wide application of permanent magnet synchronous motor(PMSM),it is required that the PMSM can be used in high precision situations.When the motor is suddenly loaded on the outside,it will bring great impact to the whole system.The torque ripple is caused by torque and speed ripple,so the demand for the smoothness of motor output torque is higher and higher.The torque ripple of PMSM is mainly caused by the tooth slot torque and harmonic torque.At present,there are only two ways to solve the problem.One is to optimize the motor body,the other is to improve the control strategy.This thesis introduces the basic working principle of PMSM and three common mathematical models,enumerates the advantages and disadvantages of several vector controls,and analyzes the realization principle and method of SVPWM in detail.Then the causes of harmonic torque and grooving torque are analyzed and the mathematical harmonic model of PMSM is established.Then the control strategy of harmonic current is put forward to suppress the torque ripple of the motor.Under the rotation coordinate axis,the harmonic voltage is injected to offset the harmonic component produced by PMSM in the current loop.It can restrain 5th and 7th harmonics very well.PI repetitive compensation controller is a series of PI controller and repetitive controller,and then parallel to the repetitive controller.In the speed loop,the tracking effect of the speed loop is improved by this way,and the speed pulsation caused by the disturbance in the system is also reduced.Based on the above two control strategies,the effectiveness and feasibility of the algorithm are verified by modeling and simulation in MATLAB/Simulink.The main control chip uses DSP TMS320F2812.The hardware system module,software system scheme and related flow chart of PMSM driver controller are designed preliminarily.