Current Harmonic Suppression Strategy For Permanent Magnet Synchronous Motor Based On Improved Deadbeat Predictive Contro

Permanent Magnet Synchronous Motor(IPMSM)is widely used in electric vehicle drive systems due to its high-power density and wide operating speed range.In the actual operation of PMSM,non-ideal factors such as the dead time effect of the inverter and the non-sinusoidal flux linkage of the permanent magnets will lead to rich current harmonic components in the motor system,which will generate unnecessary motor losses and affect the running quality of the motor.Therefore,suppressing current harmonics plays an important role in ensuring stable operation of the motor system.In this paper,the mathematical model of PMSM in ideal state is established firstly,and the mathematical model of PMSM containing harmonics is established by analyzing the causes of current harmonics.Secondly,the theory of multiple synchronous rotating frame transformation commonly used in current harmonic suppression strategy is introduced,and the shortcomings of traditional current harmonic extraction methods using low-pass filter or current average method to extract current harmonics are analyzed.A current harmonic extraction method with simple structure,easy implementation,higher extraction accuracy and faster dynamic response speed is proposed by optimizing and reconstructing the structure and input quantity of the filter.Thirdly,in view of the shortcomings of the traditional current harmonic control method based on PI controller,a current harmonic control method based on Deadbeat Predictive Control(DPC)is introduced.Then,the problem that the current harmonics cannot accurately track the given value 0 due to the model error generated by the traditional DPC when the motor speed is high and the problem of poor robustness are analyzed.The Improved Deadbeat Predictive Control(IDPC)model is established by improving the solution method of PMSM state equation and considering the effect of rotor position changes in one control cycle and applying the method of current static error elimination.At the same time,a current harmonic control method based on IDPC is proposed,and a current harmonic suppression strategy based on IDPC is formed together with the proposed current harmonic extraction method.Finally,the feasibility and effectiveness of the proposed strategy are verified on the MATLAB/Simulink simulation platform and a set of 40 k W PMSM experimental platform respectively.The simulation and experimental results show that the proposed strategy can effectively suppress the current harmonics when the motor runs at low,medium and high speed and the parameters are mismatched.