Current Harmonic Suppression Strategy Of Induction Motor Vector Control System

In the research field of high performance induction motor,the harmonic problem of the motor system is urgent to be solved in order to further improve the control accuracy and operation stability of the motor.Domestic and foreign Inovance Technology,Schorch and other motor drive scheme manufacturers have also invested in its research.In this paper,the problem of eliminating torque ripple caused by harmonic current in induction motor is studied.First,set up the mathematical model of three-phase induction motor under different coordinate system,steady-state harmonic three-phase induction motor mathematical model is established,and based on dirichlet convergence condition for current Fourier transform,the induction motor electromagnetic torque is derived and the relationship between the current harmonic,affected by harmonic current output torque and affect the motor speed to reduce the Control performance of the system and therefore,in view of the current harmonic frequency for the mathematical characteristics of base wave frequency doubling,the introduction of repetitive Control(Repectitive Control,RC)current harmonics.Secondly,the principle and design principle of repetitive control in vector control system of induction motor are analyzed,and the inherent defects of repetitive control are pointed out.First,when the system is disturbed by step,such as sudden loading and unloading,acceleration and deceleration,the dynamic performance of the motor system will be reduced due to the delay output control signal due to the delay characteristic of the internal mode.Therefore,the nonlinear controller Tornambe controller(TC)based on active compensation is introduced.In addition,the basic principle of Tornambe controller is introduced in detail,a two-phase synchronous rotating coordinate system(dq)motor model is established,and in order to reduce the difficulty of parameter design,the feedback linearization dynamic decoupling technology is used to decouple the current loop nonlinear TITO system into SISO single variable system.The parameter law of the Tornambe controller is studied bysimulation,and the extended state observer in the Tornambe controller is used to improve the robustness of the system.In order to improve the dynamic response speed of the system,a feedforward channel is added to solve the problem of repetitive controller response delay.The harmonic suppression strategy of induction motor based on repetitive Tornambe control(RTC)is designed by the controller method.The small gain theorem is used to analyze the stability of the system,and the algorithm is verified in MATLAB/Simulink.Finally,In Altium Designer16,I drew the inverter circuit,IGBT drive protection circuit,off-chip AD sampling circuit,TMS320F28335 chip control circuit and isolation detection circuit.In CCS6.0,vector control,speed detection,off-chip sampling,current harmonic suppression algorithm C program is prepared.The software and hardware experimental platform of induction motor vector control system is designed.