Study On Control Methods Of Permanent Magnet Synchronous Machine For Electric Vehicles

EVs are energy-saving and environmental means of transportantion. In China,since abundant permanent material, PMSMs are used widely in EVs withperformance advantages. Different from industrial speed control system and positionservo system, EV drive machine system has the characteristics of high torque controlaccuracy, efficient energy feedback and complicated operating environment. This thesisfocuses on the control methods of PMSM, especially study on the machine invertordesign and control strategies.At first, the beneficial factors of PMSM for EVs are indicated. Based on thesummary of advanced EVs’ drive machine selection, regionals differences are analysed.Control methods of PMSM are summarized and compared. Focusing on the twotechnical problems, i.e., torque ripples and wide speed range, this thesis presents thehigh-performance control techniques which are the theoretical basis of the study on thecontrol strategies of PMSM for EVs.Secondly, mathematical models of PMSM in different coordinate systems are builton the basis of Parker Transform and Clark Transform. The application characteristicsof each model are analyzed. Based on the demands of EVs, a novel control strategy ofPMSM is presented. PWM methods of vector control are analysed, then, a novel currentfeedforward compensation method is presented to restrain the hysteresis of currentvector while applying the Hysteresis Band Pulse Width Modulation (HBPWM).Furthermore, the simulation model of PMSM in MATLAB Simulink is built. Thesimulation results show that the proposed strategy is feasible and can provide the basisof experimental studies.Then, using IGBT as power switching device, three-phase full-bridge invertercircuit of the machine controller is developed. In addition, using digital signal processorTMS320F28335and decoding chip AD2S1205as the core, the control circuit ofmachine controller and the resolver driving-decoding circuit are developed. Thehardware system meets the demands of machine driving and EVs.In the Code Composer Studio IDE, applying field oriented vector control andSVPWM, the control program of PMSM for EVs is coded in C language. With highreadability of the main program and high portability of the peripheral interrupt subroutine, flexible application is obtained when the proposed program is transplantedinto other machine controller.Finally, an experiment platform for the PMSM for EVs is designed. The platformmeets the testing damands of PMSM drive system hardware, as well as the debuggingdemands of software. The performance of the developed machine controller system istested on the platform. The results show that the proposed machine controller achievesthe design requirements of EV and AC machine. The results also verify that theproposed software can realize the high-performance control strategies of PMSM,meeting the demands of EV’s driving. The testing platform, motor controller andsoftware system, which are developed in this thesis, provide preconditions for furtherstudy on control strategies of PMSM for EV.