Research On Vector Control Stragegy For Permanent Magnet Synchronous Motor Of Hybrid Electric Vehicle

At present, hybrid electric Vehicle is one of the mainstream area ofthe research on new energy vehicles. Motor drive systemis act as itscritical technologies, whose performance will influence the wholevehicle’s dynamic performance and fuel consumption performancedirectly. So it has practical significance to make an in-depth researchtowards the motor drive system.Firstly, this thesis introduces the mathematical models of permanentmagnet synchronous motor, the principles of vector control and thecommonly used control method for PMSM. Then it makes a specificexplanation towards the elaborated principles of space vector pulse widthmodulation (SVPWM) which is commonly used in vector control. Thisdissertation focuses on research the voltage coupling problem whenPMSM governing system in a dynamic process, and compared threedynamic decoupling strategy: the current feedback decoupling control,IMC and error compensation decoupling control. Current feedbackdecoupling control compensated the coupling components output ofcurrent controller via feedback, this method was easy to realize, but itdepends highly on the accuracy of the motor parameters; IMC based onthe theory of internal model control less dependent the motor parameters;Although error compensation decoupling control as a mixed structure ofdirect control and cross-coupling control is complex, it has welldecoupling effect with strong robustness to the motor parameterestimation errors. Simulation results confirmed the effectiveness of thedecoupling control strategy.Owing to parameters varying with time and non-linear when motordrive system running, the common PI control can not be in a variety ofconditions to achieve design performance, the dissertation used fuzzy PIparameters self-tuning control method in the speed loop, canadjustmented the PI parameters in real-time depending on speed error andits rate of change. when the motor is running can get a better dynamicresponse analysis of the simulation results of the two control methods, confirmed the superiority of the fuzzy adaptive PI control. Finally, themain structures of the software and hardware parts of the the electricdrive system motor controller are introduced. Principles and realization ofthe main functional blocks of these two parts are also illuminated. Thesoftware flow chart of overall system and the work flow chart of interruptsubroutine are designed.Through the theoretical analysis and simulation studies, the thesisverifies that it is correct and effective for the author’s method of vectorcontrol towards the PMSM drive system. All of these laid the foundationfor the further study of the system.