Research On Flux Weakening Control Strategy Of PMSM

Permanent magnet synchronous motor has been widely used in the new energy vehicle drive system due to its excellent torque output and speed regulation performance.Vehicle driving system used to require motor have wide speed range.However,the constant torque strategy only control the motor running under base speed.Flux weakening control strategy that can widen the motor speed range,which has become a research hot spot in the field of electrical drives area.This paper briefly describes the development of permanent magnet synchronous motor control technology,which describe the domestic and foreign research status of the flux weakening control from the motor body and control strategy.It depends on physical structure of permanent magnet synchronous motor to establish the mathematical model of the motor,and describes the principle of vector control in detail.Secondly,this paper describes the theory of permanent magnet synchronous motor flux weakening control,analyses the operating region of permanent magnet synchronous motor and the constraint conditions in the operation of the motor.It is according to the application background of this subject that determined the flux weakening control strategy,under the base speed with MTPA control,while above base speed by join hand in the voltage of the flux weakening control strategy.According to the structure of the flux weakening control block diagram,we come true the flux weakening control of permanent magnet synchronous motor in the Simulink environment,and describes the key modules in the process of simulation in detail,such as current decoupling module,SVPWM module and flux weakening module.The results of simulation prove that the flux weakening control strategy is feasible.Finally,according to the functional requirements of the permanent magnet synchronous motor hardware testing platform.In term of the main circuit,control circuit of core board and driver and the feedback signal circuit of test system have design instructions.Gives the principle diagram of the key circuit,then set up a permanent magnet synchronous motor testing platform.In addition,on the basis of the test platform,with the CCS development environment completed the part of the software and hardware integration test,such as the testing of the open loop SVPWM test,the current loop test and the rotor location method test.All of this research work laid foundation for the further development of the permanent magnet synchronous motor flux weakening control system.