Research On Operation Method Of Open Winding Hybrid Excitation Synchronous Motor Drive System Of Electric Vehicle

With the increasing problems of the energy shortage and environmental pollution brought by traditional energy vehicles,clean energy vehicles will be the trend of traffic development in future,which is representative of the electric vehicle with its zero emission pollution-free.How to achieve permanent and reliable operation of the permanent magnet synchronous motor,which is the heart of electric vehicle,became one of the core technologies for the development of electric vehicles.The dual-inverter drive and fault-tolerant control of the open-winding hybrid excitation synchronous motor in the electric vehicle was focused on in this dissertation.The research work is followed:Firstly,in this dissertation,the torque and motion equations of the open-winding permanent magnet synchronous motor were deduced based on the existing electromagnetic theory and the equations of the permanent magnet synchronous motor,and the mathematical model was built as well.On this basis,the mathematical model of the open-winding hybrid synchronous motor was built,which laid a theoretical foundation for the follow-up research on the control and simulation of the open-winding hybrid field motor.Secondly,the dynamic performance of the hybrid wound synchronous motor was studied with simulation in Matlab.The rotor flux direction control algorithm,id being zero,was proposed to improve the driving control,which used the traditional voltage space vector pulse width modulation strategy and based on the theory of field weakening to study the feasibility of the high-speed zone weakening control of the motor.Whether the excitation current of the open winding HESM is energized was analyzed with simulation in Matlab,and the difference of the dynamic response speed of the motor was analyzed based on it as well.Thirdly,the fault-tolerant drive control scheme of the open winding HESM was studied with simulation.In order to ensure that the motor can maintain high reliability and safety under the harsh conditions,the dissertation put forward the fault-tolerant scheme of fast isolating fault device to realize fault-tolerant operation of the motor with the fault condition of the power switching device which may be broken or shorted,which ensured that the dual inverter drive was switched to a single inverter drive in the case of an inverter failure and kept the motor torque output.On this basis,the simulation was done to prove that the proposed fault tolerance scheme was feasible.Finally,on the basis of the above theoretical simulation,the hardware system of dual inverter with open-winding motor was built with STM32F407 microcontroller as the core,including signal conditioning circuit and driver circuit.The related program was designed,such as A/D sample,detection of the position speed and other program modules.In the end,this dissertation achieved a low-speed torque control based on double closed-loop control,and verified the reliability of the speed closed-loop by detecting the stator current cycle.