Design And Development Of A System Of A Novel In-wheel Motor With Synthetic-slot Structure For Electric Vehicles

Because of energy shortages and air pollution,electric vehicles(EVs)have become the subject of research in the automotive sector because of their energy-saving and emission-reduction properties.In-wheel direct drive of EVs,which simplifies the transmission system and facilitates flexible control of vehicle dynamics and has a simple and compact structure and facilitate flexible control of vehicle dynamics,has attracted the interest of researchers in the automotive sector.The in-wheel motor with the synthetic-slot structure is also called synthetic-slot magnetic field modulation permanent magnet motor(SSPM motor).In order to improve the torque density,the SSPM motor,which breaks the traditional concept that the stator slot of PMSM only contains windings and insulators,adopts the scheme that permanent magnets(PMs)are put into stator slots,creatively.The SSPM is equipped with two rotors,and rotors are rigidly connected at the end of one side.This motor has the advantages of high torque density and low-voltage large power.This paper focuses on the study of a new type of automotive hub motor with synthetic slots and its driving system.The main works of this paper are summarized as follows:Firstly,the structure of the SSPM motor is studied,and the principle of magnetic field modulation is analyzed in detail.The Maxwell simulation software is used to simulate the model of the SSPM motor.The operating principle of the SSPM motor and the advantages of the synthetic-slot structure are revealed.The simulation results show that the synthetic-slot structure can not only improve the motor performance,but also improve the output torque of the motor and enhance the air gap magnetic density.Secondly,the mathematical model of the SSPM motor in the rotor coordinate system is derived.On this basis,a mathematical model of SSPM motor with the in-phase winding series connection type is derived,and the SSPM motor control strategy based on vector decoupling control is studied.Finally,the hardware design and software design of the SSPM motor system and the design of bench test and vehicle test is introduced in detail,and the proposed motor control strategy is verified.This paper provides a reference for the engineering of a novel SSPM motor and its driving system.