Design Of A Rotor With A Starter-generator Integrated Into An Aero Car

In order to solve the traffic jam caused by the increase of vehicle ownership and the deterioration of road traffic condition,aero car is one of the innovative solutions among others.The pure electric aero car is an important branch of aircraft related technology research and development.As one of the essential components of a new type of aero car,the core component of the electric drive is the motor.The working characteristics of aero-motor are quite different from that of ordinary motor.The rotor is the core component of the motor structure in the design process,so it is of great significance to the design of aeronautical motor rotor.By comparing and analyzing the working characteristics of aeronautical motor and traditional motor,this paper designs the rotor structure of the Halbach array for the one-in-one machine of start-up power generation of aero car,and studies the structure parameters and working characteristics of the rotor array.The details of this article are as follows:(1)The Halbach array structure,which is different from the traditional permanent magnet motor,has many advantages through the in-depth research and analysis of the status research of the permanent magnet motor.Furthermore,the structural characteristics and basic working principle of Halbach permanent magnet array are studied and analyzed,and the basic requirements of high-power density,safety and reliability of aero motor are preliminarily determined.(2)The size parameters of the rotor are determined by the power rating of the motor based on an analytic method;considering the power requirements under various operating conditions to secures the aero car safety can be guaranteed under any operating conditions.The rotor size parameters are further optimized through the peak power of the aero motor to ensure the safety redundancy of the system.(3)Manufacturing a Halbach array structure is difficult.Comparison and analysis of the structure of the aero motor show that the overall structure of the rotor adopts a three-axialsection classic Halbach-array hollow structure,and the rotor magnetic steel adopts a discrete structure and a single magnetic mode,which reduces the processing difficulty of the rotor magnetic steel.The magnetic steel of the rotor adopts the discrete structure and magnetization of a single block,which reduces the difficulty of the processing of the magnetic steel of the rotor.The materials used for each part of the rotor structure are finished.Thus,the initial design of the rotor is complete.(4)In view of the long development period and high manufacturing cost of aero motor,the parameters of magnetic steel thickness,the number of blocks per pole and the magnetic angle of aero motor Halbach array rotor are optimized by Taguchi algorithm.The results show that the rotor structure parameters which meet the requirements of high-power density and high air gap magnetic density of aero motor by combining the finite element method for the experimental group.(5)The finite element method is used to analyze the magnetic flux density distribution of the aeronautical motor under various working conditions.The results show that the motor can produce uniform air-gap flux density at various working conditions and present good sinusoidal periodicity.Furthermore,the axial segment not produce obvious magnetic flux leakage.Finally,considering the eddy current loss of the stator under the rated power generation condition with high-frequency magnetic field,we conduct coupling analysis of electromagnetic and heat flows to verify that the thermal characteristics of the rotor magnetic steel material could meet the requirements for the aero motor.The weight of the rotor structure is calculated,and the results show that the weight control of the rotor material meets the requirements of the high-power density of the aero motor.The overall results show that the three-axial-section classic Halbach-array hollow structure is embedded in the rotating shaft structure.The rotor magnetic steel adopts a discrete structure of 3 blocks per pole and a single 60° magnetic mode.The aero motor rotor with this design can meet the requirements of high-power density and high air gap flux of aero motor,and it can be used in practical manufacture.