Design Of Dual-Motor Direct Drive Speed Control System For Pure Electric Buses

In order to alleviate the dilemma of the global energy crisis and the deterioration of the ecological environment,countries in the world will give priority to the development of new energy vehicles and pure electric vehicles.According to " the 13 th Five-Year Plan" medium and long-term development plan and the " intelligent manufacturing in China 2025" short-term goal,pure electric vehicles will become the dominant direction of future car development.In this paper,the current drive system of pure electric buses have the disadvantages of low specific power of drive motor,long transmission chain,low working efficiency,large structure space,low lightweight degree,and so on.so It proposes a dual motor combined drive pure electric buses driver and the topological structure of a12/26-pole Flux-switching Permanent Magnet synchronous main motor.The speed-regulating mechanism studied the transmission principle,structure composition,parameter matching and control strategy of the pure electric buses driven by the two motors.Put forward a dual-motor combined drive and speed-regulating mechanism for a pure electric buses with a total power of 150 kW.Design the transmission principle and system components of the drive speed-regulating mechanism.Analyze the characteristics of the whole vehicle's power and resistance power in typical driving conditions such as acceleration,climbing,and high-speed driving.Formulate the power distribution and combination scheme under different working conditions,and Complete the matching of the performance parameters of the main motor and the speed-regulating motor and the powertrain parameters.ultimately determine the power of the main motor and the speed-regulating motor as 100 kW and 50 kW.A new type of multi-pole switching flux permanent magnet synchronous motor for pure electric buses was developed,and analyze its topological structure and principle of flux switching.The size parameters of the primary and secondary motors are obtained from the motor design formulas.Electromagnetic simulation models of 12/26-pole main motors and12/10-pole speed-regulating motors are established through finite element analysis ofelectromagnetic fields.The influence of the parameters on the dynamic characteristics of the motor's electromagnetic field is analyzed,including the width of the rotor tooth width,the permanent magnet size and the width of the stator slot.as a variable factor of the motor structure parameters,set up an optimization scheme of the magnetic field no-load characteristics,and a method to optimize the torque fluctuation of the groove was proposed.The torque ripple of the main motor was optimized after the optimization.the reduction of 68.9%,the use of permanent magnets was reduced by 9.6%,and the phenomenon of magnetic field saturation of the motor was effectively reduced;the cogging torque ripple of the secondary motor was reduced by 60%,the amount of permanent magnets was slightly reduced,and the stability of the motor was improved.The secondary motor test prototype was eventually developed.By the structural parameters of the drive speed control mechanism of a pure electric buses Establish the 3D model of each drive assembly,and Complete the virtual assembly of a direct drive dual-motor drive structure for a pure electric buses,and there is no interference between the transmission parts and the assembly is reasonable,The overall structure of the drive system meets the space design requirements.