Research On Driving And Fault Tolerance Of Permanent Magnet Synchronous Motor For New Energy Vehicles

In recent years,with the rapid development of the domestic economy,the energy crisis and environmental problems have become increasingly serious.Along with the proposal of "Made in China 2025" and the response to the call for energy saving and emission reduction,new energy vehicle technology has attracted extensive attention and developed rapidly.The permanent magnet synchronous motor(PMSM)has been widely used in the field of new energy vehicles because of its obvious characteristics such as light weight,small volume,large efficiency,high torque density and strong overload capacity.Firstly,this thesis introduces the current mainstream control strategy of PMSM,and according to the basic structure of PMSM,through the derivation and transformation of the mathematical formula,respectively constructs the mathematical model in ABC three-phase natural coordinate system,α-β two-phase static coordinate system,d-q synchronous rotating coordinate system,and the vector control strategy with id=0 is finally selected as the control strategy studied in this thesis.Then,the fault-tolerant topology of three-phase four-leg inverter is designed for the single-phase fault of the new AFFSFT motor,and the feasibility of SVPWM fault-tolerant control algorithm is demonstrated in detail.Based on the special structure of the AFFSFT motor,the fault-tolerant control strategy of auxiliary fault tolerance of excitation winding and speed reduction operation in a specific speed range are proposed,and the simulation test are carried out.After that,on the basis of theoretical analysis,the hardware platform of PMSM control system is designed based on TMS320F28335.The control circuit mainly includes the power supply circuit,JTAG circuit,reset circuit,communication circuit,ADC conditioning circuit,and the power circuit mainly includes the drive circuit and inverter circuit.Finally,on the basis of the simulation test,and based on the real-time digital control system RTU-BOX to build the experimental platform,the system tests were conducted under the normal working conditions and single-phase fault-tolerant conditions,respectively.The results verify the reliability of the whole system and the feasibility and effectiveness of the single-phase fault-tolerant control strategy.