Comparison And Analysis On Performance Of Axial Flux And Radial Flux Permanent Magnet Generator For Range Extender

The appearance of range extender not only reduces the pollution emission content of fuel vehicles,but also increases the cruising range of pure electric vehicles.The range extender plays an indispensable role in extended range vehicles.In the range extender,the rotor of the flat axial flux permanent magnet generator can replace the flywheel of the fuel engine,which not only simplifies the structure of the range extender,but also reduces the system quality,and has become one of the development directions of the range extender generator.Some literatures have proved that axial flux permanent magnet motor has higher power density than radial flux permanent magnet motor in electric operation.However,whether the electromagnetic performance of axial flux permanent magnet generator is more advantageous in power generation operation needs further study.The main research contents of this paper are as follows:Firstly,the electromagnetic design of axial flux permanent magnet synchronous generator is studied.The influence of different pole slot matching on no-load back EMF waveform distortion rate,cogging torque,output voltage and current harmonic content,output power,power density and total material quality of axial flux permanent magnet synchronous generator is analyzed.The method of weakening cogging torque with 18 slots and 12 pole slots and the influence of auxiliary slots on generator output power and power density are studied.Secondly,the no-load and load performance of axial flux permanent magnet generator and radial flux permanent magnet generator are compared and analyzed.The influence of pole arc coefficient from 0.6 to 0.8 on no-load back EMF harmonic and magnetic leakage coefficient of radial flux permanent magnet motor is analyzed.The effects of different pole slot matching and different rotor structure on cogging torque,power density,voltage adjustment rate and effective material consumption of radial flux permanent magnet generator are studied.The no-load,load performance and iron loss of axial flux magnet generator and radial flux permanent magnet generator are compared.Then,the influences of controllable rectification and uncontrollable rectification on magnet generator efficiency and DC output voltage and power are studied.Three-phase uncontrollable rectifier circuit and double closed-loop vector control system are built by Maxwell simplorer module.The influence of uncontrollable rectifier on voltage harmonics,current harmonics,loss,efficiency and air gap magnetic density of axial flux permanent magnet generator and radial flux permanent magnet generator is studied.The influence of controllable rectification on the output voltage,current and power of axial flux permanent magnet generator and radial flux permanent magnet generator at DC side,and the current components,phase voltage and phase current,loss and efficiency at AC side were studied.Finally,the internal temperature distribution of axial flux permanent magnet generator is studied.Solve the heat dissipation parameters of each component material of the generator,and simplify the model by equivalent calculation of the winding;The waterway design of axial flux permanent magnet synchronous generator is carried out by Solidworks The influence of water flow direction and water flow velocity from 0.5m/s to 5m/s on the heat dissipation performance of motor is studied In order to verify the rationality of the designed waterway and whether the generator design meets the insulation requirements,the Ansys Fluent module is used to analyze the internal temperature field distribution of the motor under different water flow rates,and a prototype is made for temperature rise test.