Research On Efficiency Optimization Control Strategy For A Hybrid Excited Axial Field Flux-Switching Permanent Magnet Machine

Hybrid excited axial field flux-switching permanent magnet(HEAFFSPM)machine is a novel stator-excitation hybrid excitation machine.Due to short axial length,high torque density,low-speed large-torque capability and wide constant power operating range,the HEAFFSPM machine is excellent candidate for a wide speed and large torque operating application such as electric vehicles.In this thesis,to realize low-speed large-torque and high-efficiency wide-speed operation,the coordination principle between the loss as well as efficiency and the current of the HEAFFSPM machine drive system is investigated.This will provide theoretical basis and technical support for the applications of the HEAFFSPM machine in the distributed drive electric vehicles.Firstly,the research background,status and significance are introduced.The topology,operating principle and flux modulation mechanism of the HEAFFSPM machine are analyzed in details.The mathematical model of the HEAFFSPM machine is established.The simulation model is built and verified.Secondly,three kinds of current vector control strategies including only the id=0,flux-weakening and minimum copper loss control for the HEAFFSPM machine are investigated.The validity of the above-mentioned control strategies is verified by the simulation analysis.To further improve the operating efficiency of the drive system,a novel efficiency optimization control sltrategy for the HEAFFSPM machine is investigated.The mathematical model considering the copper and iron losses is derived and the efficiency optimization control system of the HEAFFSPM machine is established.Coordinating control principle of the armature current and excitation current under different operating conditions is investigated to achieve a minimum loss operation.This will enhance the load capability and broaden constant power operation range as well as improve the efficiency of the drive system.Finally,an experimental platform based on the MicroLabBox is designed.The effectiveness of the control strategies such as the id=0 control,minimum copper loss control and efficiency optimization control is validated.Meanwhile,the flux-enhancing and flux-weakening characteristics of the HEAFFSPM machine are tested.