Research On A Flux-variable Partitioned Stator Permanent Magnet Claw-pole Machine

It is a hot topic to widen speed range of permanent magnet machines in recent years.Since the magnetic field is produced by magnets,it is very hard to regulate after the machine is built.When the PM machine is used as a motor,the range of speed regulation is quite narrow.Applied in generators,voltage is difficult to change for demagnetization of PM is a tough issue.On usual occasions,d-axis current is imposed in winding coils of stator to cut the magnetic field in the air gap to increase the range of speed,which leads to irreversible demagnetization of PM.A novel flux-variable partitioned stator permanent magnet claw pole machine is proposed.The magnetic field is produced by memory permanent magnet materials,whose magnetization level can be changed just by current pulse,no longer constant current.The loss of machine is going down while the speed range is increased.First,structures of the flux-variable partitioned stator permanent magnet claw pole machine is analyzed.According to the form of field generation,the structures can be divided into serial and parallel structures.Flux leakage cannot be ignored in the design of claw pole machine.Thus,the calculation of flux leakage is derived to figure out the leakage route in magnetic field.Then,the regulation and ability of magnetic field is studied.The B-H curve of Al Ni Co magnet is the priority part in the machine for the effective linear control range.In on-load and no-load situations,the analysis of field regulation of three different structures is conducted for the normal law of flux-variable partitioned stator permanent magnet claw pole machine.Moreover,the relationship of claw-pole shape and flux leakage is deep discussed for the choice of claw shape.The flux leakage of the proposed machine can be changed by the major design parameters of claw pole shape.According to the law found during the optimization,the most vital parameter is figured in later machine design.Finally,performance characteristics are calculated.The performance consists of the output torque of machine and losses.During the calculation process,the reason for torque ripple is researched and cogging torque is figured out.Comparison of flux-variable partitioned stator permanent magnet claw pole machine and original electrical claw pole machine is conducted to make sure the high effectiveness.