Principle Of Magnetic Flux Regulation Analysis And Design Of An Auto-rotary PMs Mechanical Flux-varying PM Machine

By introducing the method of mechanical flux-adjusting into permanent magnet(PM)machine and combined with the advantage of interior PM synchronous machine(IPMSM),a new type of auto-rotary PMs mechanical flux-varying PM machine(ARPMMFVPMM)is creatively proposed in this paper,which is contraposed the problems that the air-gap magnetic field of the PM machine is difficult to neatly regulate.The ARPMMFVPMM is the synthesis of IPMSM with mechanical flux-adjusting device(MFAD),not only can it overcome the insufficiency of mechanical flux-adjusting machine,but also the ARPMMFVPMM have many advantages such as simple structure,reliable running,high torque density and good ability of magnetic field regulating.Based on researching the principle of operation and magnetic flux regulation,mechanical dynamics was analyzed by virtual prototype technology,electromagnetic property and magnetic field adjustment capacity were calculated by stable magnetic field and transient magnetic field in ANSYS/Maxwell.The main works and achievements of this paper are as follow:1.The structure and the operating principle of ARPMMFVPMM.Based on IPMSM which applied in Toyota Prius 2004 electric vehicle,using cylindrical PMs to replace oblong PMs.The main flux linkage can be weakened and the magnetic field distribution can be changed by transforming the magnetizing direction of the PMs.2.The structure and the operating principle of MFAD.Two type of MFAD were proposed,one could make PMs in each pole auto-rotating,the other could make PMs in half pole autorotating.The operating principle of MFAD is when it synchronously rotated with rotor,there would be a centrifugal force in sliding block,which made gears auto-rotating.The transmission shaft between gears and PMs makes PMs synchronously rotated with gears.3.Mechanical design and dynamics simulation.Designed the parameter of each component in MFAD to realize continuously transmission.The deformation of spring in different speed was obtained by virtual prototype technology.4.Optimum structural design.The parameter of magnetic barriers was optimal designed to reduce magnetic flux leakage.Meanwhile,the parameter of stator slot was optimal designed to reduce back-EMF harmonic and cogging torque.5.Analysis of electromagnetic property.The electromagnetic property was calculated at basic speed without adjusting PMs,above speed with adjusting 4 poles PMs,above speed with adjusting 8 poles PMs.The magnetic field distribution,flux density in air-gap,flux linkage,induced EMF,the armature winding self-inductance and mutual inductance,d-q axis inductance and loss were calculated,the relationship between PMs auto-rotary angle and flux-weakening level was obtained.The analysis indicates the rationality of design,the magnetic field can be effectively adjusted by MFAD,achieving the effect of constant voltage generation.