| High-power low-speed direct-drive line-start permanent magnet synchronous motor(PMSM)has many advantages such as simple structure,small size,high efficiency.But,influenced by stator slots and rotor slots as well as multi poles and few slot of the motor,the harmonics contented in air-gap are large and affect motor's characteristics seriously.Winding arrangement of 315kW 36 slots 30 poles motor is designed and analysed.Structure and size of the motor is also designed.Then,by means of time-stepping finite element method(T-S FEM),dynamic process of the motor is simulated,and influences on torque by main design parameters of high-power low-speed line-start permanent magnet synchronous motor are studied specially.These works can provided some theoretical foundations for further studying on this kind of motor.Main contents of this paper are as follows:1)In accordance with basic windings theory of A.C.machines,the motor with multi-pole and few-slot is analysed.Then 36 slots 30 poles motor's winding arrangement is designed by means of star-diagrams of the slot potential,and the winding factors of each harmonic emf of this winding arrangement are worked out.2)Structure and size of high-power low-speed line-start permanent magnet synchronous motor is designed,and the model for simulation is built by ANSYS.Then,using the T-S FEM,starting process and operation performance are simulated.Then,making use of the model of asynchronous motor without permanent magnets,the designed motor is checked.3)Influences on dynamic and steady torque with different air-gap length,different the number of slot on rotor pole shoe and different stator slot width are studied by means of T-S FEM.General rules of influences on torque with design parameters are obtained.4)Conclusions of torque studying are as follow:Torque ripple can be restrained by slotting on pole shoe;Increasing length of air-gap can weaken torque ripple;Torque ripple does not decrease with shortening of the stator slot notch width. |
PDF Full Text Request