Research Of Permanent Magnet Assisted Synchronous Reluctance Motor With Fractional Slot Concentrated Winding

Compared with Synchronous Reluctance Motor(Syn RM),Permanent Magnet Assisted Synchronous Reluctance Motors(PMa-Syn RM)has added ferrite auxiliary excitation.On the one hand,it can increase the inductance difference of d-axis and q-axis and increase the proportion of reluctance torque,thereby improving the low torque density and low efficiency of the synchronous reluctance motor at a lower cost.On the other hand,the power factor of the motor can be improved to improve the utilization rate of the power supply voltage.PMa-Syn RM usually use distributed windings like Syn RM.This paper designs a 10-pole 12-slot PMa-Syn RM with Fractional Slot and Concentrated Winding(FSCW),which reduces the phase coupling and increases the winding Self-inductance can improve the fault tolerance of the motor under shortcircuit faults while having a larger proportion of reluctance torque.This paper uses finite element analysis software to analyze the influence of parameters such as the number of barrier layers,the amount of permanent magnets,the thickness of the magnetic bridge,and the size of the stator slot on the performance of the motor.Three different winding types of motor simulation models were established,namely 10-pole 12-slot PMa-Syn RM with FSCW having alternate teeth wound,10-pole 12-slot PMa-Syn RM with FSCW having all teeth wound,and 10-pole 36-slot PMa-Syn RM with distributed winding.With the same volume and amount of electromagnetic materials,the magnetic field distribution,no-load back EMF,average electromagnetic torque under the control of the maximum torque current ratio(MTPA),reluctance torque ratio,efficiency,inductance of d-axis and q-axis and salient pole ratio;of the three motors are compared and studied.Aiming at the problem of large torque pulsation in the 10-pole and 12-slot with FSCW having alternate teeth wound,the methods of increasing the air gap length,asymmetric rotor barrier structure and stator skew can suppress the torque ripple.An experimental prototype was made,and an experimental platform was established based on STM32F407 and a dynamometer.The no-load back EMF of the prototype and the load characteristics under different currents were measured to verify the correctness of the simulation.