Design and Optimization of a Two-Pole Line-Start Ferrite Assisted Synchronous Reluctance Motor

To meet the new international efficiency (IE) standards, a 2-pole multi-barrier line-start ferrite assisted synchronous reluctance motor is proposed for a bore-well submersible water pumping application. Low-cost ferrite permanent magnets (PM) are used instead of the costly rare-earth magnets to make the motor economically viable while being efficient. Further, a multiple rotor flux-barrier is employed with a simple cage and end-ring geometry which minimizes the number of rotor bridges. This also eases the process of embedding the magnets in the flux barriers. The rotor flux barriers are designed to maximize the reluctance torque while protecting the ferrite magnets from demagnetization due to the in-rush currents. To ascertain these claims, a 2-D finite element (FE) analysis is carried-out and the results are presented. Later, the initial rotor geometry is optimized using FE analysis to further improve the motor performance.