High-efficiency line-start interior permanent-magnet synchronous motors

This paper presents a successful design of a high-efficiency small but novel interior permanent-magnet motor using NdBFe magnets. It is designed to operate both at line and variable frequencies. Line start with high inertia load was a special consideration. Time-stepping finite-element analysis has been used to successfully predict the dynamic and transient performances of the prototype motors. It has been found that the proposed design has yielded successful simulation and experimental results. The maximum load inertia corresponding to the rotor-bar depth has been determined from the simulation results.