Optimal Design of an Interior Permanent Magnet Synchronous Motor with Cobalt Iron Core

Abstract

The use of cobalt-iron (VaCoFe) core is investigated as an alternative to silicon-iron (FeSi) on the design of interior permanent magnet synchronous motors (IPMSM). A spoke-type IPMSM geometry is optimized considering FeSi and VaCoFe cores for a torque range up to 40 N.m, providing a general comparative analysis between materials, considering the application of a 4-motor competition vehicle’s powertrain. A genetic optimization algorithm is applied over a hybrid analytical/finite-element model of the motor to provide sufficiently accurate electromagnetic and thermal results within a feasible time. VaCoFe can result in an estimated increase of up to 5 % in efficiency for the same torque, or up to 64 % torque increase for the same efficiency level. After optimization, and using a detailed time-dependent model, a potential 3.2 % increase in efficiency, a core weight reduction of 4.1 %, and a decrease of 9.6 % in the motor’s core volume was found for the VaCoFe at 20 Nm. In addition, for the same motor volume, the VaCoFe allows an increase of 51.9 % of torque with an increase of 1.1 % of efficiency, when compared with FeSi.

Low-cost variable-speed wind turbines design by recycling small electrical machines. Arrangement of permanent magnets in the rotor

“…The decreasing cost of SmCo and NdFeB permanent magnets and their availability in the market has caused permanent magnet synchronous generators to be widely used in small applications. On the other hand, Zhao et al [19] and Bhagubai et al [20] propose the optimal design of a permanent magnet synchronous generator rotor.…”