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

Abstract

The use of a cobalt-iron (VaCoFe) core is investigated as an alternative to silicon-iron (FeSi) in the design of interior permanent magnet synchronous motors (IPMSM). Considering VaCoFe and FeSi cores, a spoke-type IPMSM geometry is optimized for a torque range up to 40 N·m, providing a general comparative analysis between materials. This is done considering the application of a four-motor competition vehicle’s powertrain. A genetic optimization algorithm is coupled to the motor’s electromagnetic and thermal hybrid analytical/finite-element model to provide sufficiently accurate results within a feasible time. VaCoFe allows an estimated increase of up to 64% in torque for the same efficiency level, or up to 5% in efficiency for the same torque. 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 were found for the VaCoFe at 20 N·m. In addition, for the same motor volume, the VaCoFe allows an increase of 51.9% in torque with an increase of 1.1% in efficiency when compared with FeSi.

Recent Developments in Electrical Machine Design for the Electrification of Industrial and Transportation Systems

“…(a) High-temperature superconductors that can be used as tapes for conducting high electric currents, or as bulks, for storing or shielding high magnetic fluxes [20,21]; (b) Cobalt-iron alloys, which allow a higher magnetic flux density [22]; (c) Soft magnetic composites, which allow 3D magnetic flux paths useful for multi-DOF machines [23], and; (d) Nanofluids for cooling, such as aluminum oxides and nitride, further expand electrical machines' cooling capabilities [24].…”

“…Using higher magnetic saturation alloys is another approach that can contribute to increasing the electrical machines' specific power. In [22], the application of cobalt-iron (CoFe) alloys is explored for a PMSM. The authors perform two optimizations of the PMSM, with FeSi and CoFe, for the same machine volume.…”

A New Concept of Direct Oil Cooling System for AFPM Machines, Numerical Analysis and Optimization

“…The state of the art in AFPM machines has been rapidly advancing in recent years, due to the growing demand for high-efficiency electric motors. Overall, the state of the art in AFPM machines is characterized by a continuous push for higher power density, improved efficiency, and lower cost [1]. As the demand for electric motors continues to grow, it is likely that we will see further advancements in AFPM technology in the coming years [2] The air gap flux permanent magnet (AFPM) machine is a promising technology that has gained significant attention in recent years due to its high torque density, compact size, and improved efficiency [3].…”