This paper investigates a non-magnetic improvement technique that enhances power density while also reducing harmonic iron losses in interior permanent magnet synchronous motors (IPMSMs). Topology optimization is employed to explore the optimum placements and shapes of the non-magnetic improvement parts, achieving up to a 24.3% reduction in iron loss by suppressing harmonics in the air-gap flux density without compromising power density. This result demonstrates a significant improvement compared to conventional non-magnetic improvement.
Naruse et al. (Sun,) studied this question.