Efficiency improvement at high-speed operation using large air-gap configuration for PMSM

Vacuum cleaner motors need to be capable of providing high power and high efficiency during high-speed (e.g. 50,000 r/min) operations. Because of this, interior permanent magnet synchronous motors (IPMSM), while highly efficient under general operating conditions, are not normally considered suitable for use in vacuum cleaners because of their tendency to suffer from severe iron loss during high speed operations. These losses have a severe negative impact on motor efficiency. In this research, we examine efforts to reduce iron loss during high-speed IPMSM operations. It is expected that the iron loss of slotless IPMSM operating at high speeds can be greatly decreased because there are no teeth in the area where the magnetic flux density is high. Performance comparisons between slotless IPMSM and conventional IPMSM (which utilize distributed windings) are then performed.