Abstract
The partitioned stator switched-flux permanent magnet (PM) (SFPM) (PS-SFPM) machine is a novel stator-PM machine in which PMs and armature windings are separately placed in two different stators. Compared with the conventional SFPM machine with a single stator in which both PMs and armature windings are located, the PS-SFPM machine can generate higher torque density due to the utilization of the machine's inner space. In this paper, the magnetic gearing effect in the PS-SFPM machine is investigated in terms of air-gap field harmonics based on a simple magnetomotive force (MMF)-permeance model. It is found that the PS-SFPM machine is one type of magnetically-geared machine, in which the modulations of rotor iron pieces to the open-circuit PM and armature reaction fields are similar to those found in the magnetic gear and the conventional magnetically geared machine. The pole-pair numbers and rotating speeds of the air-gap field harmonics obtained by the MMF-permeance model are verified by finite element (FE) analysis. More than 93% of the average electromagnetic torque is contributed by the main air-gap field harmonics having pole-pair numbers (2i - 1)p PM and Nr,pm, (2i-1)pPM( i = 1,2,3) in a PS-SFPM machine with pPM-pole-pair PMs and Nr-rotor-pole. A prototype machine is fabricated and tested to verify the FE analysis.
| Original language | English |
|---|---|
| Article number | 7511752 |
| Pages (from-to) | 1239-1249 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Energy Conversion |
| Volume | 31 |
| Issue number | 4 |
| Early online date | 12 Jul 2016 |
| DOIs | |
| Publication status | Published - 1 Dec 2016 |
Keywords
- Magnetic gear
- magnetic gearing effect
- magnetically-geared machine
- modulation
- partitioned stator
- permanent magnet
- switched flux
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering