Analysis of Tooth-Tip Flux Leakage in Surface-Mounted Permanent Magnet Linear Vernier Machines

The permanent magnet linear vernier (PMLV) machine is becoming attractive for low-speed and direct-drive applications. Due to its vernier structure and multipole configuration, the flux leakage especially the tooth-tip flux leakage is severe. In order to analyze its leakage flux, the magnetic equivalent network of the PMLV machine is applied for analytical modeling. During modeling, the fringing effect in the air-gap is taken into consideration. The key for the flux leakage calculation is to calculate the permeances at different tooth positions. Finally, in order to evaluate the proposed analytical model of the PMLV machine, the finite element method is employed for numerical calculation. The comparison between the analytical and numerical results verifies that the proposed analytical modeling approach is valid and accurate.