Robust Design of Permanent Magnet Motors for Electric Traction Applications

This paper presents a methodology enabling robust design of permanent magnet motors constituting a favored choice in electric traction applications, particularly promising in high speed ranges. Appropriate permanent magnet grade and configuration selection ensuring satisfaction of standard design criteria such as high efficiency and high power density over a wide range of operating conditions are considered in conjunction with fault risk avoidance offering enhanced robustness and drive viability. Higher harmonic phenomena introduce increased stray losses in high speeds such as eddy current losses in surface mounted permanent magnets and are taken into consideration through an appropriate coupled field and circuit approach. The proposed modeling techniques are validated by measurements in prototype linear machine experimental set-up.