Design, Construction, and Analysis of a Large-Scale Inner Stator Radial Flux Magnetically Geared Generator for Wave Energy Conversion Academic Article uri icon


  • 1972-2012 IEEE. A magnetically geared machine (MGM) integrates a magnetic gear with a low-torque, high-speed electric machine to create a single compact high-torque, low-speed device with the size advantages of a mechanically geared system and the reliability of a direct drive machine. This work investigates the use of MGMs for wave energy conversion through the development of a large-scale magnetically decoupled inner stator radial flux magnetically geared generator rated for 10 kW at an input speed of 30 r/min. Critical design trends are illustrated using parametric two-dimensional and three-dimensional finite element simulation results. Information is also provided about the prototype's mechanical structure and key magneto-mechanical design considerations, including the impact of modulator bridges and the extent of axially escaping leakage flux. The prototype's experimental stall torque of 3870 Nm represents a 99.1% match with the simulated stall torque and corresponds to volumetric and gravimetric torque densities of 82.8 kNm/m3 and 14.5 Nm/kg, respectively. Additionally, the prototype achieves an experimental efficiency of approximately 90% for operation near rated torque.

published proceedings


author list (cited authors)

  • Johnson, M., Gardner, M. C., Toliyat, H. A., Englebretson, S., Ouyang, W., & Tschida, C.

citation count

  • 59

complete list of authors

  • Johnson, Matthew||Gardner, Matthew C||Toliyat, Hamid A||Englebretson, Steven||Ouyang, Wen||Tschida, Colin

publication date

  • July 2018