Electromagnetic Design of a Wave Energy Converter Magnetic Gear with a Torque Density Above 300Nm/L

Wave energy converters generate electricity from the motion of the ocean’s waves. To make wave energy converters cost effective they need to be designed to be highly reliable and low maintenance. The wave energy converter must be capable of efficiently converting the very high torques and low-speed motions created by the waves into higher speeds and lower torque that can be more suitably used for power generation. This paper presents the electromagnetic design of a coaxial magnetic gear (MG) for use in a wave energy converter that can operate with a torque density ≥ 300 Nm/L. A coaxial magnetic gear creates torque-speed change without any physical contact and therefore does not require gear lubrication and will never suffer from tooth wear. A numerical based coaxial magnetic gear sizing analysis is presented. The presented MG design is shown to be capable of breaking the ≥ 300 Nm/L torque density barrier and therefore its performance is competitive with equivalent mechanical gear designs.