A novel methodology to design permanent magnet synchronous generator for ocean current turbine applications

Permanent Magnet Synchronous Generator (PMSG) is a type of electric generator where external excitation source is not required to produce a magnetic field because of which it suits underwater electricity generation using Ocean Current Turbines (OCT). Due to the slow speed nature of the OCT, mechanical transmission systems such as gear box, belt drives usually being used to fit the torque — speed characteristics of OCTS with the high speed PMSGs. This results in high starting torque in addition to the transmission losses. To avoid these issues, low speed PMSGs are required to be designed for the speed-torque characteristics of the OCT. This paper briefs the novel methodology to design the low speed PMSGs for the OCT applications and in-house fabrication of a low speed PMSG using the same methodology.