Page 18: of Maritime Reporter Magazine (June 2022)

The Path to Zero

Permanent Magnets:

May the Force be with You

Forward-thinking owners who want to optimize energy ef ciency and outrun ever-stricter environmental regulations need future-proof propulsion solutions that are versatile and reliable. Direct-drive electric propulsion based on permanent magnet (PM) technology ticks all the boxes, says Jussi Puranen of

Yaskawa Environmental Energy / T e Switch.

am convinced that direct-drive electric propulsion will screws. The system can be used both with ? xed pitch and con- replace conventional diesel-mechanical systems as the trollable pitch propellers, and in the future could also be possi- premium solution for energy-ef? cient ships within 10 ble for podded propulsion. Power capacity suits any size of ves- years. sel. The latest-generation machines can provide up to 12MW to

I Given looming new regulations including EEXI and 15MW on one shaft line, but two in tandem doubles the power.

CII, and Phase 3 of EEDI, many existing ships will need to The same tandem solution on twin shaft lines can give up to be retro? tted to improve performance. Ships with low EEXI scores may struggle commercially as the market becomes more choosey, while poor performance in the CII will also put vessels at a competitive disadvantage. Owners will need to take remedial action.

Leading the pack

Direct-drive electric propulsion based on permanent mag- net technology is, in my view, the premium solution to meet these challenges. The system does not require gearing and is signi? cantly more reliable versus conventional geared instal- lations. Everyone knows replacing a dodgy gearbox on any vessel is a huge task.

The ‘permanent’ in PM means the magnetic ? eld created requires no current to be fed into the rotating unit, making the technology very ef? cient. Rotation speed of the motor is around 100 rpm instead of 1,000 or 1,500 rpm. PM motors are also much simpler in construction than conventional syn- chronous motors. Only minor maintenance such as checking seals and cooling fans is required, prolonging motor life and reducing operating costs.

Integration ? exibility

PM motors have already been successfully applied to direct- drive electric propulsion in ships both with single and twin

Photo courtesy Yaskawa Environmental Energy / The Switch 18 Maritime Reporter & Engineering News • June 2022

MR #6 (18-33).indd 18 6/6/2022 10:02:05 AM