In a collaborative project initiated at the start of 2016, Magnomatics is working with Rolls-Royce Marine and high-voltage induction motor specialist ATB Laurence Scott to develop PDD for marine applications. The 27-month undertaking has a budget of £1.7m (US$2.2m), to which funding agency Innovate UK is contributing £926,000 (US$1.2m), and is focused on the design, manufacture and testing of a 2.5MW magnetically geared propulsion motor (MGPM) using PDD.
It is estimated that use of the machine in propulsion could increase overall vessel energy efficiency by up to 10%, and offer benefits in maintenance, system robustness and operational flexibility, with suitability for both newbuilds and retrofits.
Magnomatics’ patented PDD delivers a continuous torque density up to eight times that of equivalently cooled PM machines while maintaining high efficiency. It combines a magnetic gear with a standard, wound stator. The outer rings of magnets are fixed to the internal bore of the stator, and the magnetic fields generated by the windings drive the internal rotor. The torque produced by the rotor is geared up in the magnetic gear and transmitted out via the central steel pole, resulting in a compact, highly torque-dense machine.