Drives and Controls Magazine
‘Game-changing’ electric motors could power aircraft
Published:  14 March, 2017

An Australian company is developing a “game-changing” series of high-power-density electric motors that could be used to propel aircraft, and for other applications needing small, powerful motors. Queensland-based magniX has received an A$2.5m (US $1.9m) grant from the Australian Government as part of a A$12m (US $9.1m) collaborative project aimed at developing motors with power densities of more than 5kW/kg – more than twice as high as the best conventional motors. Magnix believes that it could eventually achieve power densities of 25kW/kg­ – three times higher than modern aircraft engines.

MagniX is working on various technologies including permanent magnet and superconducting motors and generators, all based on “precision placement of the magnetic field”. The aim is to maximise the field strength where it is useful and to minimise it where it is not, thus boosting power densities. The company is about to start testing a 5kg prototype motor.

The “magniflux” technology reduces the amount of steel in the rotor, and thus its weight, resulting in fast transient responses and the ability either to reverse direction quickly or to switch rapidly from motoring to generating.

The three-year project – which also involves the University of Queensland and an aeronautical engineering specialist, Ferra Engineering – aims to optimise the design, thermal management and materials needed for the high-power-density motors. Further funding will be needed to commercialise the technology.

“Currently the aircraft industry lacks an electric motor with the required power density to replace fossil-fuel motors,” says magniX’s managing director, Dr Jason Chaffey. “Lightweight and power-dense motors are needed to make this a reality and magnix has unique capabilities and proven intellectual property in this area. The government funding will allow us to accelerate our ambitious commercial program.”

Ferra Engineering’s managing director, Mark Arthur, describes magniX’s technology as “game-changing”, and predicts that it will “revolutionise the aircraft industry”.

Magnix claims that its motor technologies will achieve much higher power densities than conventional technologies

MagniX is initially offering two commercial versions of its motors with lower power densities. One, weighing 210kg, delivers 150kW and 1,500Nm continuous (200kW and 2,500Nm peak), with an efficiency of more than 97%. The 480mm-diameter and 450mm-long motor has an operating speed of 900–1,000 rpm (with a maximum of more than 2,700 rpm). The other version, aimed at high-speed applications around 4,000 rpm, weighs 220kg and can deliver 200kW and 485Nm, with an efficiency above 96%.

As well as the motor project, magniX has attracted a A$125,000 (US $95,000) grant from the Queensland Government to help it commercialise a high-efficiency superconducting generator which will produce high currents at low voltages. The generator, which could operate at efficiencies of up to 99%, is aimed at energy-intensive applications such as smelting, electrolysis and manufacturing hydrogen. MagniX is working with a US company, Vodik Labs, which has developed an advanced electrolysis technology for producing hydrogen. The grant will allow magnix to verify the performance of its generator with this technology and could lead to its commercialisation within 18 months.

Another magniX technology is a high-torque magnetic coupling which is said to weigh about half as much as rival technologies. The 172mm-diameter coupling weighing 10kg can operate at speeds of up to 5,000 rpm and transmit up to 500Nm of torque in or out of a sealed environment without needing a mechanical connection. It can be retrofitted to existing applications that use magnetic or non-magnetic couplings.

MagniX is a subsidiary of Singapore-based Heron Energy.