Electrical machines

Comparative sizes of HTS and conventional motors

Superconducting electrical machines using the latest high-temperature (HTS) materials provide the promise of high power levels at a fraction of the volume and weight of existing electrical machines. They offer significant potential for propulsion systems used in transportation applications (eg marine, aerospace, rail) because of the large reduction in the machine size and weight leading in fuel savings and lower emissions. A US company, for example, was recently awarded a $65M contract to develop a 35MW prototype superconducting propulsion motor to undergo evaluation in the latest US navy destroyer. In aerospace NASA have conducted several recent studies into future aircraft propulsion systems to meet the ever-increasing strict legislation on emissions and have concluded that superconducting electric propulsion offers the only viable option, provided significant weight reductions can be found.

Superconducting laboratory test coil using MgB2 wire

Magnesium Diboride (MgB2) conductors are one of the most recently discovered (2001) HTS materials.  Although MgB2 conductors have a lower critical temperature (39K as opposed to about 90K for BSCCO and YBCO), they can be manufactured at low cost in lengths of more than 1km.  Importantly, MgB2 can be supplied in round wire form and can be successfully wound into coils of varying diameters. 

The main objective of this research area is to explore the use of MgB2 wire in the design and prototyping of superconducting machines with the aim of significantly increasing the torque densities beyond the current levels achieved with copper conductors.

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