5,000 hp superconducting motor passes tests

Researchers in the US have completed load tests on the world`s largest motor to have rotor windings formed from high temperature superconducting (HTS) wires. The successful testing of the 5,000hp (3.73MW) prototype motor could pave the way for commercialisation of HTS motors, one-fifth the size of conventional motors, by 2004.

During the tests, the motor (above) was subjected to a peak load of 7,000hp (5.2MW) and operated at a full-load efficiency, including its cryogenic refrigeration system, of 97.2%. The researchers at the American Superconductor Corporation (ASC) have identified improvements to the design and manufacturing that they think could raise efficiencies to 97.7%.

High-power HTS motors could be much smaller, lighter, more efficient and cheaper to produce than conventional machines. "Motors of this type will revolutionise markets such as marine propulsion," predicts ASC chief executive Greg Yurek.

The availability of the HTS motors could accelerate the trend towards the electrical propulsion of ships. Sales of marine motors are forecast to grow from $400m at present to $2-4bn within ten years.

ASC is now planning to design and build a higher-torque, lower-speed HTS motor, as a prototype that could be tested on a ship.