New Superconducting Magnet Will Lead to Next Generation of Wind Turbine Generators

AML Superconductivity and Magnetics, in conjunction with the U.S. Department of Energy's (DOE’s) Argonne National Laboratory, recently announced that their superconducting magnet system passed a landmark reliability test, demonstrating its potential suitability for wide-scale commercial applications. This new superconducting magnet will help establish a new generation of turbine generators that are roughly half the size and weight of those currently in operation.

In 2012, DOE funded AML's design for a superconducting generator for large-scale, high-efficiency offshore wind turbines. AML worked with its partners, Emerson Electric Corporation, Creare Inc., DNV USA, and DOE’s Argonne National Laboratory to develop the design for a 10-megawatt (MW) direct-drive fully superconducting generator. According to AML’s Vice President of Development, Vernon Prince, the design has been thoroughly vetted and validated by DOE and is ready for a full-scale demonstration project and volume manufacturing.

Key potential advantages of the AML direct-drive generator include improved scalability, reduced weight, and coils that are free of rare-earth materials. AML's design does not require a gearbox, which may lead to improved reliability and reduced maintenance costs. Although this may also be true for contemporary, gearbox-free direct-drive generator designs, the AML generator makes a magnetic field using superconducting windings that are more powerful and compact than copper-based alternatives. They are also constructed of more readily available and lower-cost materials than permanent-magnet-based generators, which are sensitive to cost fluctuations in the volatile rare-earth magnet market. In addition, AML calculates that its generator will weigh up to 50% less than a comparable permanent-magnet rare-earth generator with a 10-MW power rating. A lower generator mass has major system benefits, including a lighter—and thus less expensive—tower, and reduced installation costs through the use of smaller cranes and offshore vessels.