Electron Energy Corp., a leading U.S. producer of rare earth magnets, has been awarded a $750,000 Small Business Technology Transfer Research (STTR) contract by the U.S. Department of Energy Office of Science, Argonne, IL. The Phase II research contract, which runs from August 2008 through August 2009, is for the development of high-performance magnets and magnet technologies for advanced motors used in hybrid-electric vehicles (HEVs). The research will center on innovating a new class of permanent magnets with high magnetic performance, high resistivity, superior thermal stability, and low cost. EEC successfully completed Phase I research in July 2008.
Dr. Jinfang Liu, an internationally recognized expert on rare earth magnet materials and EEC Vice President of Technology and Engineering, will serve as the principal investigator and director of the research project. “Our goal is to design and develop nanocomposite magnets that can reduce eddy-current losses and withstand high temperatures to improve the performance of electric motors for plug-in hybrid cars as well as conventional motors and generator applications,” he said. EEC will collaborate on the research and receive support from the University of Delaware under the leadership of Dr. George Hadjipanayis, the Richard B. Murrey Professor of Physics and Chair of the Department of Physics & Astronomy.
Said EEC President Michael Walmer: “Our research will be critical for the development of plug-in hybrid motors that are more efficient, affordable, and pollution-free. We are pleased to work with the DOE and are confident that the technologies we develop will help decrease U.S. dependence on foreign oil. Ultimately, this program aims to improve performance and significantly reduce the cost of vehicles powered by forms of energy other than those derived from fossil fuel.”
Liu said eddy-current loss is a major consideration in some motor designs. To reduce such loss caused by permanent magnets, designers typically use segmented magnets rather than single-piece ones, which reduces the loss but increases manufacturing cost.
Key components of Phase II research include:
• Improving the magnetic performance of high-temperature magnets by compositional and process-related modifications, as well as developing new hybrid magnets
• Reducing eddy-current losses by increasing the electrical resistivity in new composite magnets that contain dielectric constituents
• Decreasing costs by using less expensive raw materials and lower-cost processes.
Peter Dent, EEC Vice President of Business Development, said EEC proposes to develop a new class of SmCo permanent magnets with an electrical resistivity five to 10 times higher than those of commercially available magnets and superior performance. The high-resistivity magnets, which are able to operate at temperatures above 200°C (390°F), will significantly reduce eddy-current losses and keep the cost for motor/generator systems low.
EEC says it is the only company in the world to produce ultrahigh-temperature SmCo magnets capable of operating in the 350° to 550°C (660° to 1020°F) range and has broad U.S. patent protection for this technology. Competitive magnet technologies have energy products several times lower than EEC high-temperature magnets.
“Motor and generator technologies are quite mature, and progress has been incremental overall,” said Dent when asked by AEI about the degree to which materials development can pave the way to improvement in magnet performance. “Recently, gains in motor efficiency have been obtained from better electronic controls and matching of the electronics to the motors/generators. However, better magnetic material would help produce more dramatic improvements in the efficiency of the motors and generators. New magnetic materials are a key driver for reduced cost and improved performance and efficiency of motors and generators. This specific research program could reduce the number or need for segmenting magnets to reduce eddy-current losses.”
Eddy-current losses in permanent magnets are often just accepted, Dent continued. “New materials under development would significantly increase the electrical resistivity without sacrificing magnetic performance. New high-resistivity magnets would lead to low eddy-current losses and high motor/generator efficiency. Higher-energy product materials improve the energy density or power per unit volume. This leads to a reduction in size and weight of motors and generators.”