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February 1997



Power electronics group to build converter for superconducting magnetic energy storage

In the VPEC laboratories, Kunrong Wang (G) works on a design of a power conditioning system to be used for Superconducting Magnetic Energy Storage (SMES).

The Virginia Power Electronics Center (VPEC) has received a contract from Westinghouse Inc. and the Office of Naval Research to develop a system that will convert electrical energy for magnetic storage by utilities. Under the three-year $700,000 contract, VPEC will develop a prototype power conditioning system for Superconducting Magnetic Energy Storage (SMES), which is a state-of-the-art method for storing electrical energy.

A SMES unit consists of superconducting wire wound into a huge coil, which is cooled with liquid helium to minus 458 degrees Fahrenheit so that the flow of electricity meets no resistance. Direct-current (DC) electricity is fed into the coil, creating a magnetic field that can store the energy indefinitely.

The power conditioning system being developed by VPEC will convert excess AC electricity from utility lines to DC electricity that can be stored in SMES units. When the stored energy is needed, the power conditioning system converts the DC electricity into AC for utility line use.

Utilities can store excess energy in SMES units during the night and retrieve energy for use during peak-demand periods of the day. The storage-retrieval process is expected to be more than 95 percent efficient, which will enable utilities to realize significant cost-saving benefits.

The power conditioning system project is led by Professors Fred Lee and Dushan Boroyevich.


The Bradley Department of Electrical Engineering
Virginia Tech

Last Updated, May 5, 1997
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