Alaska SMES: Form and Function for the World’s Largest Magnet
A superconducting magnetic energy storage (SMES) system for utility applications is planned for installation at Anchorage Municipal Light & Power in 2000. The system’s stored energy of 1800 MJ (0.5 MWh) will be delivered at power levels up to 31.5 MVA for spinning reserve, voltage support and electrical network stabilization.
A low aspect ratio solenoidal superconducting magnet will store and deliver energy. The magnet’s maximum operating current is 10.8 kA and the peak field in the winding is 6.1 T. The maximum discharge voltage is 3.375 kV. The magnet will be cooled by pool boiling helium at 4.45 K. A review of our conductor configuration trade analysis and a description of the cryostable, copper stabilized, NbTi conductor is presented. Conductor characteristics including stability are discussed. The pancake winding pack is described. Magnet quench characteristics and protection are presented. Current lead selection criteria are presented and the leads are described. Cryostat design is described and overall magnet system thermal and structural characteristics are presented. Seismic conditions in the Anchorage area are identified and associated structural issues discussed.
Thermal loads are discussed and a description of the refrigeration system is provided. Implications due to the unavailability of LN2 are discussed as well as the required recovery of the cryogenic system from discharge events.
KeywordsCurrent Lead Refrigeration System Vacuum Vessel Cryogenic System Voltage Source Converter
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