The SSD: a commercial application of magnetic energy storage

A magnetic energy storage system, SSD, has been developed to provide power to industrial electric loads subjected to short-term voltage disturbances. An overview of the SSD system as presently installed at customer sites, including magnet, cryostat, refrigeration, and power conditioning equipment, is provided. Electric power interruptions are unpredictable in time but are typically of short duration. The SSD system provides rapid response backup power by means of a superconducting magnet connected to the load through a current-to-voltage converter and a DC-to-AC inverter. Power flows from the magnet to the load when the line voltage drops below a preset value. The magnet was designed with terminal characteristics matched to the inverter DC voltage, connected load, and required carryover time. Cryogen inventory is maintained through use of a Collins cycle liquefier. All system components were designed for long-term unattended operation and can be mounted in a semitrailer. Remote monitoring provides information on system performance and status.<>