Electricity solutions company American Superconductor Corp and the Corporate Technology unit of Siemens AG have formed a strategic alliance to develop and explore the commercialization aspects of high temperature superconductor (HTS) fault current limiters by building and testing FCL components based on AMSC's second generation (2G) HTS wire. Fault current limiters (FCLs) are expected to serve as high-voltage surge protectors for power grids.
Prior to establishing this alliance, Siemens and AMSC, in close contact with electric utilities across Europe, Canada, and the U.S., defined specific customer needs that meet their performance and economic requirements for today's complex power networks. Based on this input, the companies jointly crafted a roadmap to demonstrate FCLs based on AMSC's 2G HTS wire and Siemens' fault current limiter design.
Siemens and AMSC have been involved in developing fault current limiters since the beginning of the 1990s, utilizing different configurations of available HTS materials. This alliance allows both companies to capitalize on their earlier work and proprietary technologies to conceive of practical FCLs that are based on the advanced 2G HTS wire expected to become available in commercial quantities over the next couple of years. Under the terms of the agreement, Siemens will develop performance requirements for its FCL design and AMSC will tailor its standard 2G HTS wire to meet those specifications. The first deliveries of 2G HTS wire to Siemens are expected to be made from AMSC's pre-pilot manufacturing line in 2005.
FCL Applications
When a short circuit occurs in an electrical transmission or distribution system, an electrical generator feeding power into that system responds by creating a surge of current throughout the grid. Unless circuit breakers open up to stop this surge (technically, a "fault current"), it can damage expensive equipment, such as transformers, located in electrical substations and elsewhere on the grid.
As grids around the world grow, the current level in the surges grows, increasing the need for utilities to upgrade breakers or consider other solutions, such as FCLs, that protect the grid. Worldwide, the resulting cost to electric utilities amounts to hundreds of millions of dollars each year, according to the U.S. Dept of Energy. A fault current limiter (also called a fault current controller) uses superconductors to instantaneously limit electrical surges -- or reduce them to more normal levels -- before they reach a circuit breaker. (Fault current limiters based on conventional electrical conductors do not exist. Only superconductors possess the unique physical properties that allow them to react instantaneously to current changes, passing electricity along at normal levels while dampening the surges.)
To learn more about FCLs please see www.amsuper.com/products/htsWire/FaultCurrentLimiters.cfm and www.electricity.doe.gov/.
To learn more about Siemens' activities on superconducting components and equipment please see www.industry.siemens.com/marine/EN/products_systems/innovations.htm.
To learn more about 2G HTS wire and AMSC's plans for scaling up production of 2G HTS wire, please see www.amsuper.com/products/htsWire/2GWireTechnology.cfm.
