InfrastructureA surge protector to end all surge protectors
If an equipment failure, terrorist attack, or lightning strike causes a power surge, also known as a fault current, that fault current can cascade through the grid and knock out every substation and piece of equipment connected to the problem site; DHS’s Resilient Electric Grid project aims to develop a superconductor cable designed to suppress fault currents that can potentially cause permanent equipment damage
On 14 August 2003, more than forty million people were plunged into darkness when electrical service failed in large portions of the Northeastern and Midwestern United States and Ontario, Canada. Though many workplaces ceased functioning without electricity, New York City’s emergency medical services had to deal with a doubling of call volume during the 29-hour blackout, according to a 2006 report in Prehospital and Disaster Medicine.
Cardiac and respiratory complaints increased, likely due to commuters being left without subway transportation or elevators, according to the report. Paramedics responded to a large number of heat-related medical calls because air conditioners could not function. Ambulances struggled to navigate streets that lacked functioning traffic signals and were crowded with commuters walking home.
Communications of the ACM reports that DHS Science and Technology Directorate (S&T) is supporting a technological advance that could reduce the chances of similar blackouts occurring in the future. The Directorate’s Homeland Security Advanced Research Projects Agency (HSARPA) helped fund the development of an electrical cable that could be used to link substations, providing backup sources of electricity in the event part of the grid experiences an outage. The Resilient Electric Grid project will help ensure the nation’s utilities can withstand power surges that cause blackouts.
According to Sarah Mahmood, program manager for HSARPA, electric utilities have hesitated to connect substations in the past. Although one substation can compensate for another’s outage if the two are linked, there is a downside to building an interconnected grid. If an equipment failure, terrorist attack, or lightning strike causes a power surge, also known as a fault current, that fault current can cascade through the grid and knock out every substation and piece of equipment connected to the problem site. Part of the Resilient Electric Grid project is the development of a superconductor cable designed to suppress fault currents that can potentially cause permanent equipment damage. This technology will allow electric companies to link substations without running the risk of fault currents cascading through the electric grid. “This will help [first responders] by keeping that backbone [of the electric grid] up and running,” Mahmood said.
In 2007 HSARPA awarded a contract to American Superconductor Corporation to develop an inherently fault-current limiting high-temperature superconductor cable (IFCL-HTS), also known as Secure Super Grids, which was the first of its kind. A superconductor offers no resistance to electricity flowing through it, thus eliminating power loss incurred with regular wires.