In 2003, much of the northeast United States and parts of Canada experienced massive blackouts, leaving 50 million people with no power and costing billions of dollars in repairs. More recently, Hurricane Sandy on the East Coast left over 8.5 million people without power.
Lightning in contact with power lines is a common cause of power outages. (Image via Huntington Heating)
Luckily, advancements are being made to help prevent, or at least lessen the effects of power outages.
Building on existing technology, researchers from the University of Arkansas have developed equipment that regulates the amount of excess current that moves through the power grid when a surge occurs. The device springs from the invention of the fault current limiter, which, as its name implies, limits the amount of abnormal current when faults like short circuits occur.
Over the past five years, Alan Mantooth, professor and executive director of the National Center for Reliable Electric Power Transmission at the University of Arkansas, along with his team, developed the first kind of fault current limiter that uses silicon-carbide semiconductor technology.
“The significance of this material cannot be overestimated. It is much more durable and responds so much faster than materials currently used in systems on the U.S. power grid,” said Mantooth.
What causes an outage, anyway?
The more common types of surges are typically caused by an unintended event such as lightning striking or a tree coming in contact with power lines. The result is an out-of-control current, creating a short-circuit. At this point, electricity is drawn from power sources within the grid, but if these sources do not have the extra power to give, smaller, rolling blackouts will occur.
So what does a silicon-carbide fault current limiter do?
The team describes a fault current limiter as a “giant surge protector,” absorbing the excess current and sending only the necessary amount down the line. If the fault has caused more permanent damage to the power lines, it will act as a circuit breaker to prevent further damage.
By working with the stronger and faster material, silicon carbide, University of Arkansas researchers created a limiter with high-speed switching devices that quickly absorb the energy. Working with silicon carbide also means that it can function at higher temperatures and will reduce the amount of equipment needed on a power grid.
Future impact
Such devices could come in handy in facilities such as hospitals, where electricity is vital, but also in neighborhoods where just one limiter could regulate current and save many homes from experiencing a power loss.
Mantooth believes this development and even just current limiters in general are an important part of the development of a “smart” grid.
“This device really can mean the difference between 25,000 customers or 5 million customers being affected,” said Mantooth.
German researchers are working on transforming the energy supply system.
(Image via Fraunhofer Institute for Wind and Energy System Technology: fotalia)
Avoiding blackouts is a goal around the world. Currently, South African power utility company Eskom revealed it was ready to initiate rolling blackouts this winter in some parts of the grid in order to prevent a complete system collapse.
Even the Fraunhofer Institute for Wind and Energy System Technology in Kassel, Germany, is delving into the topic of blackout prevention, suggesting that joining renewable energies such as solar, wind, and biogas plants can help avoid electric shortages.
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