Sustain Our Earth

A high-power circuit breaker makes it possible to create highly efficient DC power grids.

"ABB's circuit breaker changes that. Within five milliseconds it can stop the flow of a huge amount of power—equal to the entire output of a nuclear power plant, ABB says. The breakers could be used to nearly instantaneously reroute power in a DC grid around a problem, allowing the grid to keep functioning. “Ordinarily, if something goes wrong anywhere, all the power goes off,” says Claes Rytoft, ABB’s chief technology officer. “The breaker can cut out the faulty line and keep the rest healthy.”

Researchers have been trying to develop high-voltage DC circuit breakers for a century (see “Edison’s Revenge: The Rise of DC Power”). Mechanical switches alone didn't work—they shut off power too slowly. Power electronics made of transistors that can switch on and off large amounts of power offered a possible solution, but they proved far too inefficient. ABB's solution combines power electronics with a mechanical switch to create a hybrid system that's both fast and efficient. The new circuit breaker could also be far less expensive than systems that use only transistors.

http://goo.gl/koDHZ