Nothing energizes Dr. Alex Huang quite like a power outage. So a rolling blackout across Texas in April and a summer filled with expected overloads on the nation’s electricity grid have the director of Semiconductor Power Electronics Center (SPEC) hopping. Located on Centennial Campus, the center is a leader in developing solid-state power electronics systems to control the transmission and distribution of electricity.

Power semiconductors are commonplace in computers and cell phones, helping conserve battery life while switching on and off rapidly as they move from one function to the next. Huang says the same concept can be super-sized to handle the millions of watts of electricity that move across power transmission lines and redistribute them as needed to avoid blackouts. “A solid-state controller would stabilize voltage,” he says, “and transform the power grid from a passive system to an actively controlled operation.”

Current high-voltage controllers turn on and off in fractions of a second, but Huang says that’s still too slow for a power grid that often operates close to capacity. In the time it takes a controller to switch on or off, too much or too little electricity to meet demand may be moving through the grid, he says. Using power semiconductors with optical control, SPEC is developing controllers that switch on and off in microseconds, providing almost continuous voltage regulation and the ability to redirect power quickly to needed areas. “We should really call it digital energy—that’s a much sexier name,” Huang says with a laugh. “We’re basically chopping electricity into pulses so it can be synthesized back together later.”

A soft-spoken, quick-witted native of China, Huang was lured to NC State two years ago from Virginia Tech to open SPEC, the only university-based research operation in the U.S. dedicated to utility electronics. Its Centennial Campus location provides a close working relationship with ABB, an international leader in energy engineering with a large research facility and 250 employees on campus. SPEC also has demonstration projects with federal utilities like the Tennessee Valley Authority and Bonneville Power Administration to regulate fluctuations in power demand and supply.

Huang says more work is needed to move the solid-state controllers into the commercial market. Researchers are testing power converters with a scrub brush-like array of slender pipes attached, for example, to replace a system of water pumps and hoses used to cool the semiconductors. The “heat pipes” lower the risk of system breakdowns by eliminating several mechanical parts. “A semiconductor is still not as reliable as a piece of copper,” he says. “We’re working to make the technology smaller, less expensive, and more reliable.”


For more information, please visit
www.ece.ncsu.edu/spec