Researcher receives grant to improve electrical grid

Gabriela Hug is working to make the U.S. electrical grid more efficient. (credit: Jonathan Carreon/Contributing Editor) Gabriela Hug is working to make the U.S. electrical grid more efficient. (credit: Jonathan Carreon/Contributing Editor)

You use electricity all the time — when you charge your phone, when you turn on the lights, when you cook. But where does this electricity come from? How is it distributed to you?

The answer to these questions is an electrical grid that spans the entire U.S. and delivers electricity from suppliers to consumers through a three-part system: power stations produce electricity, transmission lines carry electricity from these stations to demand centers, and transformers that reduce voltage so the transmission lines can carry power to their final destinations.

Unfortunately, the current state of the electrical grid is inefficient. Electrical and computer engineering assistant professor Gabriela Hug, who is also affiliated with the engineering and public policy department, is working to overcome this obstacle. She was recently awarded a five-year $400,000 grant from the National Science Foundation (NSF) to fund her groundbreaking research on improving our power grid’s efficiency.

The way the grid is designed right now, electrical current flows through transmission lines following Kirchhoff’s laws — a set of circuit rules stating that the sum of all currents flowing into one node is zero, and that the sum of the voltage gains and drops in any circuit loop is also zero. “You can’t tell an electron which way to flow,” Hug joked. However, there are certain devices such as the Flexible Alternating Current Transmission System (FACTS) that can be used to influence parameters on a line.

“For example, if you have two of the same resistors in parallel, half of the current will flow through one line and the other half will flow through the second line,” Hug said. “But if you influence the resistance in one of the wires, you can push part of the current into the other line.” Essentially, these devices will allow us to control the flow of current through the electric power grid. But why is flexibility in the power grid so important?

With increased efforts for renewable energy, sources of power generation have become much more diverse. Coal power plants — which produce predictable and stable outputs of power each day — were the power sources of the past. Now scientists must take into account the fluctuations that are inherent to other forms of power, such as wind or solar power.

Hug’s research focuses on how to optimize the use of devices such as FACTS in the power grid. “What values should they be set to? Should they be coordinated from a centralized control center or locally?” Hug asked.

Another method to increase the power grid’s flexibility is determining how to optimally integrate large-scale storage. “Right now we don’t have a lot of storage in the power system,” Hug said. “Whenever I flip a switch or use more power, the generator needs to change its output depending on what I’m doing. Storage allows you to use some of the energy you have in your storage to supply your load.” The problem is figuring out when you should charge the storage and when you should use the energy from the storage.

The students who work with Hug conduct all their experiments computationally, as the real electric power grid is too big to test ideas on. Since the improvement of the power grid is a task that involves both scientific solutions and effective policy, Hug works with both engineering and policy students, with the policy group using mathematical models of the system to see the social and economic outcomes of applying the technical solutions provided by the engineering group.

Hug plans to use the NSF grant to further her research. As efforts to harness renewable energy improve, so too will our electric power grid system