Roald to use NSF CAREER Award to optimize risk mitigation in electric distribution grids

// Electrical & Computer Engineering

Assistant Professor Line Roald

The resilience of the power grid has been in the news a lot in recent years: Transmission equipment, for example, sparked some of the largest fires in California history in 2018, leading to rolling blackouts, and the February 2021 cold snap in Texas shut off power to millions for days on end.

While those incidents were high-profile, they repeat across the nation on a smaller scale hundreds of times per year. In fact, it’s estimated that severe weather alone causes about $44 billion in power outage costs annually in the United States. As climate change alters weather patterns, it’s likely weather-related outages will increase. That’s why Line Roald, an assistant professor of electrical and computer engineering at the University of Wisconsin-Madison, will study ways to mitigate these problems through a research project funded by a National Science Foundation CAREER Award.

Roald will use the five-year, $500,000 grant to develop risk assessment methods to quantify short-term operational risk to electric distribution grids.

Managers of transmission lines (the large electric lines that carry energy from power generating sources to transmission stations) have a long history of proactively mitigating risk to make sure there is no disruption in the energy supply. However, because of the different structure and instrumentation of electric distribution grids (the lines that bring power directly into homes and businesses), local utilities or co-ops that operate these grids usually manage risk differently.

Typically, utilities respond to problems and outages as they arise and conduct annual risk assessments to identify issues after-the-fact. “In the past, there was nothing wrong with this reactive approach,” says Roald. “But the current increases in renewable energy, massive investments in distribution automation and increased frequency of severe weather make a more proactive approach both technically viable and necessary.”

In her project, Roald will use data to develop new methods to help utilities optimize a new generation of devices that can control power flows using technologies such as remote switching. That will allow them to turn off or reroute power to mitigate risks—for instance, shutting off power to lines with overhanging vegetation on extremely windy days. Her second thrust is developing mathematical models and solution methods to mitigate risks associated with different failure scenarios, like wildfire risks or severe weather.

“I’m essentially trying to develop a framework that allows utilities to assess risks and use that knowledge to come up with better solutions across a number of future scenarios,” Roald says.

Eventually, she hopes utilities will be able to adopt her framework through open-source models they can integrate into systems to mitigate risks. That’s why she’s partnering with local Madison-area utility MG&E and the National Rural Electricity Coop Association, which represents more than 900 not-for-profit utilities. Their experience and data will help keep her modeling and assumptions grounded in reality, increasing their usefulness.

The CAREER project also has a significant educational component. Roald plans to use the open-source language Julia to develop educational materials for undergraduates that will help them improve their analysis and programming skills. She also hopes to develop a targeted program for teaching assistants in introductory electrical engineering classes that will serve to promote the retention of historically underrepresented students in STEM.

“I want to train a new generation of researchers in what it means to be inclusive and promote equity and opportunity for all,” she says.

That is in line with Roald’s overall research interest, which is improving the world as best as she can through her work. “My long-term career goal and why am I here in first place is because I really want to contribute to maintaining an electric grid that can enable climate change mitigation,” she says. “We’re really at a crossroads where on the one hand we’re pushing the grid into a renewable future but we’re also asking more than ever from the grid. How we put things together in the future is going to be interesting; I’m excited and optimistic on how we get there.”

Author: Jason Daley