Hybrid Circuit Breaker Could Reduce Injuries from Electric Arcs

BATON ROUGE -- An LSU-patented circuit breaker could slash costs for industrial plants

and sharply limit injuries from arc flash, the lightning bolt created when high voltage equipment fails and electricity jumps from one conductor to another.

Arc flash can travel up to six feet and reach temperatures of 35,000 degrees Fahrenheit or about 19,000 degrees Celsius, three times hotter than the surface of the sun. A 2022 article in Electrical Contractor magazine says arc flash results in 7,000 burns and 2,000 hospitalizations each year.

“Direct current (DC) arc flashes can be far more dangerous because the current is constant. The arcs can last longer and release more energy, causing more damage and injuries,” LSU Electrical and Computer Engineering Professor Shahab Mehraeen said. “In alternating current (AC) systems, the current drops to zero at the end of each cycle, which can interrupt the arc. In DC systems, there is no natural break. Our design means no significant arcs result.”

The industry standard is a mechanical switch, whose design hasn’t changed much in decades. When the current rises above a set limit, a spring is triggered, forcing the contacts apart. Mehraeen’s switch can interrupt the current in about 20 milliseconds.

Mehraeen’s hybrid circuit breaker uses a mechanical switch supported by an electronic switch. The breaker creates a “current-zero crossing,” a point where there is no current, and reverses the current, sending some of the energy back from where it came.

His design offers three major advantages.

• It’s faster, breaking the current in less than half the time.
• It’s safer. By interrupting and rerouting the current, the breaker minimizes arc flash. This dramatically cuts the risk of injuries, such as severe burns and eye damage, and limits equipment damage.
• It’s cheaper. The higher the current, the more expensive the circuit breaker. Industrial strength mechanical breakers cost anywhere from $500 to $15,000. The components for Mehraeen’s hybrid circuit breaker are less than $300.

“Dr. Mehraeen’s invention could mean safer, more efficient industrial plants and a more resilient power grid,” said Robert Twilley, LSU vice president of research and economic development. “His discovery exemplifies the university’s Scholarship First Agenda goal of harnessing innovation to better the lives of people in Louisiana and around the world.”

Mehraeen patented his hybrid circuit breaker with the help of LSU’s Office of Innovation & Technology Commercialization (ITC).

The global market for circuit breakers is estimated at between $6 billion and $9 billion. Mehraeen’s device has a number of potential applications, from DC power grids and green technology, such as solar panels and electric vehicle charging stations, to consumer goods like LED lamps and batteries.

However, Mehraeen believes his invention will work best in industrial settings: chemical and petrochemical plants, refineries and factories.

“We are excited to work with Dr. Mehraeen to pursue the potential for this breakthrough technology,” said Mariel Liggin, commercialization officer with LSU’s Office of Innovation & Technology Commercialization.

About LSU’s Office of Innovation & Technology Commercialization

LSU’s Office of Innovation & Technology Commercialization (ITC) protects and commercializes LSU’s intellectual property. The office focuses on transferring early-stage inventions and works into the marketplace for the greater benefit of society. ITC also handles federal invention reporting, which allows LSU to receive hundreds of millions of dollars each year in federally funded research, and processes confidentiality agreements, material transfer agreements and other agreements related to intellectual property.

For licensing inquiries, contact techlicensing@lsu.edu