May 8, 2017

Perle Converter team wins $10,000 Clean Energy Prize in Duke Startup Challenge

Nicholas Institute for Environmental Policy Solutions

The annual Duke Startup Challenge, a yearlong competition followed by an accelerator program, is designed to help Duke's entrepreneurship community flourish. In 2016-17, the Duke University Energy Initiative offered the Clean Energy Prize ($10,000) in conjunction with the Startup Challenge, which is hosted by the Duke Innovation & Entrepreneurship Initiative and the Fuqua School of Business.  

The Energy Initiative has awarded the 2016-17 Clean Energy Prize to the Perle Converter team: researcher Dr. Stefan Goetz and graduate student Chris Dougher. Their solution is a technology that can be used with solar panel systems, for battery storage, and in the growing electric vehicle market.

Winning technology converts power more efficiently, reliably, robustly, and economically

Throughout most of the world, the electrical grid delivers power in the form of Alternating Current (AC). However, many applications generate, store, or use Direct Current (DC). The team's new technology uses innovative circuitry design to perform conversion between AC and DC at higher efficiencies than existing technologies, resulting in a more robust performance, higher mean-time between failures (MTBF), and lower costs.

In recent years, some companies have been studying cost-effective, mass-produced low-voltage semiconductors and chip components to do the job of conventional costly high-voltage inverters. These new Modular Multilevel Converters (MMCs) use low-voltage semiconductor switches to take a DC input and create an AC output while effectively connecting the power sources in series. This technology has been used in some applications of pure power conversion, but for nearly a decade, companies have struggled to apply it effectively in battery systems.

The Perle Converter's breakthrough is that it can connect the power sources inside each module dynamically not only in series configurations but in parallel—leading to additional functionality and improved performance. This Modular Multilevel Series and Parallel Converter (MMSPC) can reduce conversion costs by up to 50% while improving efficiency, reliability, and robustness of the overall system.

Dougher and Goetz estimate that current domestic demand for converters exceeds 2.1 million—and is projected to jump to more than 8.3 million by 2019.

Team taps Duke's interdisciplinary strengths in energy

Goetz is an assistant professor in the division of brain stimulation and neurophysiology in the School of Medicine and electrical and computer engineering in the Pratt School of Engineering. His research focuses primarily on power electronics and engineering methods applied to neuroscientific problems. Prior to joining Duke, Goetz worked in industry.

Dougher is pursuing dual degrees: a Master of Environmental Management (MEM) at the Nicholas School of the Environment and a Master of Business Administration (MBA) at the Fuqua School of Business. His MEM concentration area is Energy and Environment. He has a background in manufacturing and operations with PPG Industries and was a Technology-to-Market Summer Scholar at ARPA-E last year.

The Perle Converter originated in Goetz's work on high-performance electronics enabling accurate pulse control in noninvasive magnetic brain stimulation. The resulting techniques are so precise that doctors can control activation dynamics of patients' neurons, including those in the motor cortex involved in voluntary muscular movements.

The application of new conversion methods to solar systems, electric vehicles, and other industries was kickstarted by an Energy Research Seed Fund grant from the Duke University Energy Initiative, followed by a $500,000 National Science Foundation grant supporting Duke researchers' collaboration with those at the Freedom Systems Center in Raleigh.  

Goetz says that the widespread interest in energy across the university—and a culture that encourages interdisciplinary collaboration via units like the Energy Initiative and the Innovation and Entrepreneurship Initiative—makes Duke a great place to innovate.  

"It's very intentional, how Duke brings people together across disciplines to work on important problems like energy," notes Goetz. "That strategy helps make Duke researchers' work stronger and more actionable. Chris has been an invaluable partner. He also understands well how to maximize the impact of the design through a farsighted strategy and a strong business plan."  

Dougher adds, "I have been very lucky to work with Dr. Goetz and his team on such an exciting technology. He has been extremely supportive of the commercialization efforts underway. It is also great to work with the Energy Initiative again on helping drive entrepreneurial efforts at Duke."

When presenting the Clean Energy Prize to Dougher and Goetz, Energy Initiative interim director Brian Murray remarked, "The judges were very impressed by what Chris and Stefan are up to. But we were also impressed by how difficult it was to select a winner for this prize. Duke students and faculty are exploring promising solutions for some of our world's most pressing energy challenges, and we wish we could invest in multiple teams."    

The Perle Converter Team remains a contender for other recognition in the 18th annual Duke Startup Challenge.   

For more information, contact Braden Welborn