Professor partners with U.S. Navy, researches all-electric ship

Dr. Annette von Jouanne partnered with the U.S. Navy on the development of electric ships. Photo Courtesy of Baylor University

By Audrey Patterson | Reporter

Dr. Annette von Jouanne, professor of electrical and computer engineering, partnered with the U.S. Navy on the development of electric ships and how sustainable energy relates to transportation.

Von Jouanne said that her life is driven by her Christian faith and that she sees energy as a means of helping people, especially in a sustainable way that provides for our current needs without compromising the needs of future generations.

“As we see in Genesis 2:15, we’re called to be a good steward, and God has provided copious amounts of energy in the Earth; He calls us to activate that energy in a responsible way and use it for man’s good and God’s glory,” von Jouanne said. “That’s what sustainable energy is really looking at, and sustainable transportation falls along those lines. How can we not only generate power very efficiently for utilization, but also for transportation? How can we generate and utilize that energy efficiently?”

Von Jouanne said her research group at Oregon State attracted the attention of the U.S. Navy due to its high power lab, and her continuing work here at Baylor led to further contracts, including a collaboration with the Naval Postgraduate School in 2021.

“Overall, what we are helping the Navy do is to advance their motor drive technology,” von Jouanne said. “When you think of the fact that motors consume about 50% of the electric energy that’s generated in the U.S. — and that’s in industrial applications, commercial and home applications, largely because all of our [heating, ventilation and air conditioning] systems are using electric motors. And so when we can use an efficient controller or drive for that motor, we can save up to 35% in energy costs.”

Von Jouanne said electric motors are wise to pursue instead of internal combustion engines in transportation applications because they are very efficient over their entire speed range, from start to full speed.

“[Electric ships] use their energy more efficiently because electricity in the ship is easier to direct into different parts of your system,” Ph.D. candidate in electrical engineering Caleb Li said. “[For example] you can use all your energy generated by the gas turbine to be in the propulsion system, so it can move faster or for weaponry. So flexibility, more efficiency and the energy’s controllability are the benefits.”

Li said his role in the project is to work on the motor drive system. He said the technology has advanced from motor drives using silicon semiconductor technology to advanced semiconductor technologies.

“My project is to advance the silicon technology to wide-bandgap technology, which has higher power density,” Li said. “It can make the power electronics components smaller, faster and more efficient.”

Von Jouanne said for their primary U.S. Navy contract, they are looking to ensure the motor bearings can handle the operation with advanced wide-bandgap semiconductor switch technology.

“[The project] has now progressed to developing these advanced bearings and really understanding what this new advanced switch technology means for the Navy’s advanced motor drive systems,” von Jouanne said.

Von Jouanne said for their second U.S. Navy contract, the Naval Postgraduate School has developed other low power solutions to solve the adverse effects of the advanced switch technology.

“Namely, to eliminate the common-mode voltage that causes damaging bearing currents, and so we are working to advance that approach to higher power levels that the Navy would use for their motor drive systems,” von Jouanne said.

Von Jouanne said while they aren’t finished with the projects, their preliminary results include advanced bearings with a conducting grease to ensure no bearing damage.

Li’s project for the Naval Postgraduate School contract is moving forward, with advances on a four-leg inverter that prevents bearing damage and has never been used in motor drive applications until now.

As this project relates to sustainable transportation, von Jouanne said she sees these motor drive developments used in transportation applications in a much more sustainable way.

“We’re talking about electrified aircraft, we’re talking about renewable energy applications such as wind turbines, etc.” von Joanne said. “This same type of advanced motor drive technology would also really advance the sustainability of many applications.”