Sudip K. Mazumder receives two new grants on power electronics

Professor Sudip K. Mazumder has been switching his attention between two big projects this semester, working to pack power into a high density onboard electric vehicle charger, and precisely control the amount of power and energy flowing to surgical cutting tools. Mazumder, a professor in the Electrical and Computer Engineering Department and the director of Laboratory for Energy and Switching-Electronic Systems (LESES), is the recipient of two grants funding this work: a Small Business Technology Transfer (STTR) Phase I grant from the NSF titled, “Integrated GaN FET based high density on board EV charger,” sponsored by Tagore Technology; and a National Institute of Health grant (with the University of Illinois at Urbana-Champaign) titled, “CPS: Autonomous Attainment of Tissue-Centricity in Electrosurgery through Data-Driven Persistently Evolving Thermogeometric Adaptivity.”

The NSF grant, which began in July 2019 and builds on broad research Mazumder has been pursuing for several years, has a very aggressive goal of developing a high-power gallium-nitride (GaN) transistor based onboard charger to be used on electric vehicles (EV). By eliminating the need for long charging times, an onboard charger could enable broader adoption of EVs.

“You’d be able to take your AC cable and connect it to the EV; everything you need is onboard,” Mazumder said. “But the challenge is, how do you fit the high-power charger in the EV, given that space is a premium. The electronics needs to be small and light. And, it has to be highly efficient, with a high-power density and specific power.”

As you make things smaller, heat becomes a major problem, so increasing efficiency is key. Mazumder is targeting 98 percent efficiency for his onboard system; current offboard chargers are in the range of 96 percent.

“As you approach such high efficiencies, the design becomes exponentially difficult to realize,” Mazumder said.

He is targeting a Level 2 EV charger specification for the onboard charger, but the technology can be scaled for higher power (and reduced charging time) by either having multiple charging modules working together, or using a three-phase input power. For sake of comparison, Level 2 external chargers are typically what you would find in a public space such as parking garages and offices, and have faster charging times than what can be achieved by simply plugging an EV into a 120 volt wall socket in your home.

The NIH grant is a project at the confluence of engineering and medicine, involving multiple researchers from the University of Illinois system at both the Urbana-Champaign and Chicago campuses. Mazumder is the sole engineering expert from UIC on the project.

Electrosurgery has risen in popularity, and the tools, which incorporate laser beams and harmonic/oscillating instruments, have proven to be an affordable, effective tool for surgeons. Presently, they are typically operated at a fixed power level, sometimes damaging tissue and causing complications from excessive voltage. To mitigate these side effects, Mazumder is working on a distributed power electronics system that can precisely control the flow of energy during surgery.

“This is a revolutionary concept. If you can perform surgery without collateral damage, then the patient will recover more quickly,” Mazumder said.

The power will vary based on the type of tissue, the thickness of the tissue, location, and tissue impedance.

“We are just initiating our work on this project, and there is a lot of promise. But, a lot of the multi-dimensional challenges are there: the switching controls, the device and triggering, the electronics, the energy controls. We need to find an optimal solution to the difficult design challenge” Mazumder said.