Rachel Yang

MIT

Position: Ph.D. Candidate
Rising Stars year of participation: 2024
Bio

Rachel Yang is pursuing her PhD in electrical engineering at MIT. She earned her SB and MEng degrees in electrical engineering from MIT in 2018 and 2019, respectively. Her research focuses on designing and modeling power magnetic components to improve the energy efficiency of power electronics applications, especially under high-frequency operation. Rachel has received the National Science Foundation Graduate Research Fellowship, the MIT School of Engineering Distinguished Energy Efficiency Fellowship, and the MIT E.E. Landsman Fellowship. She has received a best paper award at IEEE COMPEL and outstanding presentation awards at IEEE APEC. Outside of research, Rachel is a Communication Fellow at the MIT EECS Communication Lab, where she coaches students on technical communication skills and teaches workshops. She is also a science writer who has published articles in MIT News and has written video scripts for TED-Ed.

Areas of Research
  • Circuit Design
Developing efficient inductors for power electronics

Electrical systems, from smartphones to electric vehicles, require different types of power to operate. To deliver the required power, power electronics convert power between different forms, but in doing so, they lose energy. This energy loss can limit the performance of electrical systems, so improving the energy efficiency of power electronics is essential for advancing technology. For example, more efficient power electronics can reduce the energy consumption of data centers or accelerate the electrification of aircraft. Currently, the efficiency of power electronics is mainly limited by their magnetic components, such as inductors and transformers. Achieving highly-efficient magnetics, though, is challenging, as different approaches are needed for different classes of power electronics. My research goal is to make highly-efficient magnetics design easier by developing new structures, models, and design guidelines across different applications. In pursuit of this goal, I have developed two types of inductors that cut inductor energy losses in half. The first type is a modified pot core inductor that uses a special modular structure suitable for power electronics with large ac currents. Prototypes of this inductor have enabled two high-performance power electronics systems: a 660W power converter with a power efficiency of 98% suitable for uninterruptible power supplies for backup power; and a 70W wireless power system with an efficiency of 94% suitable for phone chargers. The second type of inductor is a permanent magnet hybrid core inductor that unconventionally combines multiple magnetic materials and is suitable for power electronics with largely dc currents. This inductor may improve size- or weight-constrained applications, such as by extending the battery life in smartphones or drones. Going forward, I will continue to develop a framework for designing highly-efficient magnetics across different power applications and thus advance power-critical technologies.