Power Electronics

Electric Machines and Drives

Application of wide-bandgap (SiC) devices for ultra-efficient and high-density converters

Sensorless control of induction motors and permanent magnet motors

Wind power generation using doubly fed induction generators and direct-drive permanent magnet generators

High-power, medium-voltage multilevel converter topology and control

Bi-directional battery charger and drive train design for electric vehicle

Power management in microgrid

More electric aircraft technologies

EMI and filter reduction for high power density power conversion systems with multilevel converters and soft-switching techniques

I joined the electrical energy management group (EEMG) at the University of Bristol as a Lecturer in 2011 after my PhD from Tsinghua University and became a Professor in 2017. I also hold the Royal Academy of Engineering/Safran Chair in Advanced Aircraft Electrical Power Generation Systems. I currently lead a team of 11 researchers (5 post-docs and 6 PhDs) working on power electronics converters and motor drives with active reseach grants of £3.5M as a PI. My current and past work inlcude application of wide-bandgap devices, multilevel converters and wind power generation. We have developed SiC converters from several kWs to 500kW. I am the Director of the UK EPSRC National Centre for Power Electronics, an executive committee member the IET Power Electronics, Machines and Drives (PEMD) network and a Distinguished Lecturer of IEEE Power Electronics Society (PELS). I work very closely with industrial partners with technologies transferred to their products. I am the co-director of Safran-Bristol University Research Centre. 

We deliver training and short courses to industry covering power electronics and electrical drive systems and their recent development. Please contact me for details.  

If you are interested in multilevel converters, wide bandgap devices, wind power generation, high-frequency power loss of magnetic components, you may find the following our publications useful. 

X. Yuan, “Derivation of Voltage Source Multilevel Converter Topologies”, IEEE Transactions on Industrial Electronics, 2017.

J. Wang, X. Yuan, B. Jin, “Carrier-based Closed-loop DC-link Voltage Balancing Algorithm for Four Level NPC Converters based on Redundant Level Modulation”, IEEE Transactions on Industrial Electronics, 2020. 

X. Yuan, Y. Gao, Y. Li, “A Fast Multilevel SVPWM Method based on the Imaginary Coordinate with Direct Control of Redundant Vectors or Zero Sequence Components”, IEEE Open Journal of Industrial Electronics, 2020.

X. Yuan, I. Laird, S. Walder, “Opportunities, Challenges and Potential Solutions in the Application of Fast-Switching Silicon Carbide (SiC) Power Devices and Converters”, IEEE Transactions on Power Electronics, 2021.

X. Yuan, “A Set of Multilevel Modular Medium Voltage High Power Converters for 10MW Wind Turbines”, IEEE Transactions on Sustainable Energy, 2014.

Y. Zhang, X. Yuan, M. Al-Akayshee, “A Reliable Medium-Voltage High Power Conversion System for MWs Wind Turbines”, IEEE Transactions on Sustainable Energy, 2020.

X. Yuan, F. Wang, D. Boroyevich, Y. Li, R. Burgos, "DC-link voltage control of a full power converter for wind generator operating in weak-grid systems", IEEE Transactions on Power Electronics, 2009. 

X. Yuan, Y. Li, "Control of variable pitch and variable speed direct-drive wind turbines in weak grid systems with active power balance", IET Renewable Power Generation, 2014.

J. Wang, K. Dagan, X. Yuan, W. Wang, P. Mellor, “A Practical Approach for Core Loss Estimation of a High-current Gapped Inductor in PWM Converters with a User-friendly Loss Map”, IEEE Transactions on Power Electronics, 2019.

J. Wang, X. Yuan, N. Rasekh, “Triple Pulse Test (TPT) for Characterizing Power Loss in Magnetic Components in Analogous to Double Pulse Test (DPT) for Power Electronics Devices”, IEEE IECON 2020.

Teaching

I teach units related to power electronics, electrical drive and power systems. For example, I teach EENGM0001 Advanced Power Electronics Design, where you can learn how to use practical software to design control loops, printed circuit boards (PCBs), and practical hardware design considerations. More importantly, you will learn how to apply what you have learned in your previous years in real applications, e.g. in DC/DC or DC/AC converters. Cutting-edge research such as wide-bandgap power electronics will also be taught in my lectures.

Also, I arrange field trips for the students to visit industrial design and manufacture sites as part of the lectures to experience the 'real' power electronics devices and applications.      

Some feedback from previous students:

"Thank you for engaging the class with this company and arranging the tour, it was a fantastic insight as an undergraduate.

I would encourage you and other lecturers to continue to provide these experiences to students as they are much appreciated."