Time: Friday, March 11 from 1:00 PM - 1:50 PM EST

Location: Via ZOOM ,  download calendar file

Presenter 1: Min Lin, PhD Student, University of Tennessee

Title: High Insulation Voltage Auxiliary Power Supply

Abstract:  Medium voltage (MV) converter with high voltage SiC devices is being investigated to promote the integration of distributed energy resources (DER), such as solar power and grid-scale batteries. The medium voltage converter can serve as an energy transactive hub that is capable of interfacing, controlling, and coordinating DERs as well as new loads such as electric vehicle chargers, smart homes, and data centers. It is one of the fundamental technologies that would make the grid more sustainable, reliable, and flexible, which ultimately improves overall energy efficiency and cuts carbon emissions. A reliable auxiliary power supply that powers the gate driver and control circuits is indispensable in the proper function of the new generation SiC devices in MV converters.

The auxiliary power supply (APS) is required to withstand high insulation voltage of 20 kV in utility applications of 10 kV SiC MOSFETs. Different topologies for the power supply are examined. Transformer design and insulation material that offer reliable insulation voltage are compared. The goal is to build a compact and standardized APS that can be easily placed near the power submodule in a MV converter. Another target of the APS is to achieve a coupling capacitance smaller than 5 pF, which reduces the common mode current imposed by the high dv/dt during device switching.

Biography: Min Lin is presently a Ph.D. student in the department of electrical engineering and computer science at The University of Tennessee, Knoxville, TN, USA. She received her B.S.E.E. degree from North China Electrical Power University in 2019 and M.S.E.E degree from UTK in 2021.Her research interests include medium voltage MMC converters and high voltage auxiliary power supplies.

Presenter 2: Jingjing Sun, PhD Candidate, University of Tennessee

Title:  GaN-based High-Efficiency T-type Totem-Pole Rectifier with Full-Range ZVS Control and Reactive Power Transfer Capability

Abstract: This work proposes a high-efficiency single-phase GaN-based rectifier, which has the capability of reactive power transfer and can be used in the front-end power supplies as an efficient alternative to centralized power compensators for reactive power compensation. A full-range zero voltage switching (ZVS) modulation for both unity power factor (PF) operation and non-unity PF operation is proposed for the GaN-based rectifier in critical conduction mode (CRM) operation. Also, a GaN-based T-type totem-pole rectifier is proposed to overcome the control challenge in CRM during the ac voltage zero-crossing. To implement the ZVS operation and reactive power regulation, a digital-based control scheme is developed. A 1.6 kVA prototype of the GaN-based CRM T-type totem-pole rectifier is built and demonstrated with full-range ZVS operation, 98.9% full-load efficiency, and flexible reactive power regulation with smooth dynamic response.

Biography: Jingjing Sun received the B.S. degree in electrical engineering from Xi’an Jiaotong University, Xi’an, China, in 2016, and the M.S. degree in 2018 from the University of Tennessee, Knoxville, USA. She will receive her Ph.D. degree in electrical engineering in May 2022 from the University of Tennessee, Knoxville, USA. Her research interests include applications of wide band-gap semiconductor devices, high-efficiency converter design, and data center power distribution system modeling and emulation.

Watch the recorded seminar

Upcoming CURENT Power and Energy Seminars

March 18 - Spring Break, no seminar

March 25 - Fei Lu - High Efficiency Solid State Circuit Breaker for MVDC System Applications

April 1 - Timothy Fritch, TVA - Solar Overview

April 8 - Le Xie, Texas A&M - An Open-access Cross-domain Approach to Analyzing the Impact of Extreme Events on the Electricity Sector: What We Learned from COVID-19 and 2021 Texas Winter Outage

April 15 - Spring Break, no class

April 22 - Agasthya Ayachit, Mercedes Benz - eDrive Platforms and Power Electronics

April 29 - Natt Praisuwanna & Pay Kritprajun, University of Tennessee - Fault detection in inverter based grids / reactive power allocation among PV inverters

May 6 - Rupy Sawhney, University of Tennessee - People-Centric Operational Excellence Model

May 10 - Joe Zhou, Kettering University - Energy Storage Systems