678698 event 1732796483 1732796601 <![CDATA[Ph.D. Dissertation Defense - Decheng Yan]]> Title:  Gridformer - A New Approach to Stabilize and Manage a High IBR Penetration Grid

Committee:

Dr. Deepak Divan, ECE, Chair, Advisor

Dr. Maryam Saeedifard, ECE

Dr. Santiago Grijalva, ECE

Dr. Daniel Molzahn, ECE

Dr. Jonah Enslin, Clemson

]]> As the integration of intermittent renewable energy sources (IBRs), such as wind and solar, increases, the challenges of transmission line congestion, voltage instability, and power system frequency fluctuations intensify. IBRs, especially those based on grid-following (GFL) control, exacerbate grid stability issues, including overloading of critical components, voltage instability, and the inability to re-establish grid synchronization during faults. While Flexible AC Transmission Systems (FACTS) devices have been used for grid management, their high installation costs, limited fault current tolerance, and reliance on GFL control reduce their effectiveness in dynamic grid support. This thesis introduces a novel solution: the GridFormer, a utility-owned grid-enhancing shunt-series compensator designed to enhance both steady-state and dynamic grid operations. The GridFormer consists of a shunt transformer, a back-to-back (BTB) converter, a small energy storage unit, and a protection relay capable of handling high fault currents. It provides both series voltage and shunt current to stabilize frequency and voltage during grid events, offering improved reliability compared to traditional FACTS devices. A prototype of the GridFormer was tested at Clemson University's eGrid facility, successfully demonstrating its steady-state power flow control up to 800kVA at 24kV. This thesis highlights the GridFormer's design, operational modes, and control strategies, positioning it as a cost-effective, scalable solution to address the grid challenges posed by high IBR penetration in the near term.

]]> <![CDATA[]]> https://teams.microsoft.com/l/meetup-join/19%3ameeting_ODMyMjgwODYtNzQwMy00ZjYwLThjY2YtZjZhZWQwZmQyMzhj%40thread.v2/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%220e409197-eea6-4968-ad2e-b69e0f273617%22%7d 434381 1788 100811 1808