Collaborative Research: Highly Compact, Multi-port, GaN-Based Grid-Forming Inverter

University Of Texas At Austin, Austin TX

Investigators

Abstract

Weather-related disasters are sobering reminder of the "growing pains" that accompany the electric energy transition towards renewable generations. Addressing such challenges will require renewable resources to be designed to support the grid when needed instead of tripping offline during these times. This will require a new grid-forming inverter technology. This project brings together a joint team from the University of Texas Austin and the University of Central Florida, to develop a high efficiency, high power density grid-forming solutions to enable a more resilient grid. The team has previously developed and verified several key innovations such as the basic grid-forming control, control of multi-port inverter, and control of multilevel three port inverter. The project supports US’s energy transition to a renewable energy-based future, and it will enable higher penetration of solar energy into the grid by delivering an integrated, efficient, and reliable solar plus storage solutions. This PV plus storage microinverter systems will provide a reliable renewable energy asset for the grid, thereby lessening the nation’s dependence on fossil fuels and creating a grid that is more resilient and stable. The integration of the storage in the microinverter itself could generate new business models, enabling the owner and utility new degrees of freedom in grid control and energy flexibility. This project will result in technological advancements in grid-forming control methodology as well as the advancement of using wide bad-gap GaN power devices based three port multilevel inverter. In terms of frequency response, the project will study and valid a novel Adaptive Frequency Position (AFP) concept which will move grid-forming control beyond the traditional synchronous generation inertia emulation. Innovative three port multilevel inverter topology will be studied and used to realize a high performance GaN microinverter with PV and storage connectivity. The proposed collaborative project will enable the team to work together to advance the GFM controls beyond the basic functionality, study the stability when multiple grid-forming and grid-following inverters work together, as well as to develop a GaN based grid-forming microinverter and testbed. The main technical objectives include: 1) Optimization of grid-forming voltage control loop bandwidth and filter design. 2) Advanced functionalities for three-port microinverter with black start, automatic islanding, MPPT, reactive power support functionalities in addition to the frequency support; 3) Advanced control beyond inertia emulation 4) Design of advanced three port microinverter beyond the state of the art in microinverter technology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.