PI: Javad Khazaei
University: Lehigh University
Industry partners: Duquesne Light Company, Siemens, and Siemens R&D
The rapid growth of residential- and community-scale inverter-based resources is creating new protection challenges in low-voltage distribution networks across Pennsylvania. In single-phase AC microgrids, multiple inverters, often with heterogeneous control characteristics such as grid-following and grid-forming-capable units, operate in parallel and interact dynamically with the grid. Although IEEE 1547 [1] defines interconnection requirements for individual inverters, the system-level protection behavior of multiple interacting inverter-based resources remains insufficiently understood. Limited fault current contributions and fast voltage and frequency transients during disturbances can lead to nuisance tripping, unnecessary disconnection of distributed energy resources, and increased customer interruptions, posing reliability risks as grid modernization accelerates.
This PITA project addresses these challenges by designing and experimentally evaluating protection strategies for single-phase AC microgrids with multiple hybrid inverters operating in grid-connected mode. The project will use a realistic hardware-based test bed that emulates real-world operating conditions, including inverter interactions, grid disturbances, and abnormal dynamics, combined with industrial-grade Siemens protection equipment. This approach enables systematic assessment of protection performance beyond what is possible through simulation alone.
The project establishes a new collaboration between Lehigh University, a Pennsylvania electric utility (Duquesne Light Company), and industry (Siemens), integrating academic research, utility-driven needs, and industrial protection technologies. Duquesne Light Company is advancing grid modernization through the development of a state-of-the-art inverter laboratory focused on solar inverter integration and IEEE 1547 compliance. Through this partnership, DLC and Lehigh University’s INTEGRITY Laboratory will jointly develop and validate a sophisticated experimental platform for studying both grid-connected and off-grid inverter behavior. Aligned with the mission of the Pennsylvania Infrastructure Technology Alliance and PA DCED, this project will generate practical, deployable insights that improve microgrid protection, enhance grid reliability, and support the safe expansion of inverter-based resources, delivering tangible benefits to Pennsylvania residents and strengthening the commonwealth’s leadership in advanced energy infrastructure.