Researching pathways to reliable electricity delivery

Customers rely on electric utilities to deliver reliable electricity to their homes without interruption. Duquesne Light Company (DLC), a Pittsburgh-area electric utility serving more than 600,000 customers in two counties, knows this well. To better serve its customers, DLC developed its own research lab to explore new technologies, processes, and implementation methods to enhance energy delivery.

DLC partnered with Javad Khazaei, assistant professor of electrical and computer engineering at Lehigh University, to explore this effort. Khazaei leads the INTEGrated, Resilient, and IntelligenT energY systems (INTEGRITY) Lab at Lehigh University, where his team studies grid challenges in a laboratory setting.

The electric power grid that supplies most modern infrastructure operates predominantly using alternating current (AC). AC power is the standard for bulk generation and long-distance transmission. It is produced at power plants, stepped up to high voltages for efficient transport over transmission networks, and then stepped down through distribution systems before being delivered to homes and industries.

In contrast, direct current (DC)-based architecture offers several technical advantages at the system level, including simpler protection coordination, more straightforward power-flow control, and fewer conversion stages for inherently DC resources and loads. Consequently, DC is often considered more efficient and cost-effective in certain applications, particularly in modern grids with high penetration of power electronics, renewable energy sources, storage systems, and data-center-type loads.

In this collaboration with Khazaei’s team of researchers, DLC wanted to investigate the development of a DC power grid.

“This is part of DLC’s grid modernization plan,” Khazaei says. “Instead of having an AC utility system, they wanted to explore the feasibility of localized DC systems serving different districts. They were testing to see what kinds of issues they might face if they operated these DC systems.”

Since this work aligns with DLC’s future plans, the research team developed recommendations for controlling and protecting DC grid systems.

Khazaei says, “This research developed a computationally efficient equivalent fault model for grid-interlinking converters in DC microgrids, enabling accurate prediction of transient and steady-state responses to grid-side symmetrical faults and supporting large-scale resilience assessment without the heavy computational burden of detailed electromagnetic transient simulations.”

Establishing a viable DC grid architecture has the potential to reduce system costs through improved conversion efficiency and simplified protection schemes while enhancing resilience to faults and disturbances. The research conducted by Khazaei’s lab on modeling and protecting DC microgrids can contribute to more reliable and cost-effective power delivery to end users over the long term.

A similar collaboration was initiated in 2025 between the INTEGRITY Lab and DLC to evaluate microgrid components, including grid-forming and grid-following inverters, protection devices, and real-time simulation platforms. To avoid the operational risks and service disruptions associated with testing on energized utility infrastructure, DLC established an in-house research and validation laboratory capable of emulating a range of operating conditions.

Within this environment, DLC engaged Khazaei’s team to support the design and development of an AC microgrid test configuration composed of multiple hybrid inverters capable of operating in both grid-connected and islanded modes. The primary objective was to characterize the dynamic performance and protection behavior of commercially available inverters under realistic scenarios, including fault events, large load transients, and other system disturbances.

The study can also inform further research into protection devices. Jessica Valentine says, “The research performed by Lehigh University under the award for integration of distributed energy resources (DERs) to the grid via DC interlinks provided valuable information on protection requirements of DERs for grid integration, which informed potential investment planning for DLC utilities, increased stakeholder engagement, and provided insight into future project pathways.”

Khazaei expects his partnership with DLC to continue, particularly as the power company continues to develop its research program. Lehigh’s facilities, which consist of commercially available products, complement DLC’s facilities. DLC provides parameters for a scenario or a set of operating conditions, and Khazaei uses his lab equipment to perform testing, emulation, and modeling of those faults.

Khazaei is in the process of bringing Siemens into a PITA project with DLC, expanding the collaboration. Josh Gould, director of Advanced Grid Solutions and Enterprise Strategic Planning at DLC, also expresses hope that the connection between DLC and Lehigh University will continue in “future research collaborations with regional partners.”

For Pennsylvania, this collaboration can result in a more efficient and resilient energy grid, offering better service to customers overall. In an era when energy consumption is rising steeply, research into future grid improvements by Lehigh University and DLC can produce the technologies needed to meet that demand, as well as a technically proficient workforce to keep it running smoothly.