Although the United States’ electric grid is an engineering marvel with more than 9,200 electric generating units connected to more than 600,000 miles of transmission lines, it is rapidly running up against its limitations. Consequently, the U.S. Department of Energy has a vision of a future “smart” electric power infrastructure, with a goal of creating a more resilient grid through the use of cutting-edge technologies, equipment, and controls that communicate and work together to deliver electricity more reliably and efficiently.
UNLV’s Yahia Baghzouz of the department of electrical and computer engineering and his graduate students have created a small “microgrid,” a localized grid that can disconnect from the traditional grid to operate autonomously. This mini-grid acts as a test bed to investigate the various devices that will be needed for the smart grid and technologies that will ultimately help with the integration of renewable energy resources into the grid infrastructure.
Small But Powerful
The DOE's Smart Grid Research and Development Program considers microgrids as a key building block for a smart grid as they can, when needed, function independently of the main electrical infrastructure. In critical times, such as power outages, future “smart” grid could break down into these microgrids, which individually could continue to serve customer needs.
“Microgrids can strengthen the grid resilience which is becoming increasingly important in the face of the increased frequency and intensity of power outages caused by severe weather due to climate change.” Baghzouz said.
At UNLV, the team uses the microgrid to test out various devices and technologies that will be needed for the smart grid. It also proves a valuable training ground for the electrical engineers and scientists that will help make the smart grid into a reality.
The engineers have already carried out several experiments using the microgrid, including testing out advanced photovoltaic converters.
“The microgrid allows us to induce real, rather than simulated, voltage and frequency disturbances,” Baghzouz said.
In the near future the UNLV engineers plan to add a battery energy storage system to the microgrid generation fleet. They also plan to develop control systems associated with economic drivers that use time-of-day pricing sometimes in conjunction with peak-demand charges to determine when and whether energy is to be returned to or drawn from the grid.