Ulrich Munz, of Siemens Corporate Technology,Â describes a federally funded research project to make the US power grid more resilient and reduce the length of outages. Among other things, researchers will explore splitting the grid into several microgrids.
Severe storms can cause massive power outages. In September 2018, Hurricane Florence cut off the power supply to hundreds of thousands of people in North Carolina for several days. Between 2017 and 2018, 25 million people in the US experienced power outages for more than one hour. Compared to the European power grid, where much of the power line infrastructure is buried underground, the power grid in the US may be more vulnerable to natural disasters due to the pervasiveness of overhead power lines. US power lines stretch over thousands of miles and sometimes to remote areas, such as densely forested mountains.
â€śWhen a tree branch touches a power line, a chain reaction can start that takes entire regions off the grid as was the case for the major power outage in the Northeastern United States in 2003,â€ť MĂĽenz said.
MĂĽenz will be leading the AURORA (Autonomous and Resilient Operation of Energy Systems with Renewables) project in partnership with the National Renewable Energy Laboratory (NREL), Columbia University School of Engineering, and Holy Cross Energy. Over the next three years, the AURORA project team will develop a range of functions and assistance systems to make power systems in the US more resilient.
Depending on the state of the power grid, the researchers will split the grid into several microgrids to supply electrical loads either individually or collectively. Microgrids are playing an increasingly important role as power generation becomes more decentralized. Siemens has multiple microgrid controllers for this reason and has used them in several research, pilot, and commercial projects all over the world.
In the first stage of the project, Siemens is working with Columbia University to enable network operators to detect critical events faster and identify root causes. The aim is to detect power line failures due to physical incidents as well as cyber attacks on substations or control centers.
â€śWe compare the real behavior in the power grid with its digital twin to quickly identify the cause of a malfunction,â€ť says MĂĽenz.
Additionally, preventive measures are investigated to prepare the power grid for predictable disruptions.
â€śIf the connecting line to a remote town leads through a wildfire area, the town can be prepared for a failure on this line by starting local generation units, such as diesel generators,â€ť says MĂĽenz. Thus, power outages in remote towns can be prevented.
In the second stage, the research project will investigate maintaining the power supply after cyber attacks on the grid control center or the communications network. According to MĂĽenz, the aim is to ensure that in the event of a control center failure, the microgrids coordinate with each other to continue supplying power to critical loads, such as hospitals. In the AURORA project, researchers from Siemens and NREL are developing new control methods for coordinating microgrids, which automatically balance the decentralized generation and load in such a way that no further failures occur.
It will soon no longer take several days to restore power after a complete outage, such as the one caused by Hurricane Florence. Currently, the power grid must be manually restored by gradually connecting large conventional power plants to the grid and then connecting loads within cities and industrial plants. This can be a very time-consuming process due to human intervention and the risk mitigation processes that must be followed to protect field workers. In the AURORA project, Siemens and NREL are investigating a revolutionary bottom-up system restoration approach â€” restarting the grid by automatically reconfiguring and collectively stabilizing the grid after a blackout using existing decentralized generation units.
â€śWe are developing special control functions that can make an autonomous black start within microgrids possible,â€ť says MĂĽenz. These control functions can be installed in smart inverters of residential solar power systems, batteries, or wind turbines.
Each research partner is contributing their unique expertise to the AURORA project:
These innovative solutions should allow the power grid to be more resilient to cyber attacks and natural disasters while providing more autonomous restoration of electricity after power outages.
Ulrich Munz is a principal investigator for the US Department of Energy SETO ( Solar Energy Technologies Office) Project AURORA atÂ Siemens Corporate Technology.Â This post originally ran on the Siemens Ingenuity blog.Â