ComEd Simulates Islanding with its Bronzeville Community Microgrid
The Bronzeville Community Microgrid (BCM) took one more significant step toward fruition when a simulated islanding test was successfully completed on April 16, 2019. This field-test provided further evidence that the technology that had already been demonstrated in the lab will provide substantial value to the community by making it more reliable, resilient, and sustainable.
Microgrids are electrically defined portions of the grid, which are powered by distributed energy resources (DERs) including solar photovoltaics (PV) and energy storage and can operate either in conjunction with the wider grid or as an island. On Feb. 28, 2018, the Illinois Commerce Commission issued a final order for ComEd, the electric utility serving Northern Illinois and Chicago to install the first utility-operated microgrid cluster.
What is the Bronzeville Community Microgrid?
The BCM will serve residences, businesses and public institutions, including the headquarters of the Chicago Fire and Police Departments, and demonstrate technologies that will support the integration of DERs and provide further resilience capabilities when they are needed the most.
To power this microgrid, DER including battery energy storage systems (BESS), solar PV, and controllable generation will be used. After issuing a request for proposals, ComEd purchased and installed 500 kW/2 MWh of BESS. Factory acceptance testing (FAT) was performed prior to deploying the asset in the microgrid footprint where extensive site acceptance testing was completed. Though ComEd will not own the solar or controllable generation, it also issued a request for proposals (RFP) to purchase the distribution capacity. For the purposes of solar RFP, the distribution capacity was defined as the right to use the generation during periods in which the microgrid is islanded whether as part of testing, or because of a disruptive system event. ComEd purchased the capacity for the solar PV, which has been installed on the rooftops of the Dearborn Homes, a facility of the Chicago Housing Authority and part of the BCM. The responses for the controllable generation RFP were received in April 2019 and are being evaluated for engineering viability.
ComEd is installing the BCM in two phases. In the first phase, which was completed with this successful test, upgrades were first done on one of the feeders being used for the microgrid to enable the installation of the technology. Then, solar PV and energy storage were installed and tested individually. A mobile generation was then deployed for testing purposes. In the second phase, scheduled to be completed in the first half of 2020, feeder work on the second microgrid feeder will be done, along with the installation of the controllable generation and deployment of a cutting-edge microgrid master controller to control and monitor the technologies deployed for this project.
Once the project is completed, it will serve as the flagship of the Bronzeville Community of the Future, where ComEd is collaborating with the community to identify opportunities to leverage smart grid and emerging energy technology to enhance everyday life. Pilots include an electric vehicle (EV) transportation service for seniors; off-grid wind and solar LED streetlights; a community energy storage pilot; a smart interactive kiosk that provides real-time information along with emergency alerts, wayfinding and public wi-fi; and sensor-based technologies that are being piloted in conjunction with Illinois Tech, a longtime ComEd collaborator widely known for its strong engineering curriculum. Several STEM education programs are also underway to engage area high school students and expose them to emerging energy technology and related career paths.
Demonstrating in the Laboratory
Before this can be done, however, many of the technologies needed to be developed and tested to ensure that they could be safely and effectively deployed. The BCM project includes the demonstration of cutting-edge technologies that will help make the entire grid more resilient and sustainable. ComEd received three grants from the Department of Energy (DOE) to support projects, including a microgrid-integrated solar storage technology (MISST) which will support efforts to integrate greater amounts of renewable generation to the grid.
The MISST is the culmination of multiple innovations, including the development of a smart inverter that has grid-forming capabilities. Though much popular attention has focused on the deficits of relying on intermittent generation like solar PV, this capability of smart inverters helps mitigate the adverse impacts. It connects the solar PV with forecasting capabilities that consider when the sun is likely to shine, along with energy storage that does solar smoothing. The decision of when to charge and discharge the battery is made by the microgrid master controller, which will operate the BCM, and was enhanced as part of this project.
To develop and demonstrate this technology, ComEd used its Grid of the Future Laboratory. This laboratory, which is sited in two locations, including the Chicago Tech Center on the South Side of Chicago, and in Maywood Illinois, has capabilities that help ComEd maximize the value of these emerging technologies. For example, the laboratory includes a power hardware in the loop and control hardware in the loop capabilities, that allow the testing of both the smart inverter and the microgrid master controller, respectively. These technologies were demonstrated using a real time digital simulator (RTDS), which makes it possible to consider hundreds of realistic scenarios.
In March, ComEd demonstrated the technology at the laboratory in an on-site visit by the DOE and industry partners. Following the successful presentation, the DOE issued ComEd a go-order, allowing it to begin the third and final budget period of the project.
Preparing for Field Demonstration
As a next step, ComEd sought to conduct a simulated island test of the BCM to provide an opportunity to observe the efficacy of the technology in the field. As utilities deploy cutting-edge technologies which can impact customers, it becomes ever more crucial to provide multiple opportunities for company personnel to gain experience with these technologies in a safe manner. The RTDS capability in the Grid of the Future Laboratory offers the utility an equivalent of a flight simulator for equipment, in which they can refine the software and settings they are developing in a safe manner. The simulated island test offers an additional opportunity to provide experience not just to the employees operating the technology, but also to stakeholders, to have a deeper understanding of how the grid of the future will function.
To mitigate any potential unforeseen circumstances, switching was done to provide load relief to the relevant feeder to limit customer exposure. In addition, customers were informed about the test so that they may know what might happen.
ComEd established a mobile response unit which included a mobile command center sited at the battery energy storage unit, as well as a War Room, at the Illinois Tech campus near the location of the BCM. The War Room was led by ComEd Vice President of Engineering and Smart Grid, Shay Bahramirad, and included personnel from a wide range of groups, including Testing Group, Smart Grid, and Capacity Planning, as well as external partners and contractors from institutions such as Quanta Technology, Siemens, Lockheed Martin, Illinois Tech, and the University of Denver.
The Field Demonstration
Though microgrids are designed to make it possible for residents to be safer during a disruptive event, the first priority of that day was to ensure that even when it was being tested, all remained safe. On April 16, dozens of personnel, from testing engineers to ComEd executives, began by participating in a safety briefing that prepared them for what might come. The goal of the day was to demonstrate three types of capabilities of the BCM system; islanding at unity power factor, a lagging power factor, and a leading power factor, which would provide a broad sense of the islanding capabilities of the microgrid.
During the testing, the generator, the BESS and the PV system were used to control both the real and reactive power flows across the microgrid point of interconnection (POI). Three tests were conducted in which various DER were able to maintain the power flow at the POI close to zero.
Having successfully completed the three testing scenarios required to achieve planned islanding, the team successfully demonstrated the capability of the BESS to support the transition to planned islanding, supporting efforts to prepare for the actual islanding test later in 2019. The lessons learned from this effort will support refinements to the planning and design of the full microgrid.
What’s Next?
As the grid changes with the increased penetration of DERs and the greater appreciation of the needs for sustainability and resilience, the demonstration of emerging technologies becomes ever more important. This not only entails their evaluation in the laboratory, but also in innovative tests.
When the ICC issued the order for this microgrid project, it noted that it “encourages the kind of innovative pilots such as the Project which have the ability to inform myriad stakeholders about DER and the use of grids. Pilot programs, such as the Project, are appropriate ways to test new technologies because of the smaller-scale, lower-cost abilities of a distinct sample size, which has wide-reaching application both in Illinois and across the country.”
Implementing these pilot projects, however, requires developing new skills in order to collect these new lessons learned. With demonstrations like this, however, ComEd is leading the way towards a more resilient and sustainable grid.
