Smart Grid Test Facility: An Educational Tool for Power Engineering Students
By Marissa Petersile, Christopher Powers, Tim Leung, Suleyman Kahyaoglu, and Jeremy Kramer
The Smart Grid Test Facility is an educational tool for engineering students, providing an environment for testing and demonstrations regarding the power grid. This system was designed and constructed by a team of five students at Boston University within the Electrical and Computer Engineering Department.
The power grid suffers from numerous engineering challenges, from century-old infrastructure to intermittent distributed generation; its tasks continue to surface and expand across the energy industry. The power grid is dynamic, bound for change, and yearning for innovators—we need to get engineers and scientists excited about the grid and participating in real, hands-on power engineering. The Smart Grid Test Facility aims to do just that.
The Smart Grid Test Facility is an educational tool for engineering students, facilitating in-class experiments, demonstrations and active learning. The fundamentals of the grid can quickly become masked behind striking transmission towers, controversial reports surrounding renewable energy and indiscernible one-line diagrams. With this system, we provide a simple environment where students can observe, interact with, and understand the power grid for what it is: generation, transmission, distribution and loads. Students must understand the grid before learning about the concepts and development of smart grid.
The technical approach involves breaking down the small-scale grid into its main components, integrated to create a mobile, classroom-friendly system. The test facility was designed and constructed at Boston University. The lowest shelf houses the two mechanical generators, the middle shelf holds the feedback control loops and power supplies, and the top shelf is an interactive space, where students synchronize the generators into the transmission line network, connect loads and make measurements.
When a new power plant—say, a solar farm or coal plant—joins the power grid, it must synchronize its output with the existing signal propagating along the transmission lines. Thus, it is vital in our system to demonstrate the process of synchronization and provide an interactive mechanism for combining generators.
The test facility includes components that address what is necessary for operation of any power system: synchronization, frequency stability, power propagation, power consumption and data acquisition.
We designed synchronization circuits: an LED placed between the existing grid signal and the signal we wish to synchronize to the grid. The LED displays the combination of the waveforms: when the line-to-line voltage is zero, the generators are in phase, and the LED is dim; when the line-to-line voltage is large, the generators are out of phase, and the LED is bright. Thus, when a student sees that the LED is dimmest, he or she closes a main toggle switch to attach the generator onto the existing grid safely and effectively.
Frequency stability is vital to the functionality of the entire grid network. Without feedback control, the frequency of the alternators changes as loads, transmission line lengths and other system properties change. With three generators synchronized, it is vital that the alternators individually remain at a nearly constant 60Hz. This is accomplished via a feedback control loop that is attached to both mechanical generators, which includes a microcontroller and a buck converter.
The resistive, inductive and capacitive characteristics of real transmission lines impact the behavior of a power grid, and in order to demonstrate these impacts to students, we modeled real-grid, interactive and changeable lines. With three transmission line PCBs, modeling 115kV aluminum lines, we have created a triangular layout with generators at each point and transmission lines along the legs—this creates the grid layout.
The purpose of a power grid is to provide power to loads—whether it is a washing machine, a computer charger, a heart monitor, or a motor, the grid supplies power to different types of loads, each with unique demands. Thus, we provided a variety of loads for testing and learning purposes. This includes variable resistive, inductive and capacitive loads, designed on PCBs. We also designed and included an LED array.
The data acquisition system is available so that students can monitor the electrical signals at various points along the grid. In particular, students observe voltage and current waveforms in addition to power factor and phase angle. Students choose which points along the grid they wish to monitor via the collection of sensor board PCBs that are provided with the project. The data acquisition system centers around a MATLAB script activated via the command window. This is the fundamental part of an introduction to smart grid—the ability to monitor real-time data with automated responses.
We’ve developed an environment that teaches students about a power grid. This is vital not only for encouraging students to pursue a career in the power industry, but also to create a platform for fundamental knowledge about a grid. Nonetheless, more work is to be done on this system to make it more applicable to the changes on the grid’s horizon. Looking forward, we aim to incorporate several additions and improvements to this system.
First, we would like to incorporate small-scale smart grid technologies into our project, which would involve smart communication systems. These would likely come from Saturn South, a manufacturer with whom we corresponded frequently at the beginning of the design process. There are also several improvements we aim to make to the sensor system, such as using polarized connectors and allowing for a larger range of measurable currents. Only one construction of this system has been built, and our team hopes to have opportunities to construct more systems as needed by various educational or research programs.
Marissa Petersile, an IEEE and IEEE Power & Energy Society (PES) member, graduated from Boston University in 2015 with a degree in electrical engineering and a focus on energy technologies. She currently serves as an engineer in the Electric Transmission Planning Department at National Grid. Additionally, she is interested in renewable energy technology integration, energy efficiency and smart grid technologies. Marissa became an IEEE PES Scholar in 2015.
Christopher Powers is an electrical engineer with General Dynamics Mission Systems. He received a B.S. in electrical engineering from Boston University in 2015, where he focused on photonics and circuit design. Additionally, he received his military commission in May 2015, and is currently a Second Lieutenant in the United States Air Force Reserve. His areas of interest include integrated photonics, secure optical communications, RF design and infrastructure cyber security.
Tim Leung is an electrical engineer at Braintree Electric Light Department. He is currently involved in substation maintenance, T&D operations, and distribution system management. His areas of interest include distribution substation protection and improving the overall infrastructure of the grid. He received his B.S. degree in electrical engineering from Boston University.
Suleyman Kahyaoglu recently earned a B.S. in electrical engineering with a concentration in technology innovation from Boston University. Throughout his senior year he served as an officer for the Boston University Chapter of IEEE. He is currently pursuing an M.S. in real estate development from the Graduate School of Architecture, Planning and Preservation at Columbia University while conducting research on energy and building materials focused in Tokyo, Japan for the Center for Urban Real Estate.
Jeremy Kramer is a recent graduate from Boston University currently exploring possible next steps both at home and abroad while living in Los Angeles, CA. He worked on development of the Smart Grid Test Facility in his final year at Boston University after spending his last two years at Boston University focusing his studies on power electronics and energy technologies. In the past he has worked with researchers at Boston University to develop electrodynamic screen technology for solar cell maintenance and is looking to enter energy technology R&D in the future.