Undergraduate research enables big steps forward for small-scale power grids

// Electrical & Computer Engineering

Tags: Electrical and computer engineering, Energy, interdisciplinary research, microgrids, power, summer research, Sustainable Energy, undergraduate research, WEMPEC

Undergraduates in a lab
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Research is often an empowering experience for undergraduates, but for six students who spent the summer of 2016 at the University of Wisconsin-Madison, their efforts generated results that could also help bring power to people around the world.

The team worked to develop small, self-contained electric power grids, or microgrids, under the guidance of Giri Venkataramanan, a professor of electrical and computer engineering at UW-Madison, and Ashray Manur, a graduate student in Venkataramanan’s group.

In the developed world, most people plug in to major metropolitan power grids—hundreds of thousands of homes connected by miles and miles of high-voltage transmission lines drawing power from massive far-off plants. And rarely do they consider the mind-boggling amounts amount of infrastructure and highly sophisticated algorithms that keep the system humming along.

Until the system stops humming.

Nicole Bugay explains the layout of a circuit board that can convert direct current power, such as would come from a solar panel, to alternating current, which is what powers appliances in most homes.
Nicole Bugay explains the layout of a circuit board that converts direct current power, such as the output of a solar panel, to alternating current, which is what powers appliances in most homes. (Photo: Stephanie Precourt)

“Hurricane Wilma [in 2005] made me realize realized how dependent we are on the grid,” says Nicole Bugay, a visiting student from Florida. “We were without power for a week, which sparked my interest in solutions for off-grid renewable energy.”

Microgrids empower people to take control of their own electricity generation without the need for massive metropolitan infrastructure. Beyond keeping the lights on in case of emergency, microgrids could bring power to people in remote parts of the world.

“A community can come together to buy a diesel generator or solar panel array, even though each home couldn’t afford such expensive equipment by itself,” says Manur. “But the community needs to control power distribution between and within each house, which is what microgrid technology enables.”

Venkataramanan’s group has been working for several years to develop the necessary hardware, software and firmware to monitor and control electricity flow for single homes or small communities. In the lab, they test prototypes using small-scale approximations of houses perched on laboratory carts.

Although the miniature homes completely lack comfortable furnishings and decor, they do feature LED lights, fans, stereo speakers, and USB outlets to charge personal devices. Most importantly, each cart comes equipped with a circuit-board brain: the microgrid manager that monitors and controls energy use.

Boards like those in the lab have been demonstrated in microgrid pilot installations in the Democratic Republic of the Congo, thanks to a partnership with Madison-based start-up NovoMoto, which was founded by two UW-Madison engineering graduate students.

“NovoMoto evolved as our No. 1 beta-test partner,” says Venkataramanan. “They tell us the changes they’d like to see. The larger project is always to make microgrids more field-ready.”

And the team of summer students made significant progress on that front in just a few short months.

For example, student Alec Sivit developed algorithms so that users can control the microgrid manager wirelessly using text messages, while Ben Chylla and Sam Sivit developed web-based and mobile apps to monitor power consumption.

“It came together organically because we had electrical engineers, computer engineers and computer science students working together or in parallel,” says Venkataramanan.

Working on microgrids requires broad skillsets, but the students eagerly rose to the challenge.

“One day we’re working on designing a printed circuit board and the next day we’re writing cloud computing software for it,” says Manur. “Integrating all of the components is the most fun and also the most challenging part of the research.”

One challenging project involved overcoming a major obstacle to implementing microgrids in developed nations. While microgrids can draw power from a variety of sources, such as diesel generators, solar panels, and even 12-volt car batteries, all of these output direct current (DC) power. Modern houses and appliances are wired for alternating current (AC). Students Nicole Bugay and Anna Lunes designed control boards capable of converting DC to AC.

“Anna and Nicole’s work is the bridge that helps us get to the real world. It’s a critical step that brings us from DC, which is limited, to real-world houses,” says Venkataramanan. “And, at the end of the summer, we’re ready to print circuit boards based on their designs.”

Lunes, who originally hails from Rio de Janeiro, Brazil, will test prototypes of her designs in the houses-on-carts during the first few months of the fall semester. Eventually she hopes to bring the technology back to her home country. And thanks to the system’s wireless capabilities, her colleagues in Madison could link to a Brazilian microgrid from right here in the Badger State.

Venkataramanan attributes the students’ significant progress toward field-ready microgrids to the group dynamic established over the past few months.

“Generally we have one or two students working summer lab with the grad students. This is the first time we’ve had a whole team working toward the common theme of enabling technologies to move our microgrid prototype systems further,” says Venkataramanan.

Students will continue improving the technologies during a special topics class offered at UW-Madison during the fall 2016 semester. Additionally, one of Venkataramanan’s graduate students is currently working with researchers in India to wire up four houses-on-lab-carts to test the microgrid managers on the other side of the world. Due to the circuit boards’ wireless communications capabilities, the systems will transmit performance data to Madison, which will help inform the design of future field tests.

The undergraduates received support from a National Science Foundation program for Summer Undergraduate Research Experiences.

Author: Sam Million-Weaver