Nicole Zimmerman is an aspiring electrical engineer. She recently graduated with a bachelor’s degree in electrical engineering; she’ll start graduate studies in the fall. Nicole is a mother of two, a student and a tutor, a member of the Society of Women Engineers Region J, where she’s held several leadership positions and a problem solver dedicated to addressing the challenges of the fast-growing green energy/technology sector.
Zimmerman's interest is in what she calls, "the softer side of engineering": working to find the best ways to provide power to communities, especially renewable power. One way Zimmerman is pursuing this interest is by collecting and analyzing data from the electric vehicle (EV) charging stations on the PSU campus known as Electric Avenue.
Zimmerman’s interest is in what she calls, “the softer side of engineering”: working to find the best ways to provide power to communities, especially renewable power. One way Zimmerman is pursuing this interest is by collecting and analyzing data from the electric vehicle (EV) charging stations on the PSU campus known as Electric Avenue.
Zimmerman recently presented her initial findings at the first annual campus-wide research symposium.
Launched in August 2011, Electric Ave. is the result of a strategic partnership between PSU, PGE and the City of Portland. The seven chargers on site were donated by various manufacturers. PGE planned, designed and built the site. For Zimmerman, studying Electric Ave. is a research opportunity in which real-world data can be gathered, analyzed and reported. In conjunction with this project, Zimmerman and others will also build computer-based models wherein the performance of charging system components can be virtually tested.
According to Zimmerman, the charging circuits in EVs create harmonics in electrical distribution systems. Harmonics, she noted, in power systems are similar to harmonics in acoustics, but whereas harmonics in music create pleasant sounds, in electrical systems they result in discord and can damage electrical equipment moving power through the grid. Zimmerman wanted to know more about what effects harmonics generated by cars charging at Electric Ave. were having on the power grid.
"By June of 2012, Electric Ave. had supplied 18,000 kwh of renewable energy to EVs, equal to 54,000 miles of tailpipe-emissions-free electric driving."
With an award from the Maseeh College of Engineering and Computer Science’s Undergraduate Research & Mentoring Program, under the guidance of advisor Dr. Robert Bass and with the resources of the PGE Foundation Power Engineering Laboratory, Zimmerman set to work studying Electric Ave.
“Getting some hard data on non-linear loads was of special interest to me,” Zimmerman said. “The power electronics in EV charging circuits create loads that tend to be non-linear. This can cause issues such as high harmonic content and low power quality.
“Harmonic content can damage transformers and create discrepancies between power generated and power delivered. There are also issues with system imbalance and conductor heating.”
Zimmerman’s research aims to provide data necessary to mitigate the negative effects of harmonics in the system. Recently, Dr. Bass and Zimmerman were awarded a grant from PGE to fund continued research at Electric Ave. Going forward Zimmerman plans to quantify the negative effects of harmonics on the system and develop a series of recommendations to make for parties interested in installing similar charging stations here in the Metro region and beyond.
Zimmerman’s research, however, is not limited to calculating the negative effects on the grid of harmonics created by charging circuits on EVs. With funding from the Oregon Transportation Research and Education Consortium (OTREC), Zimmerman plans to develop computer models to test the circuitry of electrical components used to charge EVs. In the future, models such as these may help engineers designing charging circuits create better products that will put less stress on the grid.
“There are so many parties involved in these installations and not just at Electric Ave.,” Zimmerman said. “Without data on the effects EVs are going to have on the grid, there’s going to be some resistance to adopting this new infrastructure.
“We need research and development to support these kinds of changes, to show the companies that might design EV charging circuits or install charging stations that there is a way to get it done right without causing problems for the grid.”
For cities making an effort to reduce their carbon footprint and move toward more renewable energy, technologies like EVs and EV charging stations are a must. Developing the infrastructure for such a mammoth shift will take talented engineers dedicated to improving green technologies and championing their use. At this year’s campus-wide research symposium, Nicole Zimmerman made it clear that she is one of those engineers.
Authored by Shaun McGillis
Posted June 18, 2013