8

CEME Hands-On Undergraduate

Research Opportunities

Grainger Undergrad Research and Leadership Award

The Grainger CEME since its inception has supported undergrad researchers in the lab un-der the direction of graduate students working on particular projects, as members of team proj-ects, including the 2001 and 2004 Future Energy Challenge teams and the 2005-07 and 2007-09 Solar Decathlon teams, and through group projects of our collaborating universities. Several of these undergrads have continued their research to earn M.S. and Ph.D. degrees in power engi-neering. This last fiscal year undergraduate research has expanded exponentially—sixteen under-grads researchers worked in the lab during the spring semester, including three who were part of an independent study group, and twenty this summer. Three factors account for this growth. The first is the sheer number of graduate students—our group is larger than it has ever been—and more grad students are doing experimental work, thus requiring help from undergrads. The second is the Grainger Undergrad Research and Leadership Awards. Four undergrads selected for this award have done/are doing research in the lab. The third factor is a strong interest among undergraduates to learn through hands-on research. Students have begged their profes-sors for the opportunity, in addition to their senior design projects, to work in the lab. Some have volunteered, and one applied a University of Illinois summer internship to the CEME lab.

What have these undergrad researchers accomplished? They have assisted graduate students with indirect field-oriented motor control research, simulation and implementation of nonlinear control techniques for induction motors, induction motor parameterization and data collection and testing, and helped load and test two new modular inverters. They helped with research on input-series output-parallel interleaved uneven switching supplies, real-time low-level simulation of hybrid vehicle systems, solar panel maximum power point tracking, hydrogen fuel-cell sys-tems for the Army Corps of Engineers at the Construction Engineering Research Laboratory in Champaign; and installed solar panels on the roof of Everitt Laboratory. In short, they have been/are indispensible to research for the CEME.

What has been the undergraduate assistants’ take on these research activities? Two shared their experience. Samantha Gunter won a Grainger Undergrad Research and Leadership Award and Harikrishna Rao worked with several other undergrads on the Everitt Solar Panels project. Both graduated and are furthering their studies in power engineering in graduate school.

Samantha wrote,

“Upon receiving the CEME Research and Leadership Scholarship, I was given the ability to work with the current graduate students on research relating to power engineering. My time was split between working with the Army Corps of Engineers and with a graduate student working on power electronics. At the Construction Engineering Research Laboratory in Champaign, I was exposed to fuel cell systems. It was fascinating to see new technology in a practical application and learn more about the systems. In addition, we were able to showcase a fuel cell during Engineering Open House and spread more knowledge to the public as well as give them a chance to view the technology. That was the first time I ever participated in Engineering Open House and it was a wonderful experience. The second half of my time was spent trying to build a dc-dc converter for a graduate student’s master’s thesis. This gave me the opportunity to use what I learned in class and apply it to a real-life engineering problem. Theoretical calculations to actually build components from scratch were done in order to

9

complete the circuitry. The work on the converter exposed me to what it is really like to do research in a lab which would certainly prepare me for my future endeavors.

“The CEME Research and Leadership Scholarship opened many doors for me and gave me the ability to do things that I would not have been able to do otherwise. After obtaining the scholarship, I was able to get to know some of the best and most respected professors in power engineering and to obtain valuable experiences relating to research. I believe this is the main reason why I was accepted into graduate school and why I am currently attending the Massachusetts Institute of Technology. Without the generosity of Grainger, I firmly believe I would not have been able to take this path and pursue further research into power and energy systems.”

The Everitt Solar Panels project is the single project employing the most undergrads. The project description and Harikrishna Rao’s experience follow.

Everitt Solar Panels Project

The Everitt Solar Panel project objective is to construct a 1.5 kW photovoltaic (PV) test bed for performing power electronics and power systems research. The initial work was conducted over the 2008 fall semester by graduate student, Grant Pitel, and three undergraduate assistants,

Mike Driscoll, Harikrishna Rau, and Taylor Wu, who were interested in being a part of a renewable energy project (Figure 1). Two of the undergraduate assistants formed the core of the 2009 spring semester group. Eight British Petro-leum (BP)7185N solar panels reused from the University of Illinois entry in the 2007 Solar Decathlon [www.solardecath-lon.uiuc.edu] have been installed. The solar panel array is secured on the roof of Everitt Lab facing due south (Figure 2), and angled for optimal winter collection (Urbana latitude 40.11 degrees × 0.9 + 29 degrees = 65.1 degrees). Each BP solar panel is rated at a peak power of 185 Watts, 36 V dc, 5.14 A, and measures 2.6 ft × 5.2 ft × 2 in. The open-circuit voltage is 44.2 V and short-circuit current 5.44 A. Each has

an 8 A minimum bypass diode and a 15 A maximum series fuse.

The solar panels will deliver their combined dc power to the Everitt Laboratory third-floor Advanced Power Ap-plications Lab, into a CEME-designed modular-inverter dc bus. The inverter is used to turn the dc voltage of the solar panels into the ac voltage of the US power grid. The PV panels are configured in series to produce 288 V dc open circuit (Figure 3). The CEME modular-inverter power switches can be installed as a MOSFET (400 V at 10 A rms) or IGBT (400 V at 40 A rms). Power into the grid can be monitored in two ways: through a GUI (graphical user

interface) pro-grammed at the University that monitors and controls phase angle, frequency, bus voltage, phase current, and control effort. A digital power meter is also connected for

Figure 1 Grant Pitel (far right) and three undergraduate

assistants: Harikrishna Rau, Taylor Wu, and Mike

Driscoll.

Figure 2 Solar panel array secured on the roof of Everitt

Lab.

Figure 3 PV panel-inverter-bus configuration.

INVERTER

B2

ACBUS

120AC

PVBUS

B1

288 VDC

S5F1

15A

U4

PV PANELS

S3

T1R2

100 Ω

S4

T2