BYOE: A Flexible System for Visualizing Switching Regulator Operation

Harry Courtney Powell; Kay Hutchinson

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Conference: 2020 ASEE Virtual Annual Conference Content Access
Location: Virtual On line
Publication Date: June 22, 2020
Start Date: June 22, 2020
End Date: June 26, 2021
Conference Session: Experimentation and Laboratory-oriented Studies Division Technical Session 6
Tagged Division: Experimentation and Laboratory-Oriented Studies
Page Count: 12
DOI: 10.18260/1-2--34244
Permanent URL: https://peer.asee.org/34244
Download Count: 414

Paper Authors

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Harry Courtney Powell University of Virginia

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Harry Powell is a Professor of Electrical and Computer Engineering in the Charles L. Brown Department of Electrical and Computer Engineering at the University of Virginia. After receiving a Bachelor's Degree in Electrical Engineering in1978 he was an active research and design engineer, focusing on automation, embedded systems, remote control, and electronic/mechanical co-design techniques, holding 16 patents in these areas. Returning to academia, he earned a PhD in Electrical and Computer Engineering in 2011 at the University of Virginia. His current research interests include machine learning, embedded systems, electrical power systems, and engineering education.

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Kay Hutchinson University of Virginia

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Kay Hutchinson is an Electrical Engineering Ph.D. student at the University of Virginia. She obtained her Bachelor's Degree in Electrical Engineering from the University of Virginia in 2018 and joined the Dependable Systems and Analytics lab led by Professor Homa Alemzadeh. Kay Hutchinson's current research interests include surgical robotics, autonomous systems, and cyber-physical systems.

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Abstract

At the UXX we have experienced increased student interest in alternate and renewable energy topics in Electrical and Computer Engineering over the past 5 years. This has presented a challenge, as we currently only offer a single “Electromagnetic Energy Conversion” course, which is in a lecture format with a required associated laboratory section. To address this challenge, we have been systematically phasing out older topics, i.e., D.C. motors, and adding course content relevant to photovoltaics and wind energy production. This has necessitated a redesign of some of our laboratory experiences and required us to reconsider the most efficient way to transmit a breadth of understanding while giving students the opportunity to explore selected topics in greater detail. A fundamental building block of all photovoltaic and wind-based energy systems is the switching voltage regulator. This device enables changing system D.C. voltage levels with exceptionally high efficiencies, in many cases comparable to transformers for A.C. systems. This basic building block also appears in D.C. to A.C. conversion techniques for grid-connected devices. As a first step in updating our laboratory sequence, we elected to include material and experiments related to switching regulator design. We have examined, and employed in past classes, commercially available switching regulator evaluation boards, and while they are quite functional, they provide limited opportunity to explore the various parameters that determine the overall design, and how controlling each parameter individually may affect the overall performance of the system. To address these limitations, this BYOE paper describes an experimental apparatus that we designed that includes the two most common building blocks: the buck regulator, and the boost regulator. In our design, we incorporate inexpensive Hall-effect current sensors in all circuit branches, including the critical inductor and switch nodes. We also provide observability of the related node voltages. All of our signals are generated by an embedded computing device that drives a graphical user interface. This approach allows us to address several parameters that are typically not visible in commercial units. For example, the switching frequency is easily variable, allowing students to observe how this relates to concepts such as peak inductor current, peak switch current, ripple, and efficiency, all in real-time. We also allow the students to run the system in open loop mode to observe relationships between output voltage and duty cycle. A useful feature is the ability to use closed loop control, and to modify the feedback parameters in real time to study the effect on settling time and stability. In this paper, we describe our device, and give complete design information. We also show how it may be used in various classroom and laboratory settings and adapted to different levels of course material. We also include simulation information and show how the simulations may be compared with the experimental observations. All materials are open-source and the authors will supply complete design packets.

Citation
Format

Powell, H. C., & Hutchinson, K. (2020, June), BYOE: A Flexible System for Visualizing Switching Regulator Operation Paper presented at 2020 ASEE Virtual Annual Conference Content Access, Virtual On line . 10.18260/1-2--34244

TY - CPAPER
AB - At the UXX we have experienced increased student interest in alternate and renewable energy topics in Electrical and Computer Engineering over the past 5 years. This has presented a challenge, as we currently only offer a single “Electromagnetic Energy Conversion” course, which is in a lecture format with a required associated laboratory section. To address this challenge, we have been systematically phasing out older topics, i.e., D.C. motors, and adding course content relevant to photovoltaics and wind energy production. This has necessitated a redesign of some of our laboratory experiences and required us to reconsider the most efficient way to transmit a breadth of understanding while giving students the opportunity to explore selected topics in greater detail.
A fundamental building block of all photovoltaic and wind-based energy systems is the switching voltage regulator. This device enables changing system D.C. voltage levels with exceptionally high efficiencies, in many cases comparable to transformers for A.C. systems. This basic building block also appears in D.C. to A.C. conversion techniques for grid-connected devices. As a first step in updating our laboratory sequence, we elected to include material and experiments related to switching regulator design.
We have examined, and employed in past classes, commercially available switching regulator evaluation boards, and while they are quite functional, they provide limited opportunity to explore the various parameters that determine the overall design, and how controlling each parameter individually may affect the overall performance of the system. To address these limitations, this BYOE paper describes an experimental apparatus that we designed that includes the two most common building blocks: the buck regulator, and the boost regulator.
In our design, we incorporate inexpensive Hall-effect current sensors in all circuit branches, including the critical inductor and switch nodes. We also provide observability of the related node voltages. All of our signals are generated by an embedded computing device that drives a graphical user interface. This approach allows us to address several parameters that are typically not visible in commercial units. For example, the switching frequency is easily variable, allowing students to observe how this relates to concepts such as peak inductor current, peak switch current, ripple, and efficiency, all in real-time. We also allow the students to run the system in open loop mode to observe relationships between output voltage and duty cycle. A useful feature is the ability to use closed loop control, and to modify the feedback parameters in real time to study the effect on settling time and stability.
In this paper, we describe our device, and give complete design information. We also show how it may be used in various classroom and laboratory settings and adapted to different levels of course material. We also include simulation information and show how the simulations may be compared with the experimental observations. All materials are open-source and the authors will supply complete design packets.

AU - Harry Courtney Powell
AU - Kay Hutchinson
CY - Virtual On line
DA - 2020/06/22
PB - ASEE Conferences
TI - BYOE: A Flexible System for Visualizing Switching Regulator Operation
UR - https://peer.asee.org/34244
DO - 10.18260/1-2--34244
ER -