Engineering Commons^™

Dc-Dc Buck Boost Converter Using The Lt8390 Controller And Gan High Electron Mobility Transistors, Juan Manuel Urbano Jr, Brian Thongchai Keokot

Electrical Engineering

California Polytechnic State University, San Luis Obispo’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project creates a sustainable energy source by converting physical exercise from exercise machines into renewable electricity. Implementing energy harvesting technology into the Recreation Center’s exercise machines helps Cal Poly make progress on its goal of carbon neutrality by 2050 [1]. An improvement to the system with new technology increases Cal Poly Recreation Center’s ability to save money and improve sustainability.

The focus of this project improves the design of Nicholas Serres, who used the LT8390 controller in his buck boost DC-DC converter [2]. This project improves …

Dc-Dc Buck-Boost Converter For Energy Harvesting From Exercise Equipment, David T. Bolla

Electrical Engineering

This senior project helps harvest the excess energy that exercise equipment generates. Sustainable energy acts as the main target for this project, and it attempts this through reusing the energy created when exercising on elliptical machines. An elliptical machine outputs voltages between approximately 5V and 60V, and a micro-inverter requires an input voltage of about 36V. This DC-DC converter takes the variable output voltage of an elliptical machine and brings it to approximately 36V. Re-purposing the excess energy an elliptical user creates for the grid provides a sustainable alternative to dissipating the energy as heat. This project, along with other …

Dc-Dc Converter Control System For The Energy Harvesting From Exercise Machines System, Alexander Sireci

Master's Theses

Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states.

An artificial neural …

Energy Harvesting From Exercise Machines: Comparative Study Of Ehfem Performance With Dc-Dc Converters And Dissipative Overvoltage Protection Circuit, Cameron Kiddoo

Master's Theses

Energy Harvesting from Exercise Machines (EHFEM) is an ongoing project pursuing alternate forms of sustainable energy for Cal Poly State University. The EHFEM project seeks to acquire user-generated DC power from exercise machines and sell that energy back to the local grid as AC power. The end goal of the EHFEM project aims to integrate a final design with existing elliptical fitness trainers for student and faculty use in Cal Poly’s Recreational Center. This report examines whether including the DC-DC converter in the EHFEM setup produces AC power to the electric grid more efficiently and consistently than an EHFEM system …

Energy Harvesting From Exercise Machines: Buck-Boost Converter Design, Andrew E. Forster

Master's Theses

This report details the design and implementation of a switching DC-DC converter for use in the Energy Harvesting From Exercise Machines (EHFEM) project. It uses a four-switch, buck-boost topology to regulate the wide, 5-60 V output of an elliptical machine to 36 V, suitable as input for a microinverter to reclaim the energy for the electrical grid. Successful implementation reduces heat emissions from electrical energy originally wasted as heat, and facilitates a financial and environmental benefit from reduced net energy consumption.

Dc-Dc Converter Input Protection System For The Energy Harvesting From Exercise Machines (Ehfem) Project, Ryan Turner, Zack Weiler

Electrical Engineering

The ongoing Energy Harvesting from Exercise Machines (EHFEM) project at Cal Poly San Luis Obispo seeks to provide renewable energy without the high cost of implementation by harvesting DC power generated on machines used for physical exercise. The EHFEM project consists of numerous subprojects that involve converting different types of exercise machines for power generation. This project specifically works by scaling the output voltage from an elliptical machine using a DC-DC converter and sending it through an Enphase Micro-inverter to feed AC power back to the power grid and minimize energy spending. As a subset of the much larger project, …

Exercise Bicycle Dc-Dc Converter For The Energy Harvesting From Exercise Machines Project, Ryan Rickard, Logan Stowe

Electrical Engineering

Project is a continuation of previous projects that seek an efficient DC to DC converter for the existing exercise bicycle system created by Mechanical and Electrical Engineering students. This DC-DC converter is to integrate with the wide range of DC voltages produced by the bicycle in order to produce a constant optimal voltage for charging a car battery. This converter will boost voltages when the bicycle outputs below the optimal voltage and buck voltages when above. The converter will take EHFEM one step closer to its overall and final goal of harvesting energy from the exercise machines in Cal Poly’s …

Elliptical Machine Dc-Dc Converter For The Energy Harvesting From Exercise Machines Project, Greg Hollister

Electrical Engineering

Designing a DC/DC Converter for the Cal Poly Energy Harvesting from Exercise Machines project requires special attention to the unique operating characteristics of the source and the load. An elliptical machine powered by a person exercising comprises the source, while an AC Inverter makes up the load. This project attempts to integrate the two devices with a custom DC/DC Converter in order to ultimately deliver power back into the power grid.

Energy Harvesting From Elliptical Machines Using Four-Switch Buck-Boost Topology, Alvin Jay Hilario

Master's Theses

This thesis presents the topic of using the Four-Switch Buck-Boost topology as a DC-DC converter for the Energy Harvesting from Elliptical Machines Project. The project works toward providing a modular synchronous power generation system. Due to the dynamic and sporadic output voltage and power characteristics of the Precor elliptical machine, the system requires a DC-DC converter as a voltage preregulator. The inherent wide input range, high efficiency, and low parts cost of this converter well suit the application. This paper further discusses other topologies and their shortcomings, as well as characterizes the Precor elliptical machine and Enphase Microinverter for interfacing. …

Energy Harvesting From Exercise Machines Cal Poly Recreation Center Implementation, Justin Arakaki, Praveen Lawrence, Audrey Nakamura

Electrical Engineering

As Cal Poly moves towards an environmentally friendly campus, the Energy Harvesting from Exercise Machines (EHFEM) project looks to generate a new source of renewable energy to help power the Cal Poly Recreation Center. The project focuses on retrofitting exercise machines to generate electricity. As of December 2009, Audrey Nakamura, Justin Arakaki, and Praveen Lawrence developed a design which allows the contribution of electricity generated from multiple exercise machines into the power grid.

The project will require an investigation of retrofitted machine designs by Cal Poly students and commercially available products and systems. The information obtained from the product research …

Energy Harvesting From Exercise Machines: Bike Buck-Boost Converter, Monroe Diamond, Brian Vuong

Electrical Engineering

This project is a continuation of previous senior projects’ work on Energy Harvesting from Exercise Machines (EHFEM). EHFEM seeks an alternative DC to DC converter to function within the existing exercise bike system. Implementing this new DC to DC converter aims to avoid previous complications other groups encountered, such as only running at low load currents, exceeding an input threshold voltage to begin operation, and performing at low efficiency. In developing this self‐generating exercise bike, Cal Poly wishes to incorporate an array of energy‐harvesting exercise machines in its Recreation Center expansion scheduled for completion in 2012.

Exercise Power Grid Display And Web Interface, Alexander (Alex) Chernetz

Computer Engineering

The 2008-2009 expansion of the Recreation Center at Cal Poly includes three new rooms with cardiovascular fitness equipment. As part of its ongoing commitment to sustainable development, the new machines connect to the main power grid and generate power during a workout. This document explains the process of quantifying and expressing the power generated using two interfaces: an autonomous display designed for a television with a text size and amount of detail adaptable to multiple television sizes and viewing distances, and an interactive, more detailed Web interface accessible with any Java-capable computer system or browser.