Engineering Commons^™

Dc-To-Dc Buck Converter, Kyle Christopher Roman

Electrical Engineering

The growth of sustainable energy requires many components to work in harmony creating one efficient and effective system. Sustainable energy generation that produces a DC current varying in voltage requires a subsystem to convert voltage to a practical and usable value. The DC to DC Buck converter converts high DC solar generated voltage to a 12V output. This Modular -Level power electronic (MLPE) device performs as a solar charge controller for small lithium ion batteries. Fluctuating voltage levels generated by Photovoltaic cells makes the solar controller a critical part of the solar system. Regulating the DC voltage allows safe and …

Flexible Custom Electric Skateboard, Caleb Adam Kelsay

Electrical Engineering

At Cal Poly traveling long distances only accessible by foot such as across campus or from the car park to class can be tiring and time-consuming. While not physically demanding, the trek consumes time in our tight college life schedule. To improve our time efficiency this project provides a relatively lightweight, powered solution to quickly and effectively travel long distances while maintaining full control and safety even on hills, a current limitation of traditional skateboards.

This electric skateboard includes the battery capacity to travel all around campus on a single charge with a compact and flexible skateboard design that provides …

Solar Powered Single-Axis Heliostat Active Solar Tracking Device, Mason Kyle Roberts

Physics

As a means of cooking food, the burning of biomass accounts for over 4 million premature deaths in third world countries (“Household Air Pollution and Health”). The focus of this project was to explore an alternative that could utilize focused sunlight to cook food. A solar tracker was designed to be affixed to a parabolic, reflective, tilted single axis heliostat to follow the sun throughout the day and focus the reflected light to the bottom of a cooking surface. This surface became hot enough to for the preparation of food or boiling/sterilization of water.

A goal for each project was …

Mini High Temperature Test Unit Final Design Report, Kevin Liu, Juan P. Castillo

Mechanical Engineering

Lawrence Livermore National Laboratory has invested considerable effort to develop new standard for nuclear grade HEPA filters that can withstand high temperatures along with methods to optimally test not only the experimental filter media, but also new frame seals and media binders. Therefore, LLNL in collaboration with Cal Poly has designed and built a Mini High Temperature Testing Unit (MHTTU) to recreate conditions observed during a fire and to test different materials in an effective, inexpensive, regulated and reliable method. The existing prototype was unable to achieve the ideal testing conditions of 1000°F air at the low flow rates of …

Marine Gastrobot Final Design Report, Wesley B. Williams, Eric Kane Dreischerf, Tommy Nicholas Yath

Mechanical Engineering

The Marine Gastrobot sponsored by Dr. Christopher Kitts of the Cal Poly Center for Applications in Biotechnology was a research and development effort intended to explore the use of microbial fuel cell technology as a power source for underwater robots. Our team Ocean Locomotion succeeded in developing a first iteration of an underwater robotic platform suitable for microbial fuel cell integration. The primary feature of the design is its sinusoidal fin propulsion intended for benthic exploration with limited risk of entanglement. During the course of development, Ocean Locomotion explored the use of low power actuation methods and determined their limited …

Design And Construction Of 1800w Modular Multiple Input Single Output Non-Isolated Dc-Dc Converters, Angelo Miguel Asuncion Gallardo

Master's Theses

This thesis report details the design and construction of non-isolated DC-DC converters to create a Multiple Input Single Output (MISO) converter for combining multiple renewable energy sources into one single output. This MISO uses the four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The MISO converter implements a modular approach to deliver 1800W output power. Each module in the MISO is rated at 600W and they share the output power equally. Hardware results show that the converter produces 1800W of output power from three sources with 96.4% efficiency. Each module also demonstrates equal sharing feature …

Lab-Scale Circuit Breaker Module For Power System Laboratories, Amanda Barley, Allen C. Scozzari, Joshua E. Chung

Electrical Engineering

In this project, a circuit breaker that can simulate different types of power system faults is redesigned, constructed, and tested. They will then be implemented in power systems laboratory courses at Cal Poly. The project’s goal is to improve a previous circuit breaker design to help students better visualize how faults affect power systems in the real world. Two main improvements are made to the previous circuit breaker design. The first improvement is to power the breaker with a typical wall outlet adapter instead of the DC source from the Cal Poly power systems laboratory test benches. This lets the …

Hybrid Water Pump, Dylan W. Grant, Wei Chen Yeh

Electrical Engineering

This project seeks to use multiple sources to power a water pump. We will design a system which will combine inputs from solar and wind energy production to ensure the pump will have enough power to run. This will create a system powered by clean energy and will be self-sustained once completed. This will theoretically create a more sustainable source of power for the pump than only one of the sources. Because the power sources don’t require outside inputs (aside from sun and wind), the pump can be placed in a remote area. This could be very helpful in developing …

Automatic Standby Power-Saving Power Strip, Trung Nguyen

Electrical Engineering

The Standby Power Saving Power Strip improves on common power strip functionality. The project reduces the power loss from most electrical devices’ standby power mode, while retaining the convenience of leaving the devices plugged-in. The surge protector automatically recognizes when the plugged-in devices enter standby power mode. Then, it shuts off power to that device and automatically provides power back to the plugged-in devices, when turned on.

Solar Roller - Solar Powered Usb Charging Station, Aaron Bartfeld, Tanner Mjelde, Kaylan Naicker

Electrical Engineering

As the necessity for renewable energy increases, solar power becomes more and more prevalent. At the same time, as technology increases, the necessity for charging one’s electronic devices also increases. The Solar Roller merges solar energy with the ability to charge one's electronic device in one compact cart. The Solar Roller is a solar-powered USB charging station that allows people of all backgrounds to develop a better understanding of alternative fuels, while charging their USB device. It has a touch screen display that provides voltage levels of the battery as well as a TV that displays solar powered information. The …

Microgrid Protection Student Laboratory, Ian Hellman-Wylie, Joey Navarro

Electrical Engineering

To better prepare students for careers in the electric power industry, specifically in the discipline of power system protection, the Electrical Engineering Department at Cal Poly San Luis Obispo proposed an initiative calling for the creation of new laboratory curriculum that uses microprocessor-based relays to give students hands-on experience in the application of protection theory. This report describes the creation of a system that meets this need by providing a laboratory-scale power system that demonstrates the use of common protective relays and protection schemes. This system provides a platform for laboratory coursework using protective relays for transmission line, transformer, and …

Dual Input Microinverter For Tandem Cells, Forrest M. Lipske, Daniel A. Dich-Dang

Electrical Engineering

For every solar panel, there is an inverter which transforms the harvested DC electricity into AC electricity so that it can connect to the grid and power household appliances. In this project, we examined a tandem solar cell being designed by Iris Photovoltaics which has two layers with two distinct outputs, and we explored several solutions to create a microinverter which can handle dual inputs from the tandem PV and combine them into a single AC output. To examine the viability of such a microinverter, we designed and simulated the DC-DC combination portion of the specialized dual input microinverter, resulting …

Light Sensing Automated Blinds, Andrew B. Hodges, Ryan C. Flick

Electrical Engineering

This project is solving the problem of wasted energy within buildings and homes, because currently the lights turned on inside building do not utilize natural, ambient light from the sun. Rather than having unnecessary light from a light source, the automated light sensing smart blinds can sense the amount of light outside the window and in the room, and then adjust the angle of the blinds to save energy by utilizing the available outdoor light. This way, the light source will not be running at maximum power output while there is excess light coming through the window. This project aims …

Student Experimental Farm Smart Pathway Lighting System, Emily A. Whitaker, Vineal S. Singh, Edith Rodriguez

Electrical Engineering

This project works together with the Student Experimental Farm (SEF) and the DC House in order to install a smart lighting pathway system. This system will run off of DC power supplied by the solar panels connected to the DC House. This project tested and explored the group’s abilities to design and implement a full system run off of 48V DC. By installing this system it will greatly improve the ease for students to work at the SEF beyond daylight hours. The system will allow continuous dull lighting and will switch to full brightness once a person is detected. This …

Dc House Energy Management System, Zachary L. Eldredge, Zoe M. Hay

Electrical Engineering

In this work, a previously completed proof of concept for an Energy Management System (EMS) for the DC House project has been revised and re-implemented. The implemented design changes will improve the performance and reproducibility of the system. This new design of the EMS replaces the two-separate buck and boost DC-DC converters with a single bidirectional DC-DC converter to reduce components and improve efficiency. Analysis of the bidirectional DC-DC converter shows high efficiency especially at larger load currents. The code of the previous work was updated for smoother operation as well as to accommodate an LCD capable of displaying more …

Solar Powered Electric Vehicle Charger, Jessica A. Bombardier Shaw, Andrew F. Moradpour

Electrical Engineering

This project will look into how to create an efficiently-operated solar powered electric vehicle charger. The solar panel will harvest energy from the sun that will be stored a battery pack to be readily available to charge an electric vehicle. These stations could be commercialized to be located along a highway, or personalized for a in-house installation.

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 …

A Modified Boost Converter With Reduced Input Current Ripple, Nathan H. Lentz

Master's Theses

Battery-powered trends in consumer electronics, transportation, and renewable energy sectors increase demands on DC/DC converter technology. Higher switching frequency and efficiency reduces solution size and cost, while increasing power capabilities. Still, switching noise remains the primary drawback associated with any DC/DC converter. Reducing a converter’s input ripple helps prevent switching noise from spreading to other systems on a shared DC power bus. This thesis covers the analysis, simulation, and implementation of a recently-proposed boost converter topology, alongside an equivalent standard boost converter, operating in steady-state, continuous conduction mode. A Matlab-based simulation predicts each converter’s input ripple performance using a state-space …

Protective Relaying Student Laboratory, Kenan W. Pretzer

Master's Theses

Facing a rapidly-changing power industry, the electrical engineering department at Cal Poly San Luis Obispo proposed Advanced Power Systems Initiatives to better prepare its students for entering the power industry. These initiatives call for the creation of a new laboratory curriculum that uses microprocessor-based relays to reinforce the fundamental concepts of power system protection. This paper summarizes a laboratory system fit for this task and presents a set of proposed laboratory experiments to establish a new laboratory course at Cal Poly. The experiments expose students to the capabilities of industry-standard microprocessor-based relays through hands-on procedures that demonstrate common power system …

Wireless Charging For Bluetooth Earphones, Daniel Carlson

Electrical Engineering

This project involves designing and building an inductive charging system for Bluetooth earphones. This system provides a charging dock for a pair of retrofitted Bluetooth earphones and focuses on ease-of-use and convenience for the user. The motivations for this project include providing charging compatibility to changing audio technology and trends. Smart phones and other audio products are increasingly leaning towards wireless (Bluetooth) audio, and wireless headphones/headsets are naturally becoming more prevalent to match this trend. A small, easy to use, and efficient charging dock for these earphones seems like a necessary accessory for this technology to seem attractive to consumers. …

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 …

Off Grid Solar Array, Courtney Elliott

Electrical Engineering

No abstract provided.

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.

Energy Management System Modeling Of Dc Data Center With Hybrid Energy Sources Using Neural Network, Khalid Althomali

Master's Theses

As data centers continue to grow rapidly, engineers will face the greater challenge in finding ways to minimize the cost of powering data centers while improving their reliability. The continuing growth of renewable energy sources such as photovoltaics (PV) system presents an opportunity to reduce the long-term energy cost of data centers and to enhance reliability when used with utility AC power and energy storage. However, the inter-temporal and the intermittency nature of solar energy makes it necessary for the proper coordination and management of these energy sources.

This thesis proposes an energy management system in DC data center using …

Comparison Of Ac And Dc Led Light Bulb Efficiency For The Dc House Project, Brandon Stafford

Electrical Engineering

This project investigates the efficiency of using LED light bulbs when operated under two different electrical systems: AC and DC systems. The project is in conjunction with the implementation of the DC House system in urban areas. More specifically, this project looks at whether having a hybrid AC and DC system in a typical urban house will increase the efficiency in operating the LED light bulbs, and thus reducing energy consumption and cost. The efficiency of the LED light bulbs are measured by looking at their lumens per watt output. Several light bulbs at four different wattage levels were tested. …

A Method For Evaluating Aircraft Electric Power System Sizing And Failure Resiliency, Cory Kenneth Kross

Master's Theses

With the More Electric Aircraft paradigm, commercial commuter aircraft are increasing the size and complexity of electrical power systems by increasing the number of electrical loads. With this increase in complexity comes a need to analyze electrical power systems using new tools. The Hybrid Power System Optimizer (HyPSO) developed by Airbus SAS is a simulator designed to analyze new aircraft power systems. This thesis project will first provide a method to assess the reliability of complex aircraft electrical power systems before and after failure and reconfiguration events. Next, an add-on to HyPSO is developed to integrate the previously developed reliability …