Engineering Commons^™

Skip The Grid: Giving Power To Navajo Nation, Ryan J. Schacherbauer

Construction Management

Skip the Grid is a project organized by Heart of America, a nonprofit, looking to improve the education and overall wellbeing of children and their families. Many residents within Navajo Nation do not have access to continuous power and rely on temporary generators or car battery to obtain any kind of electricity. Heart of America partnered with the Red Mesa School District to identify families that did not have power, which was impacting the children’s ability to complete their online schoolwork. This senior project was comprised of an interdisciplinary team responsible for installing a working solar system on twelve homes …

Smart Usb-C Wall Plug For The Dc House Project, Ridge Lahti, Dino Maslic

Electrical Engineering

DC operated devices and appliances powered by AC systems suffer inefficiencies resulting from the losses of converting AC energy into DC energy. At Cal Poly, the DC House Project aims to minimize the need for AC electricity in homes and encourage the use of renewable energy systems. The DC House uses a 48V DC bus that must be stepped down for use with increasing number of DC loads in a typical home. In this project, a Smart USB-C Wall Plug is designed to work with USB Power Delivery to provide a variable voltage output for use with these DC loads …

Controlling Temperature Of Dc-Dc Converter Using Switching Frequency Adjustment, Sajjad Ahsan, Arsalan Mughal, Mark Rapiz

Electrical Engineering

As DC-DC converter operates under different load conditions, the amount of loss within the converter varies accordingly. Consequently the temperature of the DC-DC converter will also change based on the load demand. For PWM based DC-DC converters, one factor that contributes to the loss; thus, the increase in temperature is the switching frequency at which the converter operates. The higher the switching frequency used, the bigger the switching loss and in turn the hotter the converter. In this project, the temperature of a DC-DC converter is controlled by changing the switching frequency used by the converter. The hardware investigation used …

Hybrid Ac/Dc House: The Road To A Sustainable Future, Nicholas Mcadams, Luis Rodriguez

Electrical Engineering

The Hybrid AC/DC house is a sustainable alternative to preexisting residential power systems. The implementation of a DC bus in current homes will allow inefficient DC-AC and AC-DC conversions to be circumvented. This provides a direct path for current to flow to DC loads from DC sources such as solar panels to minimize power losses. In doing so, this will give users the ability to power their homes strictly from renewable sources and substantially decrease reliance on the utility. For this purpose, the hybrid AC/DC house is also designed in such a way to be entirely grid-independent to provide power …

Microgrid Laboratory Wind Energy Integration, Vincent Liang

Master's Theses

Cal Poly San Luis Obispo’s Electrical Engineering Department and the Power Energy Institute have developed a microgrid laboratory with various generators, loads, and protection systems over the past several years. To improve and make the Cal Poly microgrid laboratory more realistic, this thesis outlines the process of improving the EE microgrid setup by adding a wind energy generation system via an induction generator, excitation capacitors, and a protection relay. By adding an induction generator, the microgrid system becomes more resilient to sudden power fluctuations by maintaining a stable voltage and frequency when the microgrid is islanded. To test this, a …

Current-Source Dc-Dc Converter For Fiber-Optic Communication Systems, Jissell C. Jose

Master's Theses

In this thesis, a proof of concept for a current-source DC-DC converter for powering sensors used in an underwater communications system is presented. The proposed converter steps down an input current of 0.9 A to 0.625 A, while maintaining an output voltage of 24 V and output power of 15 W. The complete steady-state analysis and design of the proposed converter in its single-stage form is also explained in detail. Performance evaluation of the proposed converter was carried out using LTspice. Results of the simulation demonstrate that the design was able to produce average output current of 0.639 A at …

Installation Of Electrical System For Paso Robles Police Department, Peter D. Strykers, Jacob M. Studebaker

Construction Management

This paper outlines the process that Peter Strykers and Jacob Studebaker went through to set up the lighting and power system for the Paso Robles Police Department gun range located off highway 46. Before our installation, the gun range had zero lighting so the officers could not use it after sunset. We allowed the officers to light the gun range with outdoor LED lights, light up both the storage units on site, and have access to multiple outlets inside and out of the storage units. The power source that the electrical system runs on comes from a Kubota generator because …

Load Slammer Design For Dc-Dc Converter Testing, Jonathan Hidalgo, Quinton Lacomb

Electrical Engineering

In this work, we dive into the detailed design of a test load or load slammer circuit for DC/DC converters to ensure their correct functioning. This is accomplished through quick variations in frequency, amplitude, and duty cycle of the current being drawn by the converter into the load. Computer simulations of the design were performed using LTSpice and the results show that the load current could be varied per design objectives. Hardware implementation of the design was also conducted and then tested. Results were then compared with the design requirements at lower currents to evaluate the validity of the design. …

Ac/Dc Led Light Bulb Adaptor With Internal Rechargeable Batteries, Esteban A. Rubio, Matthew R. Delaby

Electrical Engineering

To make a sustainable product and provide a temporary source of lights on during emergencies, this project aims to create a small unit that can be attached to a light bulb of any variety and connect it to a socket. Within the device is a rechargeable battery that, when the device is not connected to an 120V AC, 240V AC, or 48V DC power source, will power the light for a short period of time. The battery can be charged during the standard operation of the device and can be powered by the US and EU standard outlet voltages as …

Performance Loss Rate And Temperature Modeling In Predictive Energy Yield Programs For Utility-Scale Solar Power Plants, Katelynn M. Dinius

Master's Theses

The Gold Tree Solar Farm, designed by REC Solar, has a rated output power of 4.5 MW and began operation in 2018 to provide electricity to Cal Poly’s campus. Gold Tree Solar Farm site terrain consists of rolling hills and uneven slopes. The uneven typography results in interrow shading, requiring a modified tracking control algorithm to maximize power production. Predicting a utility solar field’s lifetime energy yield is a critical step in assessing project feasibility and calculating project revenue. The MATLAB-based predictive power model developed for this field overpredicted power in the middle of the day. The purpose of this …

Solar Pv Emulator, Tristan Studer, Cody Kremer

Electrical Engineering

The implementation of a solar PV emulator. Creating a controllable testing environment which sufficiently recreates realistic conditions a photovoltaic cell would experience in real world use. The project aims to accurately show the efficiency and reliability of a solar PV cell, opposed to an ideal model which creates unrealistic expectations. The PV emulator implements conditions such as: irradiance, soiling and temperate changes. It gives feedback on a displayed IV curve and/or PV curve so the user may graphically analyze the output their PV cell produces given various conditions. It allows the user selectable conditions the solar cell may experience this …

Power Line Coupling Power Supply Design, Janine Gian Christii C. Darato, Jeni K. Kawate, Nicholas A. Marta

Electrical Engineering

In this project, a power supply was designed for a startup company, Perch Sensing, to detect wildfires with the use of distributed sensors across power lines. The purpose of the power supply is to provide 15W of power to a microcontroller, which controls the sensor nodes. The power supply hangs from power lines and draws energy by inductively coupling to these lines. Our design starts with a current transformer that steps down the current from the power line, which is fed into a shunting mechanism as a safety precaution when the load is absent, then to the power supply itself. …

Solar Photovoltaic Iv Curve Tracer, Jonathan W. Skelly

Electrical Engineering

The Solar Photovoltaic Current-Voltage (IV) Curve Tracer, sponsored by Cal Poly Professor Dale Dolan, characterizes solar array current vs. voltage curves for any given temperature and irradiance. The curve tracer is battery powered, and functions autonomously across loading conditions from short circuit to open load on any sub-450-watt solar array. The curve tracer supports separate data logging modes for both single cells and single modules to maximize data accuracy for each. For testing full strings of solar panels, up to 10 IV curves may be stored in persistent EEPROM memory. Stored data may be recalled later for output to a …

Miniaturized Ultraviolet Imager High Voltage Power Supply, Nicholas Palmer, Jason Thomas Heil

Electrical Engineering

Sending satellites into orbit becomes exponentially more expensive with weight and size, so designing high-voltage DC-DC converters that can achieve kilovolt level outputs in a small form factor is crucial to reducing costs. The Miniaturized Ultraviolet Imager (MUVI) aims to monitor Earth’s ionosphere and report weather patterns to climate scientists within a 2U cube satellite footprint. The imaging equipment consists of a microchannel plate and phosphor screen that require 2.5kV and 5.5kV respectively at microamp level currents. This report explains the implementation of a high voltage boost cascaded flyback converter to meet all of the MUVI satellite output voltage requirements. …

Buck Converter With Voltage Foldback Protection, Fabian Aaron Enriquez, Pedro Rincon Rosales

Electrical Engineering

In this work, we implemented the idea of current foldback protection onto a buck converter. Current foldback protection essentially helps reduce the power dissipation which may be caused by a short circuit or overload scenario. To achieve the goal of this project, we used a combination of comparators, operational amplifiers and MOSFETs to create a current foldback sub controller. This controller would then serve as a feedback device between the output of the converter and the main controller to detect if a fault condition has occurred. Following the design, we performed simulation of the current foldback controller using PSpice and …

Hybrid Ac/Dc House, Vinh Q. Tran, Casey Winans, Erin O'Rourke

Electrical Engineering

The Hybrid AC/DC house is a proof of concept implementing a DC bus in residential power systems. The implementation of the DC bus is motivated by efficiency through a direct path for DC sources and loads. The avoidance of DC-to-AC and AC-to-DC conversions used in typical residential systems especially those with DC sources such as solar panels could experience higher efficiencies through only DC-to-DC conversions between the sources and the loads.

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 …

Wildfire Early Detection System (Weds), Mason Mciver, Vincent Liang, Jeanreno Racines

Electrical Engineering

With climate change causing an increase in temperature over the past several decades, wildfires have been burning hotter and moving quicker leaving a trail of destruction in their path. Detecting a wildfire early allows firefighters to respond efficiently and effectively to ensure containment. With the rise of advanced computer vision and algorithms, autonomous systems can be used to monitor and report any fire activity. Having multiple devices spread out across a large area will allow first responders to map out the fire location and track the fire. By utilizing smart technologies, property damage can be minimized and residents living in …

Optimization Of Single Axis Tracker Settings In The Cal Poly Goldtree Solar Farm, Charles A. Studdard, Liliana Reyes

Electrical Engineering

Solar farms use direct sunlight when operating; additionally, solar modules produce the most energy aligned perpendicular to the sun. Single axis solar tracking systems allow the rotation tilted photovoltaic panels to rotate during the day, maintaining the panels at the utmost efficiency angle. Achieving maximum power generation and reducing shade on the panels, make it crucial to have constant optimum positioning. Larger farms contain multiple rows and columns leading the panels to cast shadows on one another. Backtracking happens when you eliminate or reduce shadow casted on panels from adjacent modules. Panels positioned equidistantly and on even terrain allows backtracking …

2021 Department Of Energy Collegiate Wind Competition Electrical System, Grayson Capers, Shane Alayvilla, Justin Rodrigues

Electrical Engineering

In this work, the implementation of the electrical system for Cal Poly’s 2021 Department of Energy Collegiate Wind Competition turbine is described. The mission of this project was to complete the turbine testing tasks to the best of the team’s ability. This system includes an off the shelf slotless permanent magnet synchronous generator and rectifier to produce a DC voltage. To maximize the power output at below-rated wind speeds, current sensors, voltage sensors, and a dynamic load with variable resistance were designed and tested. To curtail the power and rotor speed in high wind events, the turbine was equipped with …

Zero Voltage Switching Hybrid Voltage Divider Converter, Timothy Jeong

Master's Theses

This project proposes a new hybrid voltage divider DC-DC converter that utilizes switching capacitors and inductors to produce zero voltage switching (ZVS) at the turn on state of its switches. By achieving ZVS, the switching losses are significantly reduced; thus, increasing the overall efficiency of the converter at various loads. The goal for this thesis is to perform analysis of the operation of the converter, derive equations for sizing the main components, and demonstrate its functionality through computer simulation and hardware prototype. Results of the simulation and hardware testing show that the proposed converter produces the desired output voltage while …

Automation, Annunciation, And Emergency Safety Shutdown Of A Laboratory Microgrid Using A Real-Time Automation Controller (Rtac), Do Vo

Master's Theses

Over the last decade, microgrid deployments throughout the world have increased. In 2019, a record number of 546 microgrids were installed in the United States [1]. This trend continues upward to combat extreme weather conditions and power shortages throughout the country. To better equip students with the necessary skillsets and knowledge to advance in the microgrid field, Cal Poly San Luis Obispo's Electrical Engineering Department and the Power Energy Institute have invested resources to develop a laboratory microgrid.

This thesis sets to improve the laboratory microgrid's existing automation using the Schweitzer Engineering Laboratory SEL-3530 Real-time Automation Controller (RTAC). The improved …

Solar Soiling Mitigation, Claire Desmith

Electrical Engineering

This senior project aims to mitigate performance losses that occur in Photovoltaic (PV) systems due to soiling of the panels. Soiling is the natural occurrence of debris accumulation on panels, depending on local climate conditions. Soiling loss refers to efficiency lost due to dirt and dust accumulation on the panels. The debris reduces system output by shading on a smaller scale. In addition to uniform soiling, corner soiling is observed in framed modules as debris collects in the corners of the modules. While solutions currently exist to clean modules to mitigate soiling losses, these solutions are often expensive and time …

Early Wildfire Detection With Line Sensors, Virginia Yan

Master's Theses

Over the last few years, wildfires have become more devastating to communities as the fires are inevitably destructive to many homes, businesses, and ecosystems. Frequent wildfires also pose a significant threat to power grids and nearby residents as they can damage transmission lines and other electrical equipment, which in turn can cause major power shutdowns. Especially in western U.S., severe drought conditions and weather variability cause residents to become more vulnerable to wildfire disasters as their safety is threatened. We are incompetent to control the wildfires effectively despite existing advanced technologies. Hence, an algorithm based on energy conservation and heat …

Smart Solar Charge Controller, Aria Pegah, Miclaine Emtman

Electrical Engineering

The technology of photovoltaics has been quickly evolving as we move toward a future with more clean energy. Energy conversion efficiency is key to making these systems the viable option amongst other sources of power. This project proposes a way to increase the power yield from a solar system by implementing smarter algorithms in the maximum power point tracking (MPPT) component of the system. MPPT is critical because environmental conditions may vary significantly for any given system due to irradiance and shading. The proposed method for MPPT utilizes a controller that uses swarm intelligence to do the power tracking.. This …

Dc-Dc Buck-Boost Converter Design For Energy Harvesting From Exercise Equipment, Nicholas Serres

Electrical Engineering

This project aims to improve energy harvesting efficiency from an exercise machine. Exercise machine energy harvesting has a small immediate impact but can eventually have an immense impact. An elliptical exercise machine energy converter outputs 5V-60V whereas the microinverters require approximately 36V. The buck boost DC-DC converter bridges the gap between the microinverter and the elliptical machine. Increasing the buck-boost controller efficiency increases power production. Greater power efficiency gives the whole system more financial viability, and additionally makes it a greater sustainable energy source.

Field Testing The Effects Of Low Reynolds Number On The Power Performance Of The Cal Poly Wind Power Research Center Small Wind Turbine, John B. Cunningham

Master's Theses

This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, C­_p, vs. tip speed ratio, λ, characteristics. A description of both the wind turbine and test setup are provided. Data filtration and processing techniques were developed to ensure a valid method to analyze and characterize wind power measurements taken in a highly variable environment. The test results demonstrated a significant drop in the …

Iot Camera System For Monitoring Strawberry Fields, Simon Schoennauer

Master's Theses

A wireless imaging system for monitoring strawberry fields provides enough quality image data for computer vision algorithms to make meaningful yield predictions. This report contains a design for a wireless sensor network modified with mesh networking techniques to extend coverage range and a solar energy harvesting system to improve sensor node lifetime. A two hop system with six nodes is implemented in a laboratory environment validating the communication systems integrity over an 800’ range. Moving from a primary battery system to solar energy harvesting increases the module lifetime indefinitely.

Boost Converter Inductor Sizing Effects On The Performance Of Mppt Algorithms, Alan Nonaka

Master's Theses

With solar power and other renewables set to take over the market in the coming decades, maximum power point tracking will be essential to optimizing power output. One underserved topic of research is the effect of inductor current ripple on performance of Maximum Power Point Tracking (MPPT) algorithms. Many new topologies are focused on decreasing the ripple from PV source to increase efficiency and power output. However, not much has been done to show ripple degrading performance of MPPT algorithms. This study uses a boost converter topology to test the performance of constant duty cycle step Perturb and Observe (PO), …

Bi-Directional Dc-Dc Converter, John W. Hamlin, Oscar Ambriz, Luis Onofre

Electrical Engineering

This project was developed with the purpose of creating an efficient energy management system for the DC House project, with a centralized 12V battery system fed by a 48V Multiple Input Single Output Source (MISO). The energy management system will consist of a bidirectional DC-DC converter. During the day when the renewable sources produce enough energy to fulfill the load’s energy demand, the converter will make use of the excess energy by taking a 48V DC input and stepping it down to a 12V DC output in order to charge a 12V 100 Ah battery. When renewable sources can no …