Engineering Commons^™

Smart Dc Wall Outlet Design With Improved Load Voltage Detection, Patrick Donovon Granieri

Master's Theses

A standard home in the United States has access to the 120V AC power grid for use with home appliances. Many electronics used at home are powered by a DC power supply, which loses energy in the conversion from AC power. The DC House project avoids any conversion between AC and DC by storing energy in batteries as DC power and supplying it directly to DC appliances. While AC systems feature a standardized output voltage, no such standard exists for DC systems. The Smart DC Wall Outlet solves this by automatically adjusting its output voltage to meet any required DC …

Dc To Dc Usb-C Charger, Nikki Gmerek, Kenneth Nguyen, Uriel Serna

Electrical Engineering

The DC House USB-C Charger will convert the 48V input from the DC house, found on the Cal Poly campus, to 3 USB-C outputs: 5V, 12V, and 24 volts. The converter will deliver a total of 185 Watts out across all 3 outputs, with an efficiency greater than 82% at full load. The USB-C ports will be used to connect to compatible phones, laptops or any other device for charging/powering purposes. The goal of this project is to develop the most efficient and safe converter to deliver power to multiple outputs using USB-C, for items as small as a cell …

Cal Poly Ee 518 Electric Power Protection Laboratory, Richard Terre, Vincent Tham, Austin Kurth

Electrical Engineering

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 utilizes microprocessor-based relays to reinforce the fundamental concepts of power system protection.

The electric power protection laboratory (EPPL) senior project is the validation of lab manuals written for the planned EE-518 power system protections laboratory looking to be offered in Spring 2020 alongside the current lecture class under the same designation. This report evaluates the lab manual, verifies …

Dc House Smart Pathway Lighting System, Benjamin H. Tan, Rafael Santiago, Brendan Schoemehl

Electrical Engineering

The Student Experimental Farm (SEF) is a two-acre site where students are able to create projects and experiments. It is also the location of the DC House project, a house with electricity provided by DC power as opposed to the traditional AC power. The motive of the DC house project is to provide affordable and renewable electricity for people living in remote areas where ac power grids are not available. Currently, the SEF does not have any lighting, so students would have to work in the dark after the sun sets. By creating a smart lighting system for the pathway …

Dc-Dc Converter For Electric Vehicle, Jason Y. Zhou, Nicholas James Mah

Electrical Engineering

In this work, a DC-DC converter is designed for an electric vehicle. The DC-DC converter is designed to provide 500W with a 200-400V input and a 12-15V adjustable output. Electric vehicle sales are beginning to increase in popularity and the need for DC-DC converters to siphon power from the tractive system is not yet fully satisfied, especially for single-seater class vehicles. Additionally, improving performance in efficiency without sacrificing wide input voltage range can benefit future DC-DC converter designs. In the end, a forward active clamp DC-DC converter is designed and tested. Additionally, spreadsheet calculators, LTSpice simulations, and Matlab scripts were …

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 …

Spread Spectrum Buck Converter, Summer Elise Rutherford, Kyle Brandon Halloran, Brian Taylor Arbiv

Electrical Engineering

Electromagnetic interference (EMI) is an issue prevalent to DC-DC converters. When a system doesn’t effectively filter out external noise or signals, these signals can cause disturbances to the system at large. The switching technology of DC-DC converters (PWM in particular), lends the system susceptible to EMI because there is a prevalent peaks at the switching frequency, meaning any external signals will not be effectively attenuated at this frequency. This can cause significant issues at the input bus of the DC-DC converters because this bus is likely the input of a multitude of devices; the EMI susceptibility caused by switching technology …

Apollo Photovoltaic Overview And Assessment, Andrew S. Hollis, James P. Tran, Andes Le, Regita Soetandar

Electrical Engineering

This senior project aims to take the various data sheets provided to us by PIVVIR Solar, the organization in charge of Apollo photovoltaic power plant, and perform an overall assessment as well as condensing the information into a more digestible and concise document. Currently, the documents provided to us by PIVVIR Solar are scattered and disorganized. Our goal is to take what we understand about photovoltaic power plants and combine it with the Apollo plant’s datasheets and summarize everything into one focused document that more readers can understand.

Pv Hybrid Inverter And Bess, Jacob Sussex, William Dresser, Owen Mckenzie, Jonathan Wharton, Derek Seaman

Electrical Engineering

The storage of energy from renewable sources such as photovoltaic based systems is a growing market, with 36 MWh of storage installed in Q1 of 2018. A report from EnergySage earlier this year states that in 2017, 74% of residential solar owners were also interested in energy storage systems. Mainstream systems like Tesla’s Powerwall are competing with other lithium-ion based storage systems from a wide number of providers on the market today. Short term and long term data collection on a system like this could be useful in designing future systems which perform better than the current market offerings. This …

Multiple Input, Single Output Dc-Dc Conversion Stage For Dc House, Jason Baltierrez

Master's Theses

n this thesis project, a proposed architecture for the multiple input, single output conversion stage for the DC House was designed, simulated, and tested. This architecture allows for multiple different input sources to be used to create a single higher power output source. The design uses a DC-DC boost converter with a parallelable output which has been demonstrated to allow increased total output power as a function of the number of input sources available. The parallelable output has been shown to distribute load amongst the input sources relatively closely to optimize the system. This approach is also desirable since it …

Directional Comparison Bus Protection Using Superimposed Partial Operating Current Characteristics, Bishwas Baral

University of New Orleans Theses and Dissertations

Various directional comparison bus protection methods including widely used superimposed directional element method need to have both voltages and currents from all feeders connected to the zone of protection to find the direction of current for detecting a bus fault or a line fault. The purpose of the thesis is to present a new technique for directional comparison bus protection to discriminate a bus fault from line fault and normal condition. The new technique, which is implementing superimposed directional element method to modify partial operating current characteristics (POC) method to superimposed POC (SPOC) method, does not use voltages from feeders, …

Operation And Planning Of Data Centers In Electricity Networks, Ali Vafamehr

Electrical Engineering Theses and Dissertations

Cloud computing provides unique opportunities for the various sectors of the economy such as the automotive industry, education, finance, and governmental entities. In-house IT infrastructures vary in quality and can often be outdated and ineffective. As an alternative, cloud computing is a popular IT model which allows various businesses to “outsource” the IT infrastructure to a more efficient model. Businesses are opting to use cloud computing in order to eliminate the capital expenses of traditional IT systems and reduce the around-the-clock expert manpower required to operate on-site IT infrastructures. Relying on cloud services gives businesses the flexibility to access a …

Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han

Chemical and Biological Engineering ETDs

In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal …

Optimal And Efficient Decision-Making For Power System Expansion Planning, Mahdi Mehrtash

LSU Doctoral Dissertations

A typical power system consists of three major sectors: generation, transmission, and distribution. Due to ever increasing electricity consumption and aging of the existing components, generation, transmission, and distribution systems and equipment must be analyzed frequently and if needed be replaced and/or expanded timely. By definition, the process of power system expansion planning aims to decide on new as well as upgrading existing system components in order to adequately satisfy the load for a foreseen future.

In this dissertation, multiple economically optimal and computationally efficient methods are proposed for expanding power generation, transmission, and distribution systems. First, a computationally efficient …

Exploring The Electrical Properties Of Twisted Bilayer Graphene, William Shannon

Senior Theses

Two-dimensional materials exhibit properties unlike anything else seen in conventional substances. Electrons in these materials are confined to move only in the plane. In order to explore the effects of these materials, we have built apparatus and refined procedures with which to create two-dimensional structures. Two-dimensional devices have been made using exfoliated graphene and placed on gold contacts. Their topography has been observed using Atomic Force Microscopy (AFM) confirming samples with monolayer, bilayer, and twisted bilayer structure. Relative work functions of each have been measured using Kelvin Probe Force Microscopy (KPFM) showing that twisted bilayer graphene has a surface potential …

Manufacturing And Testing The Permanent Magnet Linear Motor, Renjie Kang

Senior Theses

Controlled mechanical motion is vital in many useful applications in technology. Among them, linear motors have advantages over traditional rotating motors. In this work, we built a permanent magnet linear motor to test and measure its energy efficiency. A maximum 29% total energy efficiency, and 67% energy transfer rate, were detected. In addition, a C-shape support structure was added to the moving part in order to increase the moving accuracy. The tests show that, with the support structure, the fluctuation in the vertical direction decreases significantly, but the friction of the system slightly increases.

Modeling Solder Ball Array Interconnects For Power Module Optimization, Paul Swearingen

Electrical Engineering Undergraduate Honors Theses

PowerSynth is a software platform that can co-optimize power modules utilizing a 2D topology and wire bond interconnects. The novel 3D architectures being proposed at the University of Arkansas utilize solder ball interconnects instead of wire bonds. Therefore, they currently cannot be optimized using PowerSynth. This paper examines methods to accurately model the parasitic inductance of solder balls and ball grid arrays so they may be implemented into software for optimization. Proposed mathematical models are validated against ANSYS Electromagnetics Suite simulations. A comparison of the simulated data shows that mathematical models are well suited for implementation into optimization software platforms. …

Very Low Power Cockcroft-Walton Voltage Multiplier For Rf Energy Harvesting Applications, Trace Langdon

Electrical Engineering Undergraduate Honors Theses

A device was required that could harvest the electromagnetic energy present in ambient radio frequency (RF) signals. A part of this device must convert the AC RF signal received by the antenna into a DC signal that can be used in an embedded application. Since the RF signal amplitude is small, it must first be amplified and rectified to become a usable signal. The Cockcroft-Walton voltage multiplier is a subsystem of the design which ideally converts a 100 mV AC signal coming from the antenna to a 350 mV DC signal. The output of the voltage multiplier is used to …

Designing A Solar Pv System To Power A Single-Phase Distribution System, Ana Guerra Vega

Electrical Engineering Undergraduate Honors Theses

Over the last decade, the costs of PV system components have dropped more than 70%. Additionally, green energy incentives like the 30% tax credit have been pushed forward. PV solar systems have become accessible to the general public. Companies are pledging to reduce their carbon emissions.

As part of their green initiative, the City of Fayetteville has requested a feasibility study for a PV system to be installed on the rooftop of the Facilities Management building, 115 S. Church Ave, Fayetteville, AR, 72701. This thesis shows the design process of this PV system and the return on investment estimation. While …

Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak

Graduate Theses and Dissertations

With the introduction of sophisticated electronic gadgets which cannot sustain interruption in the provision of electricity, the need to supply uninterrupted and reliable power supply, to the consumers, has become a crucial factor in the present-day world. Therefore, it is customary to correctly identify fault locations in an electrical power network, in order to rectify faults and restore power supply in the minimum possible time. Many automated fault location detection algorithms have been proposed, however, prior art requires topological and physical information of the electrical power network. This thesis presents a new method of detecting fault locations, in transmission as …

H2 Control For Improved Stability Of Multi-Area Electric Power System With High Levels Of Inverter-Based Generation, Muthanna Abdulkareem Al-Sarray

Graduate Theses and Dissertations

Increased generation capacity from non-dispatchable energy resources such as wind and solar has created challenges to ensuring the reliable delivery of electric power. This research develops a systematic three-step method of assessing the reliability of electric power systems under a variety of different possible fault conditions to ensure that overall system stability is preserved in a manner the meets regulatory requirements. The first step is a risk-based reliability method (RBRM) that accounts for the probability of a line outage versus the severity of impact. This allows system planners to judiciously allocate expenses for reliability improvements based on the greatest economic …

Usb-C Power Adapter For Dc House Project, Tyler G. Starr, Ezzeddeen Gazali

Electrical Engineering

Despite the importance of electricity and the impact it has on our daily lives, many people around the world still live without this essential utility today. According to the International Energy Agency (IEA), approximately 1.1 billion people in the world did not have access to electricity in 2017. The DC House Project at Cal Poly aims to provide electricity to people living in rural areas by directly utilizing DC energy generated from renewable or human powered sources without the need for DC-AC conversions. However, one significant issue is the lack of a standardized DC wall socket. Standards for AC wall …

Public Utilities' Disaster Response And Management Plans: An Evaluation Of National Grid And New York State Electric & Gas, Taylor N. Vishion

Public Administration Master’s Projects

Societal dependence on electricity has rapidly increased as technological advancement has occurred, thus requiring electric utilities to advance their emergency response and repair procedures. Disaster management and response is a relatively new field for electric utilities, and despite the adoption of the Incident Command System created by FEMA, there are still opportunities for all utilities to improve. This project aims to assess the disaster response and management procedures of National Grid U.S. and NYSEG and identify opportunities for improvement. This study interviewed emergency management professionals experienced with electric utilities and found both National Grid U.S. and NYSEG can improve in …

A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, Aminta Naidili Castillo Robles

Graduate Theses and Dissertations

This thesis presents the design, simulation and test results of a silicon germanium (SiGe) complementary metal-oxide-semiconductor (CMOS) linear regulator. The objective of the circuit is to power other analog devices regardless of the load current and input voltage changes. The application of this regulator is to be part of a project developing a miniaturized semiconductor platform that can be inserted into stems of crops in order to measure data inside the plant and then send it wirelessly to the user. The linear regulator was designed on a BiCMOS SiGe 0.13µm which is a GlobalFoundries process. It has been tested at …

Local And Central Controllers For Microgrids, Edgar Ariel Escala Calame

Graduate Theses and Dissertations

The main objective of this thesis is to serve as a guide, so readers are able to learn about microgrids and to design simple controllers for different AC microgrid applications. In addition, this thesis has the objective to provide examples of simulation cases for the hierarchical structure of a basic AC microgrid which can be used as a foundation to build upon, and achieve more complex microgrid structures as well as more sophisticated power-converter control techniques.

To achieve these objectives, the modeling of voltage source converters and control design in the z-domain are presented. Moreover, the implementation and transient analysis …

Real-Time Fault Detection And Reconfiguration Of A Three-Phase Electric Motor Drive, Danyal Mohammadi

Boise State University Theses and Dissertations

Variable-frequency drives (VFDs) are widely used for control of electrical machines such as induction motors (IMs) or permanent-magnet synchronous motors (PMSMs). Similar to other electrical devices, these drives are subject to failure. Several types of faults are associated with VFDs. For instance, faults such as an open-switch fault, a short-circuit switch fault are the two common faults in VFDs. These faults can yield catastrophic consequences if proper remedial action is not taken.

A unique remedial topology for the post-fault period and a new pulse width modulation (PWM) strategy are proposed so that not only the motor drive can continue the …

Model Development And Assessment Of The Gate Network In A High-Performance Sic Power Module, William Austin Curbow

Graduate Theses and Dissertations

The main objective of this effort is to determine points of weakness in the gate network of a high-performance SiC power module and to offer remedies to these issues to increase the overall performance, robustness, and reliability of the technology. In order to accomplish this goal, a highly accurate model of the gate network is developed through three methods of parameter extraction: calculation, simulation, and measurement. A SPICE model of the gate network is developed to analyze four electrical issues in a high-speed, SiC-based power module including the necessary internal gate resistance for damping under-voltage and over-voltage transients, the disparity …

An Optimization Approach Based On The Interior-Point Methodology For The Tertiary Control Of Modernized Microgrids, Isaiah D. Woodruff

Honors College Theses

With the rise in popularity of the modernized microgrids (MMGs), the addition of a controller to maximize economic efficiency while considering environmental impact is crucial. Tertiary control is at the highest control level, considering economic concerns related to the optimal operation of the microgrid and using a sampling time from minutes to hours; tertiary controls manage the flow of power between the microgrid and the connected grid. In MMGs' tertiary controls, the use of optimization algorithms to minimize an objective function with equality and inequality constraints allows for powerful control over the system. In this paper, the interior-point algorithm is …

Effect Of Grain Size And Interface Engineering On The Photovoltaic Performance And Stability Of Perovskite Solar Cells, Abdullah Al Mamun

Electrical & Computer Engineering Theses & Dissertations

Organic-inorganic halide perovskite solar cells (PSCs) have grown rapidly in recent years due to their outstanding optoelectronic properties, high efficiency, and low-cost. However, this emerging solar cell technology is experiencing some challenges such as defects, hysteresis, and long-term stability, which need to be addressed in order to make it commercially available. This dissertation aims to assist in overcoming some of the barriers and is therefore important to the field of perovskite solar cells.

Initially, this dissertation focuses on investigating the role of grain interiors (GIs) and grain boundaries (GBs) of perovskite film using chemically, spatially, and temporally resolved measurements at …

Plasma Treatment Method For Ohmic Contacts On Zinc Oxide Thin Film Transistors, Blaine Z. Underwood

Theses and Dissertations

This research utilizes plasma treatments as a method to decrease the contact resistance on zinc oxide (ZnO) thin film transistors (TFT). In recent years, researchers have achieved gigahertz RF switch cutoff frequency with ZnO TFTs. To further increase the cutoff frequency, the total resistance of this device must be minimized. Modern ZnO TFTs are fabricated with submicron channel lengths, which contains minimal resistance due to the TFT channel, making contact resistance significant to the total resistance of the device. This research developed a method to integrate plasma treatments into the fabrication of ZnO TFT to decrease the contact resistance, thus …