Power and Energy Commons^™

Modeling And Analysis Of A Photovoltaic System With A Distributed Energy Storage System, Anthony Winston Ma

Master's Theses

As California continues to integrate more renewable energy into its electrical system, the state has experienced a corresponding rise in photovoltaic system installations. PV arrays are a unique source of power generation in that they are affected by the location of the sun, shading, and temperature changes. These characteristics make solar one of the most highly variable forms of renewable energy. In order to improve solar power’s consistency, PV systems require a supplemental source of power. The primary focus of this paper is to determine if distributed energy storage systems can be used to reduce the effect of solar intermittency. …

Efficiency Performance Improvement Using Parallel Dc-Dc Converters With A Digital Controller, Daniel Forbes

Master's Theses

A system to improve efficiency performance of a DC-DC converter is simulated and built. The proposed system combines multiple DC-DC converters in parallel and implements a digital control scheme and load-share controller. A model of the system is developed in MATLAB Simulink and the model demonstrates the improved converter’s efficiency particularly at low load conditions. This simulation is then designed into a hardware system running three DC-DC converters in parallel, controlled by a microcontroller and a load-share controller. The hardware also confirms the simulation results, although some hardware refinements are evident as simulation results are superior. The system is designed …

Polar Field Oriented Control With 3rd Harmonic Injection, Martin Todd Hess

Master's Theses

Abstract

POLAR FIELD-ORIENTED CONTROL

with

3^RD HARMONIC INJECTION

Martin Todd Hess

Field Oriented Control (FOC), also known as vector control, is a widely used and well documented method for controlling Permanent-Magnet Synchronous Motors (PMSM) and induction motors. Almost invariably the orientation of the stator and rotor (field) fluxes are described in rectangular coordinates. In this thesis we explore the practicality of using polar coordinates.

Third harmonic injection is also a well-known technique that allows full utilization of the bus (DC-link), thus allowing the motor to run to full base speed without the use of field weakening. This technique potentially …

Digitally Controlled, Modular Electronic Load, Jason L. March

Master's Theses

This project entails the design and development of a digitally controlled, modular electronic load. The proposed load is unique from existing designs because it has the added ability to increase its maximum current level by adding identical modules in parallel. Each module is designed to sink a maximum of 5A at 60V but more modules allow for more current. The cost and simplicity of the design are considered such that it can be reproduced in-house to replace, whenever possible, the resistor box for load testing of any analog circuits but more specifically power electronic circuits.

The design process as well …

Modeling And Analysis Of A Four-Switch Buck-Boost Dynamic Capacitor, Oscar Plasencia

Master's Theses

Modern electric power utilities are facing a variety of challenges introduced by the increasing complexity of their operation, structure, and consumer loads. One such challenge has been to supply the ever growing demand for reactive power which is essential for grid support. For this reason dynamic VAR technologies are becoming much more important to modern day power systems. A recent dynamic VAR technology known as the Dynamic Capacitor offers full quadrant capacitive VAR control through the combination of AC/AC buck and boost cells. This paper introduces a new topology deemed the “Four-Switch Buck-Boost Dynamic Capacitor” which promises to combine the …

Impacts Of Plug-In Electric Vehicle On Residential Electric Distribution System Using Stochastic And Sensitivity Approach, Henry Chigozie Ureh

Master's Theses

Plug-in Electric Vehicles (PEVs) are projected to become a viable means of transportation due to advances in technology and advocates for green and eco-friendly energy solutions. These vehicles are powered partially, or in some cases, solely by the energy stored in their battery packs. The large sizes of these battery packs require large amount of energy to charge, and as the demand for PEV increases, the increase in energy demand needed to recharge these PEV batteries could pose problems to the present electric distribution system. This study examines the potential impacts of PEV on a residential electric distribution system at …

Development And Prototyping Of A Ground Fault Circuit Interrupter For 3-Phase 480 Volt Systems, Matthew R. Norlander

Master's Theses

Ground Fault Circuit Interrupter (GFCI) technology was first introduced in the NEC in 1971, yet four decades later the technology has not been introduced to a great extent outside of the home environment. This thesis introduces the difficulties encountered in low-voltage three phase ground fault current detection, and adopts a previously patented tripping scheme to develop and prototype a digital relay for 3-phase 480 volt systems capable of the sensitivity and speed required for personnel safety. Results demonstrate the feasibility of the concept and suggest commercial development should be pursued. The prototype is capable of mA sensitivity and reliably detects …

Evaluation Of Cathode Materials For Low Temperature (500-700c) Solid Oxide Fuel Cells, Alexander M. Lassman

Master's Theses

Solid oxide fuel cells (SOFC) have gained a great deal of interest, due to their potential for high efficiency power generation and ability to utilize hydrogen fuel, as well as various hydrocarbon-based fuels. A recent trend in SOFC development has been towards lower operating temperatures (500-700°C), which can substantially reduce the cost and complexity of the system. This thesis presents an investigation into state of the art Ba- and La- based cathode materials for use in low temperature (500-700°C) solid oxide fuel cells.

Synthesis of A-site deficient [A=0.97] Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃ (BSCF) was …

Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward

Master's Theses

This study focuses on both the numerical and experimental investigations of the novel, passively operated, tubular-shaped, Direct Methanol Fuel Cell (DMFC) as an alternative geometry to the traditional planar-shaped fuel cell. The benefit of the tubular geometry compared to the planar geometry is the higher instantaneous volumetric power density provided by the larger active area, which could be beneficial in applications that require a high instantaneous power while occupying a small volume. First, a two-dimensional, two-phase, non-isothermal model was developed to investigate the steady-state performance and design characteristics of a tubular-shaped, passive DMFC. It was found that a higher ambient …

Benefits Of Near-Term Cloud Location Forecasting For Large Solar Pv, Timothy Robert Rudd

Master's Theses

As the ‘green’ energy movement continues to gain momentum, photovoltaic generation is becoming an increasingly popular source for new power generation. The primary focus of this paper is to demonstrate the benefits of close-to real-time cloud sensing for Photovoltaic generation. In order to benefit from this close-to real-time data, a source of cloud cover information is necessary. This paper looks into the potential of point insolation sensors to determine overhead cloud coverage. A look into design considerations and economic challenges of implementing such a monitoring system is included. The benefits of cloud location sensing are examined using computer simulations to …

Bridgeless Active Power Factor Correction Using A Current Fed Push Pull Converter, Jeramie Seth Bianchi

Master's Theses

ABSTRACT

Bridgeless Active Power Factor Correction

Using a Current Fed Push Pull Converter

Jeramie Seth Bianchi

Switched Mode Power Supplies have become increasingly popular for efficient methods of delivering power to an assortment of electronic devices. This thesis proposes a method of using a current fed push pull converter to provide active power factor correction and rectification in a single stage. While most AC-DC converters utilize a bridge rectifier to convert AC-DC and then perform DC-DC conversion, the proposed circuit will utilize its output diodes to perform rectification, thus eliminating the need for a bridge rectifier. This circuit will also …

Plug-In Hybrid Electric Vehicle Impacts On A Central California Residential Distribution Circuit, Darren Janigian

Master's Theses

The adoption of plug-in hybrid electric vehicles (PHEV) as a means of transportation over conventionally fueled vehicles introduces new challenges to the existing infrastructure of the electrical transmission and distribution system.  PHEV battery charging can represent a significant power demand that has the potential to overload electrical distribution components.  This study examines the impacts of PHEV charging on household service transformers, distribution conductors and voltage levels of a Central California residential distribution system.  The system is simulated using ETAP power system analysis software.  Transformers are the most vulnerable to overloads, especially if PHEV charging occurs in clusters.  Main feeder conductors …

Off-Grid Public Lighting System – Design And Characterization Of An Led Luminaire, Quanghuy Le

Master's Theses

The technological advances made in the photovoltaic industry have led to a vast exploration of self-sustaining systems.  As the consumer demand for electricity rises from increasing population and development of existing technologies, new practices in system designs are required to relieve the impact on the electrical grid.

This thesis delves into a developing concept of using photovoltaic modules for roadway lighting, with emphasis on establishing the fundamental design for a “spot-lighting” luminaire.  By effectively extinguishing various sections of the luminaire in the absence of pedestrian trafficking, the proposed design and implementation will minimize the prolonged costs, as well as the …

Energy Harvesting From Exercise Machines: Forward Converters With A Central Inverter, Nicholas Keith Lovgren

Master's Theses

This thesis presents an active clamp forward converter for use in the Energy Harvesting From Exercise Machines project.  Ideally, this converter will find use as the centerpiece in a process that links elliptical trainers to the California grid.  This active clamp forward converter boasts a 14V-60V input voltage range and 150W power rating, which closely match the output voltage and power levels from the elliptical trainer.  The isolated topology outputs 51V, higher than previous, non-isolated attempts, which allows the elliptical trainers to interact with a central grid-tied inverter instead of many small ones.  The final converter operated at greater than …

Modeling And Analysis Of The Effects Of Pcb Parasitics On Integrated Dc-Dc Converters, Darwin Domingo Fernandez

Master's Theses

Load transients are prevalent in every electronic device including semiconductor memory, card readers, microprocessors, disc drives, piezoelectric devices, and digitally based systems. They are capable of producing voltage stress, introducing noise, and degrading device functionality. In order to avoid damage to the device, a feedback control loop is implemented with system compensation to regulate the output voltage deviations by the converter. Because designing compensation networks can be rather complicated, DC-DC converters with integrated feedback control topologies help minimize design time and complexity of converter compensation at the expense of design flexibility. This thesis widens the limitations of an integrated DC-DC …

Photovoltaic Emulator Adaptable To Irradiance, Temperature And Panel Specific I-V Curves, Joseph Gamos Durago

Master's Theses

This thesis analyzes the design and performance of a photovoltaic (PV) emulator. With increasing interest in renewable energies, large amounts of money and effort are being put into research and development for photovoltaic systems. The larger interest in PV systems has increased demand for appropriate equipment with which to test PV systems.

A photovoltaic emulator is a power supply with similar current and voltage characteristics as a PV panel. This work uses an existing power supply which is manipulated via Labview to emulate a photovoltaic panel. The emulator calculates a current-voltage (I-V) curve based on the user specified parameters of …

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. …

Design And Analysis Of A Wind Energy Harvesting Circuit Using Piezoelectric Polymers, Jameson J. Thornton

Master's Theses

This thesis investigates a relatively new method for harvesting wind energy by using flexible piezoelectric polymers with additional sails to increase their ability to harvest wind energy. This paper also introduces a new topology deemed the “stacked buck” that allows for multiple inputs to a system with a single output. Derivations and analysis detail the workings of the “stacked buck” with a laboratory test to show a working model. This paper also reports another experiment done in a wind tunnel to analyze the capability of the piezoelectric polymers as sources to the “stacked buck” topology with measurements of the power …

A Study Into The Use Of Microprocessor Relays For Motor Operated Valve (Mov) Electrical Protection In Nuclear Power Plants, James Andrew Tuccillo

Master's Theses

Motor Operated Valves (MOVs) are electro-mechanical components used to isolate, divert, or introduce fluid flow. The use of microprocessor relays for actuator motor electrical protection within nuclear power plants is the focus of this thesis and is implemented by providing a new and enhanced protection scheme that provides the adequate conservatism necessary to ensure valve operation while still maintaining electrical safety and continued operational availability. The comprehensive protection scheme is designed around an advanced microprocessor relay that has the ability to simulate the thermal overload conditions of a motor operating into a destructive thermal region. Through laboratory testing, the validity …

Effects Of Cloud-Induced Photovoltaic Power Transients On Power System Protection, Joel A. Nelson

Master's Theses

As the world strives towards finding alternative sources of power generation, photovoltaic generation has become an increasingly prevalent alternative energy source on power systems world-wide. This paper studies the effects that incorporating photovoltaic generation has on the existing power systems and their power system protection schemes. Along with the addition of this emerging alternative energy source comes the volatility of PV power generation as cloud-cover produces erratic variations in solar irradiance and PV power production. Such variations in PV power may lead to unfavorable operating conditions and power system failures. The issues addressed in this paper include a study of …

Enhanced Cal Poly Super System Simulink Model, Matthew Ogden Mcfarland

Master's Theses

The Cal Poly Sustainable Power for Electrical Resources (SuPER) project is a solar power DC distribution system designed to autonomously manage and supply the energy needs of a single family off-the-grid home. The following thesis describes the improvement and re-design of a MATLAB Simulink model for the Cal Poly SuPER system. This model includes a photovoltaic (PV) array, a lead-acid gel battery with temperature effects, a wind turbine model, a re-designed DC-DC converter, a DC microgrid, and multiple loads. This thesis will also include several control algorithms such as a temperature controlled thermoelectric (T.E.) cooler, intelligent load switching, and an …

Asynchronous Mips Processors: Educational Simulations, Robert L. Webb

Master's Theses

The system clock has been omnipresent in most mainstream chip designs. While simplifying many design problems the clock has caused the problems of clock skew, high power consumption, electromagnetic interference, and worst-case performance. In recent years, as the timing constraints of synchronous designs have been squeezed ever tighter, the efficiencies of asynchronous designs have become more attractive. By removing the clock, these issues can be mitigated. How- ever, asynchronous designs are generally more complex and difficult to debug. In this paper I discuss the advantages of asynchronous processors and the specifics of some asynchronous designs, outline the roadblocks to asynchronous …

Distributed Generation: Issues Concerning A Changing Power Grid Paradigm, Scott G.M. Therien

Master's Theses

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …

Near Real-Time Exercise Machine Power Statistics Reporting, Brendan C. Asche

Master's Theses

Cal Poly’s Recreation Center expansion project provides an opportunity to implement Energy Harvesting From Exercise Machines (EHFEM). Part of this implementation is a system that reports the exercise machines’ energy production. Although products capable of reporting exercise machine energy harvesting statistics exist, they have limited capabilities. This thesis project defends a system capable of reporting exercise machine power statistics in near real-time.

The system consists of display, database, and power measurement modules. The display module presents statistics in an interactive, graphical, and widely-accessible way. The database module provides an efficient way of organizing and accessing stored statistics. Multiple power measurement …

High Voltage Resonant Self-Tracking Current-Fed Converter, Scott Logan Mcclusky

Master's Theses

High voltage power supply design presents unique requirements, combining safety, controllability, high performance, and high efficiencies. A new Resonant Self-Tracking Current-Fed Converter (RST-CFC) is investigated as a proof-of-concept of a high voltage power supply particularly for an X-ray system. These systems require fast voltage rise times and low ripple to yield a clear image.

The proposed converter implements high-frequency resonance among discrete components and transformer parasitics to achieve high voltage gain, and the self-tracking nature ensures operation at maximum gain while power switches achieve zero-voltage switching across the full load range. This converter exhibits an inherent indefinite short-circuit capability. Theoretical …

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey

Master's Theses

ABSTRACT

Multidisciplinary Design Optimization of an Extreme Aspect Ratio HALE UAV

Bryan J. Morrisey

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. Presently, several development efforts are underway in this field, including a project sponsored by DARPA that aims at producing an aircraft that can sustain flight for multiple years and …

Novel Current-Fed Boundary-Mode Parallel-Resonant Push-Pull Converter, Jonathan David Paolucci

Master's Theses

The inherent difficulty in designing high voltage power supplies is often compounded by demands of high reliability, high performance, and safe functionality. A proposed high step-up ratio DC-DC converter meets the exacting requirements of applications such as uninterruptible power systems, radar, and pulsed power systems. The proposed DC-DC converter topology combines a multi-phase buck input stage with a novel self-tracking zero-voltage-switching (ZVS) resonant output stage. Traditionally, the inclusion of multiple power processing stages within a power supply topology severely degrades the overall converter efficiency. Due to the inherent high efficiency per stage, however, this effect is minimized. The self-tracking switching …