<div> <div> <div> <p>Puerto Rico’s lack of effective and affordable energy substitutes after Hurricane Maria resulted in a mortality increase of 4,970 residents (Verma, Murray, and Mamdani, 2018). Puerto Rico’s Island dependency on electric power and no energy substitutes available have provoked a risk to human life after catastrophic events. The problem was measured by comparing Puerto Rico’s reliance on fossil fuels with accessible and economical renewable energy options. Solar photovoltaic (PV) technologies are the optimum alternative to transition from fossil fuel usage to renewable energy. Previous research has demonstrated the impact of using solar panels instead of an electric grid due to the constant solar radiation throughout the year. The analyzed data and projections showed a reduction in fossil fuels and carbon dioxide emissions by implementing solar photovoltaic technologies. The installation of PV systems in landfills, household roofs and transitioning to solar public lighting positively impacts the atmosphere carbon dioxide emissions. </p> </div> </div> </div>

In this work, power supply noise contribution, at a particular node on the power grid, from clock/power gated blocks is maximized at particular time and the synthetic gating patterns of the blocks that result in the maximum noise is obtained for the interval 0 to target time. We utilize wavelet based analysis as wavelets are a natural way of characterizing the time-frequency behavior of the power grid. The gating patterns for the blocks and the maximum supply noise at the Point of Interest at the specified target time obtained via a Linear Programming (LP) formulation (clock gating) and Genetic Algorithm based problem formulation (Power Gating).

Computing researchers have long focused on improving energy-efficiency?the amount of computation per joule? under the implicit assumption that all energy is created equal. Energy however is not created equal: its cost and carbon footprint fluctuates over time due to a variety of factors. These fluctuations are expected to in- tensify as renewable penetration increases. Thus in my work I introduce energy-agility a design concept for a platform?s ability to rapidly and efficiently adapt to such power fluctuations. I then introduce a representative application to assess energy-agility for the type of long-running, parallel, data-intensive tasks that are both common in data centers and most amenable to delays from variations in available power. Multiple variants of the application are implemented to illustrate the fundamental tradeoffs in designing energy-agile parallel applications. I find that with inactive power state transition latencies of up to 15 seconds, a design that regularly ”blinks” servers out- performs one that minimizes transitions by only changing power states when power varies. While the latter approach has much lower transition overhead, it requires additional I/O, since servers are not always concurrently active. Unfortunately, I find that most server-class platforms today are not energy-agile: they have transition la- tencies beyond one minute, forcing them to minimize transition and incur additional I/O.

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 and removes the faulted feeder from the system, without causing false tripping on non-faulted feeders. The prototype system has been tested and responds appropriately for faults over the 1 mA to 1000 A range.

This paper presents the design and development of a novel Arc Welding Power Supply utilizing a modified two-switch forward converter topology. The proposed design improves the power quality by improving power factor to near unity and reducing total harmonic distortion. State space analysis of the proposed circuit showed that the circuit followed a boost-buck input output relationship. Simulation of the circuit was first implemented in LTspice to verify the functionality of the new topology. Hardware implementation of the proposed design was built on a scaled-down prototype for a proof-of-concept of the new topology. The prototype specifications were created for a 5A, 20V output with a 20-24V, 60Hz input. This project demonstrated that the proposed new topology was successful in obtaining a near unity power factor and a total harmonic distortion of less than 2%. Additionally, the prototype followed the simulation and calculations of a boost-buck function while varying duty cycle, and the final measurements aligned well with waveforms from the simulation.

<p>Jedan od najvažnijih parametara kvaliteta električne energije u<br />distributivnoj mreži je harmonijski sastav naponskih i strujnih<br />signala. U disertaciji je razmatrano integrisano merilo harmonika,<br />na principu stohastičke rezonance. Uopštenje postojećeg teorijskog<br />modela rada merila, ostvareno je ukidanjem pojedinih pretpostavki o<br />idealizovanim uslovima rada: idealni intervali merenja, poznata i<br />nepromenljiva osnovna učestanost, idelane diterske sekvence. Na<br />osnovu teorijske analize, simulacija i praktičnih merenja, date su<br />procene reda veličine za svaku od navedenih grešaka. Na kraju je dato<br />šest preporuka za modifikaciju hardvera i načine obrade rezultata<br />merenja, koje mogu značajno poboljšati metrološke performanse<br />budućih generacija ovih merila.</p> / <p>One of the most important power quality indicators in power grids is the<br />harmonic composition of voltage and current signals. In this thesis an<br />integrated harmonic instrument has been considered, which operates on the<br />principle of the stochastic resonance. Generalization of the existing<br />theoretical model of the instrument was realized by terminating several<br />idealistic assumptions: perfect measurement intervals, known and stable<br />fundamental frequency, ideal dithering sequences. Based on the performed<br />theoretical analysis, simulations and practical measurements, estimates have<br />been given for each of the measurement error sources. Finally, six<br />recommendations were given for the modification of the hardware and the<br />results processing in order to achieve significantly better metrological<br />performances in future generations of this instrument.</p>

Electricity service providers (ESP) worldwide have increased their interest in the use of electrical distribution, transmission, generation, storage, and responsive load resources as integrated systems. Referred to commonly as "smart grid," their interest is driven by widespread goals to improve the operations, management and control of large-scale power systems. In this thesis I provide research into a novel agent-based simulation (ABS) approach for exploring smart grid system (SGS) dispatch, schedule forecasting and resource coordination. I model an electrical grid and its assets as an adaptive ABS, assigning an agent construct to every SGS resource including demand response, energy storage, and distributed generation assets. Importantly, real time is represented as an environment variable within the simulation, such that each resource is characterized temporally by multiple agents that reside in different times. The simulation contains at least as many agents per resource as there are time intervals being investigated. These agents may communicate with each other during the simulation, but only agents assigned to represent the same unique resource may exchange information between time periods. Thus, confined within each time interval, each resource agent may also interact with other resource agents. As with any agent-based model, the agents may also interact with the environment, in this case, containing forecasted environment, load and price information specific to each time interval. The resulting model is a time-independent global approach capable of: (1) capturing time-variant local grid conditions and distribution grid load balancing constraints; (2) capturing time-variant resource availability and price constraints, and finally, (3) simulating efficient unit-commitment real-time dispatches and schedule forecasts considering time-variant forecasted transactive market prices. This thesis details the need for such a system, discusses the form of the ABS, and analyzes the predictive behavior of the model through a critical lens by applying the resulting proof-of-concept simulation to a set of comprehensive validation scenarios. The resulting analysis demonstrates ABS as an effective tool for real-time dispatch and SGS schedule forecasting as applied to research, short-term economic operations planning and transactive systems alike. The model is shown to converge on economic opportunities regardless of the price or load-forecast shape and to correctly perform least-cost dispatch and schedule forecasting functionality.

This thesis presents a method for reliability assessment of a power grid with distributed generation providing support to the system. The distributed generation units considered for this assessment are Combined Heat and Power (CHP) units operated by individual customers at their site. CHP refers to the simultaneous generation of useful electric and thermal energy. CHP systems have received more attention recently due to their high overall efficiency combined with decrease in costs and increase in reliability. A composite system adequacy assessment, which includes the two main components of the power grid viz., Generation and Distribution, is done using Monte Carlo simulation. The State Duration Sampling approach is used to obtain the operating history of the generation and the distribution system components from which the reliability indices are calculated. The basic data and the topology used in the analysis are based on the Institution of Electrical and Electronics Engineers - Reliability Test System (IEEE-RTS) and distribution system for bus 2 of the IEEE-Reliability Busbar Test System (IEEE-RBTS). The reliability index Loss of Energy Expectation (LOEE) is used to assess the overall system reliability and the index Average Energy Not Supplied (AENS) is used to assess the individual customer reliability. CHP reliability information was obtained from actual data for systems operating in New England and New York. The significance of the results obtained is discussed.

Wide bandgap (WBG) devices and power electronic converters (PEC) that enable the dynamic control of energy and high-power density designs inevitably contain defects including sharp edges, triple points, and cavities, which result in local electric field enhancements. The intensified local electric stresses cause either immediate dielectric breakdown or partial discharge (PD) that erodes electrical insulators and accelerates device aging. With the goal of addressing these dielectric challenges emerging in power-dense applications, this dissertation focuses on 1) modeling the dielectric characteristics of supercritical fluids (SCFs), which is a new dielectric medium with high dielectric strength and high cooling capability; and 2) establishing the optimal fabrication conditions of electrets, which is a new dielectric solution that neutralizes locally enhanced electric fields. In this dissertation, the dielectric breakdown characteristics of SCFs are modeled as a function of pressure based on the electron scattering cross section data of clusters that vary in size as a function of temperature and pressure around the critical point. The modeled breakdown electric field is compared with the experimental breakdown measurements of supercritical fluids, which show close agreement. In addition, electrets are fabricated based on the triode-corona charging method and their PD mitigation performance is evaluated through a series of PD experiments. Electrets are fabricated under various charging conditions, including charging voltage, duration, polarity, and temperature with the goal of identifying the optimal condition that leads to effective PD mitigation. The PD mitigation performance of electrets fabricated based on these charging conditions is further assessed by investigating the impact of various power electronics voltage characteristics, including dv/dt, polarity, switching frequency, and duty cycle. Electret based electric field neutralization approach is further utilized in increasing the critical flashover voltage associated with the surface flashover voltage. Moreover, due to the high mechanical strength of epoxy composites at cryogenic temperatures, in this dissertation, epoxy-based electrets are fabricated as a solution to PD in high temperature superconducting cables. The experimental demonstrations conducted with electret in this dissertation is dedicated for the establishing the electret based electric field neutralization approach as a dielectric solution for the dielectric challenges in power electronics driven systems.

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 intelligent power source selector. Furthermore, a seven day simulation and evaluation of the results are presented. This simulation is an important tool for further system development, re-design, and long term system performance prediction.