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 results were obtained through simulations and verified by experimental results through a complete test configuration. Converter topology viability was confirmed through hardware testing and characterization.

ABSTRACT Designing Anti-Islanding Detection Using the Synchrophasor Vector Processor Ruth Huang The need for distributed generation (DG) has become more and more popular because of the adverse effects of fossil fuels and the fear of running out of fossil fuels. By having DG, there are less transmission losses, voltage support, controllability of the system, decreased costs in transmission and distribution, power quality improvement, energy efficiency, and reduced reserve margin. The adverse effects of DG are voltage flicker, harmonics, and islanding. Islanding occurs when the DG continues to energize the power system when the main utility is disconnected. Detecting islanding is important for personnel safety, speedy restoration, and equipment protection. This paper describes the different islanding methods currently used and the benefits of combining two passive islanding detection methods, under/over voltage detection and voltage phase jump detection methods, using the synchrophasor vector processor (SVP).

A microgrid is a local energy grid that could be disconnected from the larger grid and operate autonomously. This particular segment of the power industry is growing due to its reliability during times of emergency and crisis. Among these benefits are improved efficiency, lower operating costs, renewable generation sources, and improved resiliency of the regional electric grid. Communities can better prepare for unprecedented weather like wildfires, hurricanes, and other natural disasters. Regions that produce renewable energy can export their surplus through high voltage transmission lines to balance power supply and demand needs. This Underground High-Voltage Transmission Network project aims to design a blueprint for an underground high voltage transmission network that connects the Cal Poly Solar Farm to campus via an underground network. This Solar Farm produces 4.5MW and provides a quarter of Cal Poly’s power demand, making it essential to everyday operations on campus. The safety of the communities living around these areas is a top priority. The project develops methods to examine network resiliency and analyze load growth or demography trends. These methods include: using GIS to properly locate any existing underground infrastructure and utilizing CYMCAP software to size cable. We use ETAP software to run load flow analysis and device coordination simulation.

This report demonstrates improvements made in battery charging and battery management technology through the design of a universal programmable battery charger with optional battery management system attachment. This charger offers improvements in charge efficiency and unique battery charging algorithms to charge a variety of battery chemistries with variety of power requirements. Improvements in efficiency result from a synchronous Buck Controller topology as compared to previous universal chargers that use asynchronous Buck-Boost Converter topologies. This battery charger also surpasses current universal battery chargers by offering different charge modes for different battery chemistries. Charge modes provide the user an option between extending the life of the battery by selecting a mode with a slower, less stressful charge rate or a shorter charge time with a fast, more stressful charging mode. The user can also choose a charge mode in which the battery charges to full capacity, resulting in maximum runtime or a less than full capacity, which puts less stress on the battery thus extending the lifetime. Ultimately, this system permits weighing the performance tradeoff of battery lifetime and charge time. The optional battery management system attachment offers more precise monitoring of each cell and cell balancing for Li-Ion batteries. This further enhances the performance of the charger when integrated, but is not necessary for charger operation. The battery charger consists of three subcircuits: A microcontroller unit, a power stage, and a current sensing circuit. A C2000 Piccolo F28069 microcontroller controls a LM5117 Buck Controller by injecting a pulse-width modulated signal into the feedback node controlling the output of the buck to set a constant current or constant voltage thus creating a programmable battery charger. The pulse-width modulated signal changes according to charge algorithms created in software for specific battery chemistries and charge requirements. An analog-to-digital converter on the microcontroller monitors battery voltage by using a voltage divider and an INA169 current shunt monitor, which outputs a voltage corresponding to the charge current to another analog-to-digital converter on the microcontroller, monitors the charge current. This allows the charger program to maintain correct and safe charging conditions for each charge mode in addition to measuring output power. Lights on the microcontroller display a real-time status to the user of which portion of the charge profile the charger is in. A solid red light means the charger is in the constant current portion of the charge profile. A blinking red light means the charger is in the constant voltage portion. No red light means the battery charger finished and the battery is currently charged above nominal voltage. The battery charger works with the battery management system in the next section to provide ultimate battery charging and managing capabilities. The battery management system consists of two subcircuits: A microcontroller and a battery monitoring circuit. The MSP430FR5969 microcontroller unit communicates with BQ76PL536 battery management integrated circuits to create a battery management system that monitors data such as cell voltage, pack voltage, pack temperature, state of charge, fault statuses, alert statuses, and a variety of other useful cell parameters. This data displays on a liquid crystal display screen through different menu options. The user scrolls through the menus using a capacitive touch slider on the microcontroller unit and selects a given option using the option select button. A cell balance mode allows the user to check the balance of the cells and allows cell balancing if the cells differ by more than a set threshold.

Electric power system (EPS) is an integral part of infrastructure systems. Ensuring its resiliency to extreme weather events and natural hazards is crucial to protect the safety, economy and public health. Recorded and projected data show an increase in the frequency and severity of extreme weather events and natural hazards attributed to a changing climate. It is critical to ensure the integrity of the aging infrastructure systems and to promote environmental justice by shrinking the energy-equity gap to lower power outages in disadvantaged communities. An important aspect is the resiliency interdependency of EPS to other critical infrastructure systems, an aspect that has been escalating due to rapid urbanization and technological developments. The main objective of this research is to quantitatively evaluate the resilience of levee-protected power grid to flooding in a changing climate and adapting a strategy to enhance the resilience of power grid. Thus, this study first establishes a methodological and multi-disciplinary framework by integrating climate science, hydrology, and EPS analysis to study (I) how climate change affects recurrence intervals of flooding, (II) how the integrity of levees will be affected by changes in flooding patterns, (III) how these changes affect the resilience of an EPS located in levee-protected areas, and (IV) how to improve the resilience of the EPS while reducing the energy-equity gap. The proposed framework is applied to some IEEE standard test systems overlaid on a levee-protected area in Northern California. First, a link-based resiliency analysis is performed using the direct current optimal power flow (dc-OPF) method applied to the IEEE-24 standard test system. Then, a node-based resiliency analysis is carried out employing the IEEE 118-bus test system. The system resiliency is assessed for pre-flooding, historic flooding, and projected future flooding scenarios using two representative climate pathways (RCP). Finally, an optimal adaptation strategy using the placement of distributed energy resources (DERs) is delineated using a modified IEEE 30-bus test system to reduce flooding-induced power outages, prioritizing disadvantaged communities by minimizing energy inequity among the communities. Results of this study reveal that the adaptation plan can reduce the risk of power outages, improve environmental justice and the resilience of power networks. The findings of this study can contribute towards more resilient EPS under a changing climate.

The power system is a complex entity with unique plant designs, control systems, and market strategies. For many years, engineers have developed advanced technology to keep the grid efficient and balanced. With the rise of renewable sources, some new technology and programs must be developed to keep the quality of the power system. Unlike traditional power plants, renewable energy is highly dependent on environmental factors, such as sunlight and wind, meaning the generation depends on an unpredictable source of fuel. As the grid moves to more sustainable sources, the power market faces a growing challenge of less control over the forecasted supply offered by each renewable plant. This uncertainty creates a high need to develop alternative methods to ensure the power supply always meets demand. With diminishing control over our generation, one potential solution has been to explore demand response initiatives. Demand response focuses on the engagement of consumers to reduce the electricity demand, facilitating sub-hourly efforts on the supply side. This paper will analyze the effect of demand response efforts on the participants and provide insights into potential benefits and challenges associated with implementing demand response strategies. The findings of the studies will contribute to a better understanding on the compensation structure of current Direct Load Control programs and the level of participation required for it to be effectively integrated into the power system, promoting a more reliable and sustainable future.

Environmental experts agree that climate change is the biggest challenge facing our planet, and renewable energy and wind power are two important ways to curb it. Many governments promote these choices as environmentally friendly. There is a great deal of acceptance of wind power, with many people viewing it as an environmentally-friendly option that can help reduce emissions. Wind power has both positive and negative impacts on humans, with some findings indicating that the technology can have effects on human health. Some concerns include noise levels, visual impact from turbines, and potential effects of wind farms. Noise and shadows are the two most significant impacts in Sweden, while visual impact is more prevalent in India. Several improvements to the two countries' strategies have been made over the past few years. The proposed project has been created with the aim of promoting further development of wind power, which could have a significant impact on the environment and human health. Government incentives are being given to the deployment of renewable energy, such as wind power. This is in an effort to reduce carbon emissions and make a positive impact on the environment. In order to be used as sources in India, materials must be re-adopted and undergo standardized procedures. Public participation was promoted by the Swedish government in order to ensure that changes were made to the country's energy sources. This strategy was intended to foster a more open and participatory environment, which would ultimately lead Rephrase Energy should be included in the system, either as a producer or consumer.

Electrochemical conversion devices are a developing technology that prove to be a viable and more efficient alternative to current environmentally friendly generation devices. As such, constant research has been done in the last few decades to increase their applications and reliability. One of these systems, and the focus of this research, is the single cell Solid Oxide Fuel Cell (SOFC). These systems are a developing technology which main caveat is the need of high operating temperatures and costs. As such, most multidisciplinary research has been focused on researching materials and/or processes that help mitigate the costs or lower the operating temperature. The research presented in this paper focused on the manufacturing of a cubic stabilized zirconia (CSZ) electrolyte thin membrane for a single cell SOFC through tape casting. Thus, the process was divided into slurry preparation, tape casting, further processing, and analysis of samples. First the tape was produced reaching optimal viscosity (between 500 to 6000 cP) and minimizing impurities. Then, the slurry was poured into the doctor's blade with a 200 micrometers gap and allowed to dry. Samples were punched from the green tape with a diameter of 28 inches. Afterwards, these samples were pressed and sintered with a force of 218016 N and temperature of 1550 degrees celsius, respectively. These steps are done to maximize density and grain growth and minimize porosity. Lastly, the tape went further analysis and it was stated that further research should be done to determine this tape viability for stationary SOFC application.

<p>Measurements of thallium and indium doped Silicon-On-Insulator rib waveguidesshow optical absorption at a wavelength of 1550nm, dependent on the charge stateof the associated deep-level. Therefore, it is possible to use this effect to modulatewaveguide transmission by means of local depletion and/or injection of free-carriersto change deep-level occupancy. A one-dimensional model based on the generationand recombination process described by the modified Shockley-Read-Hall (SRH)mechanism was developed using MATLABc programming language in order to computethe optical absorption of a 1550nm wavelength as a function of the density ofneutrally-charged thallium or indium centers. This numerical model is in reasonableagreement with the experimental data for samples co-doped with low and mediumphosphorus concentrations. The values of optical absorption cross-section calculatedfor thallium are 2.9×10−17 ± 0.25cm2 and 3.2×10−17 ± 0.12cm2 for ion implantationdoses of 7.4×10−13cm−2 and 1.2×10−14cm−2, respectively. Also described is the thedesign, fabrication and characterization of an optical modulator using a four-terminalp+pnn+ diode on an indium-doped Silicon-On-Insulator rib waveguide. Modulationby controlling the charge state of deep impurity levels in silicon was thus demonstrated.Modulation bandwidth in the 2-10MHz regime was measured and the depthof modulation is approximately 0.48dB/V in forward bias and 0.25dB/V in reversebias. This is the first report of the implementation of an optical silicon-waveguidemodulator based on a periodically interleaved pn-junction configuration. In addition,the influence of indium, as a dopant in silicon (utilizing the Impurity PhotovoltaicEffect), as a means to increase the efficiency of a thin film silicon solar cell wasinvestigated using the same samples. Under certain doping conditions and geometricalconfigurations, a cell efficiency greater than 24% was measured —a somewhatremarkable result for these silicon thin films of 2.5μm</p> / Doctor of Philosophy (PhD)

<p>We examine energy harvesting sensor networks, more specifically, a sensor network using the Geographic Routing with Environmental Energy Supply (GREES) algorithm. We start with a discussion of other sources of energy conservation both in energy harvesting and non-energy harvesting sensor networks. Ideas presented in these works are combined where possible with the GREES algorithm. A sensor network was actually built to test and (if possible) improve the algorithm. There were problems along the way, but they were overcome to produce a functioning energy harvesting sensor network that used solar cells as the energy harvesting unit. Tests were run on the network by giving a consistent light and battery supply, and then changing parameters of the algorithm to see their effect on the lifetime of the network, indicating the network's sensitivity to individual parameters. These results are presented, along with their interpretation, as well as an error analysis detailing the behaviour of the algorithm. We discuss how sensitive the network is to each parameter, indicating which parameters are more important to calibrate or measure correctly.</p> / Master of Applied Science (MASc)