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Condition-Dependent Risk Assessment Of Large-Scale Grid-Tied Photovoltaic Power Systems, Sherwin Li

Master's Theses

This thesis reviews the methods for evaluating the reliability of large PV systems and techniques for quantifying the impacts of PV interconnection on distribution system reliability. In addition, a comparative study is performed to evaluate the seasonal condition-dependent risk performance of central-inverter and string-inverter grid-tied PV power systems. Major contributions include: 1) risk analysis of seasonal impacts for string and centralized PV systems. Seasonal sensitivities of PV system risks to system structures, temperature variation, solar insolation, and capacitor equivalent series resistance are analyzed; and 2) the incorporation of the effect of operational conditions and the aging failure model into the …

Reliability Techniques For Data Communication And Storage In Fpga-Based Circuits, Yubo Li

Theses and Dissertations

This dissertation studies the effects of radiation-induced single-event upsets (SEUs) on field-programmable gate array(FPGA)-based circuits. It analyzes and quantifies a special case in data communication, that is, the synchronization issue of signals when they are sent across clock domains in triple modular redundancy (TMR) circuits with the presence of SEUs. After demonstrating that synchronizing errors cannot be eliminated in such case, this dissertation continues to present novel synchronizer designs that can guarantee reliable synchronization of triplicated signals. Fault injection tests then show that the proposed synchronizers provide between 6 and 10 orders of magnitude longer mean time to failure (MTTF) …

Enhancing Reliability In Passive Anti-Islanding Protection Schemes For Distribution Systems With Distributed Generation, Mohsen Sheikholeslamzadeh

Electronic Thesis and Dissertation Repository

This thesis introduces a new approach to enhance the reliability of conventional passive anti-islanding protection scheme in distribution systems embedding distributed generation. This approach uses an Islanding-Dedicated System (IDS) per phase which will be logically combined with the conventional scheme, either in blocking or permissive modes. Each phase IDS is designed based on data mining techniques. The use of Artificial Neural Networks (ANNs) enables to reach higher accuracy and speed among other data mining techniques. The proposed scheme is trained and tested on a practical radial distribution system with six-1.67 MW Doubly-Fed Induction Generators (DFIG-DGs) wind turbines. Various scenarios of …

Numerical And Reliability Analysis Of Gravity Cantilever Retaining Walls Backfilled With Shredded Tires Subjected To Seismic Loads, Eleanor Huggins

All Theses

Shredded tires have been considered as a suitable alternative to conventional sand and gravel backfill materials as they offer benefits from their significantly lower unit weight, reductions in the cost of materials and construction, and because they utilize a common and potentially hazardous waste material. This research addresses some gaps in previous research in the implementation of shredded tires in this capacity by examining variation in material properties through a reliability analysis, developing an improved design technique for retaining walls tailored to shredded tire fills, and simulating how shredded tire backfill behaves in conjunction with retaining walls when subject to …

Static Balancing Of The Cal Poly Wind Turbine Rotor, Derek Simon

Master's Theses

The balancing of a wind turbine rotor is a crucial step affecting the machine’s performance, reliability, and safety, as it directly impacts the dynamic loads on the entire structure.

A rotor can be balanced either statically or dynamically. A method of rotor balancing was developed that achieves both the simplicity of static balancing and the accuracy of dynamic balancing. This method is best suited, but not limited, to hollow composite blades of any size. The method starts by quantifying the mass and center of gravity of each blade. A dynamic calculation is performed to determine the theoretical shaking force on …

Bayesian Analyses Of Metal-Loss Corrosion On Energy Pipeline Based On Inspection Data, Mohammad Al-Amin

Electronic Thesis and Dissertation Repository

Bayesian models are developed to calibrate the accuracies of high-resolution in-line inspection (ILI) tools for sizing metal-loss corrosion defects and to characterize the growth of individual defects on energy pipelines. Moreover, a methodology is proposed to evaluate the time-dependent system reliability of a segment of a pressurized pipeline containing multiple active corrosion defects. The calibration of ILI tools is carried out by comparing the field-measured depths and ILI-reported depths for a set of static defects. The proposed methodology is able to quantify the measurement errors of multiple ILI tools simultaneously and evaluate the correlation between random errors associated with different …

Uniting The Nation's Power Grids: Opening Markets To Integrate Large Scale Renewable Power, Jeffrey Kenneth Wilkinson

Master's Theses

As renewable energy becomes increasingly cost competitive and Renewable Portfolio Standards (RPS) push states to produce more and more of their steadily growing power demands from renewable sources, the need to solve the problems associated with renewable penetration becomes a priority. The intermittent nature of solar and wind power generation require additional cost that inhibit their implementation as penetration levels grow. Reliability remains power utilities' top priority while they struggle to upgrade their systems. Old generation facilities will be decommissioned, renewable energy projects will come on line and transmission upgrades become inevitable. Variability on the grid is currently mitigated through …

Understanding Design Requirements For Building Reliable, Space-Based Fpga Mgt Systems Based On Radiation Test Results, Kevin M. Ellsworth

Theses and Dissertations

Space-based computing applications often demand reliable, high-bandwidth communication systems. FPGAs with Mulit-Gigabit Transceivers (MGTs) provide an effective platform for such systems, but it is important that system designers understand the possible susceptibilities MGTs present to the system. Previous work has provided a foundation for understanding the susceptibility of raw FPGA MGTs but has fallen short of testing MGTs as part of a larger system. This work focuses on answering the questions MGT system designers need to know in order to build a reliable space-based MGT system. Two radiation tests were performed with a test architecture built on the Aurora protocol. …

Hardware And Software Fault-Tolerance Of Softcore Processors Implemented In Sram-Based Fpgas, Nathaniel Hatley Rollins

Theses and Dissertations

Softcore processors are an attractive alternative to using expensive radiation-hardened processors for space-based applications. Since they can be implemented in the latest SRAM-based FPGA technologies, they are fast, flexible and significantly less expensive. However, unlike ASIC-based processors, the logic and routing of a softcore processor are vulnerable to the effects of single-event upsets (SEUs). To protect softcore processors from SEUs, this dissertation explores the processor design-space for the LEON3 softcore processor implemented in a commercial SRAM-based FPGA. The traditional mitigation techniques of triple modular redundancy (TMR) and duplication with compare (DWC) and checkpointing provide reliability to a softcore processor at …

Design And Characterization Of High Temperature Packaging For Wide-Bandgap Semiconductor Devices, Brian Grummel

Electronic Theses and Dissertations

Advances in wide-bandgap semiconductor devices have increased the allowable operating temperature of power electronic systems. High-temperature devices can benefit applications such as renewable energy, electric vehicles, and space-based power electronics that currently require bulky cooling systems for silicon power devices. Cooling systems can typically be reduced in size or removed by adopting wide-bandgap semiconductor devices, such as silicon carbide. However, to do this, semiconductor device packaging with high reliability at high temperatures is necessary. Transient liquid phase (TLP) die-attach has shown in literature to be a promising bonding technique for this packaging need. In this work TLP has been comprehensively …

Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe

Electronic Theses and Dissertations

Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …

A Fault-Tolerant Alternative To Lockstep Triple Modular Redundancy, Andrew Lockett Baldwin

Dissertations and Theses

Semiconductor manufacturing defects adversely affect yield and reliability. Manufacturers expend vast resources to reduce defects within their processes. As the minimum feature size get smaller, defects become increasingly difficult to prevent. Defects can change the behavior of a logic circuit resulting in a fault. Manufacturers and designers may improve yield, reliability, and profitability by using design techniques that make products robust even in the presence of faults. Triple modular redundancy (TMR) is a fault tolerant technique commonly used to mask faults using voting outcomes from three processing elements (PE). TMR is effective at masking errors as long as no more …

Reactive Power Considerations In Reliability Analysis Of Solar Photovoltaic Systems, Dattatray N. Gaikwad

LSU Master's Theses

Reliability is one of the key aspects of power system operation and therefore reliability analysis techniques are well developed. However reliability analysis conventionally takes into account active power and limited attention has been given to reactive power. Reactive power is very essential in maintaining voltage stability of power systems. The voltage constraint at network can restricts active power delivery to the loads and could result in forced load curtailment. This research investigates the effect of reactive power shortage on reliability of power systems with significant penetration of PV cells. The reactive power issues become more significant in distributed generation using …