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FAULT RESILIENT INTEGRATION OF RENEWABLE SOURCES AND DERS IN SMART GRIDS
No full textThesis (Ph.D.), Electrical Engineering, Washington State UniversitySmart grids, which are alternatively called by many researchers as “Grids of the future” have attracted a lot of attention the recent years. Two key features that enable practical implementation of smart grids are, Condition Monitoring (CM) and advanced control techniques. Internal or external faults seen by Distributed Energy Resources (DERs), however, can adversely impact the reliability of the smart grids and hinder the rapid rate of their implementation.
Traditionally, the internal faults were detected and isolated using either model-based or data-driven techniques. Owing to accurate models that were derived for the power components, model-based method’s utilization has grown substantially and outpaced the data-driven methods. However, one major shortcoming of model-based methods is their inefficiency in dealing with components that are composed of several physical and dynamical domains (i.e. mechanical, electrical, chemical, etc.). To remedy this shortcoming, initially in this dissertation, a model-based CM method for DERs, evolved from Bond-graph theory is proposed. The proposed method is suitable for dealing with multi-physics systems. Moreover, the proposed CM method is extended to consider the uncertainties that are caused by noisy measurements (sensor uncertainty) and lack of accurate information about the DER parameter values (parameter uncertainty).
With higher penetration of DERs in the smart grids, utility grids have developed certain requirements (also known as grid codes) to regulate the interconnection of the generating sources. One of the major requirements in the grid codes concern about the behavior of DERs under external faults and when experiencing voltage sags. The conventional controllers are designed to show fast response since they are tuned to operate in normal conditions. However, during a voltage sag, it is vital for the controller to show an over-damped response to meet the grid codes. Hence, in the second portion of this dissertation, a controller is that is capable of showing fast response during normal condition and an over-damped response during voltage sags. The proposed controller can be perceived as extensions to the well-known Sliding-mode and PID controller. The proposed controller is applied successfully to Fuel Cell and Solar panel DERs under symmetrical and unsymmetrical voltage sages.Washington State University, Electrical EngineeringBy student request, this dissertation cannot be exposed to search engines and is, therefore, only accessible to Washington State University users
SPECTRAL MODEL OF RESONANT SOFT X-RAY SCATTERING TO RESOLVE MOLECULE SPECIFIC ORGANIZATION IN 3D ORGANIC NANOSTRUCTURES
No full textThesis (Ph.D.), Physics, Washington State UniversityInterest in developing carbon-based materials has increased in recent years due to their advantageous structure and properties. One common challenge in all potential applications is understanding how morphology, in addition to molecular structure, governs the properties and performance. Advances with resonant soft X-ray scattering (RSOXS) have begun to surpass limitations of traditional nanostructure probes that are reliant on electron density contrast alone. RSOXS exhibits enhanced sensitivity to chemical structure through core-shell interactions but, to date, have only provided qualitative descriptions of nanostructures. This dissertation details the development of quantitative spectral modeling of RSOXS to resolve chemical specific organization in organic thin films. Multiphase scattering theory is combined with continuous contrast tuning at the carbon absorption edge to identify origins of scattering and highlight signal from material domains. Additionally, a novel secondary calibration of absolute scattering is developed utilizing X-ray fluorescence of a carbon standard film that allows for a quantitative measurement of RSOXS intensity. Optical models are first demonstrated with a measurement of the scattering invariant on block copolymer assemblies of poly(styrene-block-methyl methacrylate). By isolating scattering from molecular domains, the width of the mixed interfacial region is determined in a series of assembled 3D nanostructures and is found to agree with Flory-Huggins theory. Developed optical models are then combined with X-ray diffraction to quantify the nano-mesoscale morphology of poly(3-hexylthiophene):Phenyl-C61-Butyric acid methyl ester organic photovoltaics. In this follow-up study, a suit of opto-electronic measurements is conducted to rigorously explore a step-by-step characterization of the fundamental charge generation process that occurs within these devices. When paired with the previously developed morphological analysis a direct correlation between nanostructure and electronic properties is established. It was found that the efficiency of charge transfer state separation, as measured on real devices with time-delayed collection field, anti-correlates with the volume of the interfacial mixed phase. These results provide experimental evidence toward an ideal morphology that contains a limited interfacial mixed domain with the necessary energetic landscape for charge generation. The quantitative spectral analysis developed in this work enables RSOXS to identify and characterize a potentially limitless number of unique molecular species in complex organic nanostructures.Washington State University, PhysicsBy student request, this dissertation cannot be exposed to search engines and is, therefore, only accessible to Washington State University users
Field equipment for grain production on modest acreages and diversified farm operations
No full textThis Extension manual provides an introduction to grain production equipment appropriate for small- and medium-scale farmers new to grain growing as well as considerations for sourcing affordable and reliable farming implements. It also incorporates the experience of farmers and tractor mechanics who have grown small grains for many years, worked on small grain equipment, or have direct, recent experience adding grain enterprises to diversified farm operations. Topics addressed in this manual include equipment needed to add a grain enterprise (1), a review of production equipment from field preparation to harvest (2), considerations for equipment selection (3), and sourcing grain production equipment (4). This publication focuses mostly on used and older equipment considering that many diversified farms, and those operating on modest acreages, cannot afford to invest in new and larger-scale grain production equipment
