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At least 1,387 records · Page 77

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DOE OSTI2026

Evaluating Protection System Performance for a Real-World Weak Grid Area With High Inverter-Based Resources

This paper evaluates an existing protection scheme implemented in a real-world weak grid area with a high penetration of inverter-based resources (IBRs). The study aims to assess the reliability and adequacy of protection schemes originally designed for traditional synchronous machine systems and determine whether they can continue to operate reliably in systems with high levels of IBRs. Hardware relays are tested using a controller-hardware-in-the-loop setup. PSCAD electromagnetic transient simulation with an IBR original equipment manufacturer black-box model is used to perform fault studies and generate COMTRADE data, which are replayed by a realtime digital simulator (RTDS) to feed input to the hardware relays. Three scenarios are analyzed: normal operation, an N-1 contingency, and an IBR-only scenario. The evaluation results reveal the following: 1) the protection scheme remains reliable under normal conditions and N-1 contingencies and 2) in IBRonly scenarios, differential protection (87L) continues to operate reliably, whereas local protection elements, such as distance and directional elements, fail because of the lack of regulated negative sequence current contributed by IBRs. These findings provide utilities with valuable insights for improving their protection systems in high-IBRs.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2014

A system for trapping barium ions in a microfabricated surface trap

We have developed a vacuum chamber and control system for rapid testing of microfabricated surface ion traps. Our system is modular in design and is based on an in-vacuum printed circuit board with integrated filters. We have used this system to successfully trap and cool barium ions and have achieved ion ‘dark' lifetimes of 31.6 s ± 3.4 s with controlled shuttling of ions. We provide a detailed description of the ion trap system including the in-vacuum materials used, control electronics and neutral atom source. We discuss the challenges presented in achieving a system which can work reliably over two years of operations in which the trap under test was changed at least 10 times.

43 PARTICLE ACCELERATORS↗

DOE OSTI2017

Establishment of a PID Pass/Fail Test for Crystalline Silicon Modules by Examining Field Performance for Five Years: Preprint

In an experiment with five module designs and multiple replicas, it is found that crystalline silicon cell modules that can pass a criterion of less than 5 percent power degradation in stress test conditions of 60 degrees Celsius, 85 percent relative humidity (RH), 96 h, and nameplate-rated system voltage bias show no power degradation by potential induced degradation in the range of 4-6 years duration in the Florida, USA environment. This data suggests that this chamber stress level is useful as a pass/fail criterion for PID, and will help ensure against degradation by system voltage stress in Florida, or less stressful climates, for at least 5 years.

14 SOLAR ENERGY↗

DOE OSTI2022

Extreme events, energy security and equality through micro- and macro-levels: Concepts, challenges and methods

Low-income households face long-standing challenges of energy insecurity and inequality (EII). During extreme events (e.g., disasters and pandemics) these challenges are especially severe for vulnerable populations reliant on energy for health, education, and well-being. However, many EII studies rarely incorporate the micro- and macro-perspectives of resilience and reliability of energy and internet infrastructure and social-psychological factors. To remedy this gap, we first address the impacts of extreme events on EII among vulnerable populations. Second, we evaluate the driving factors of EII and how they change during disasters. Third, we situate these inequalities within broader energy systems and pinpoint the importance of equitable infrastructure systems by examining infrastructure reliability and resilience and the role of renewable technologies. Then, we consider the factors influencing energy consumption, such as energy practices, socio-psychological factors, and internet access. Finally, we propose interdisciplinary research methods to study these issues during extreme events and provide recommendations.

Chen, CF↗

DOE OSTI2026

Evaluating Protection System Performance for a Real-World Weak Grid Area With High Inverter-Based Resources: Preprint

This paper evaluates an existing protection scheme implemented in a real-world weak grid area with a high penetration of inverter-based resources (IBRs). The study aims to assess the reliability and adequacy of protection schemes originally designed for traditional synchronous machine systems and determine whether they can continue to operate reliably in systems with high levels of IBRs. Hardware relays are tested using a controller-hardware-in-the-loop setup. PSCAD electromagnetic transient simulation with an IBR original equipment manufacturer black-box model is used to perform fault studies and generate COMTRADE data, which are replayed by a real-time digital simulator (RTDS) to feed input to the hardware relays. Three scenarios are analyzed: normal operation, an N-1 contingency, and an IBR-only scenario. The evaluation results reveal the following: 1) the protection scheme remains reliable under normal conditions and N-1 contingencies and 2) in IBR-only scenarios, differential protection (87L) continues to operate reliably, whereas local protection elements, such as distance and directional elements, fail because of the lack of regulated negative sequence current contributed by IBRs. These findings provide utilities with valuable insights for improving their protection systems in high-IBRs.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2024

Development and Validation of a Scoring System for Abnormalities in the Gopher Frog (Rana capito)

Headstarting efforts are thought to be critical in supplementing populations of the at-risk Gopher Frog (Rana capito); however, recent efforts have occasionally resulted in juveniles with developmental abnormalities. In response, we developed a scoring system to collect quantitative data on the presence and severity of these developmental abnormalities. Our objective was to describe and validate the abnormality scoring system so that it can be used by all Gopher Frog headstarting facilities. The scoring system covers five primary conditions encompassing commonly observed abnormalities. Two groups of participants with different levels of prior experience working with Gopher Frogs assigned scores to a set of images presented to them for each condition. We used intra-class correlation coefficients (ICC) to test the scoring system for inter- and intra-rater agreement as well as agreement with the benchmark standard (established by the authors). We found high ICC values for inter-rater agreement, intra-rater agreement, and agreement to the benchmark standard indicating either excellent or good reliability for all five conditions and for all raters when grouped together. These findings support the reliability and validity of the proposed developmental abnormality scoring system. Gopher Frog headstarting facilities can implement this scoring system to assist in tracking the frequency and severity of abnormalities observed in future headstarting efforts. We hope that by creating a reliable scoring system for Gopher Frogs, it can provide an overall framework and serve as a valuable resource to evaluate abnormalities across any amphibian species.

abnormality↗

DOE OSTI2022

2022 Peer Review Project Summary: Advanced Protection for Microgrids and DER in Secondary Networks and Meshed Distribution Systems

Although there are increasing numbers of distributed energy resources (DERs) and microgrids being deployed, current IEEE and utility standards generally strictly limit their interconnection inside secondary networks. Secondary networks are low-voltage meshed (non-radial) distribution systems that create redundancy in the path from the main grid source to each load. This redundancy provides a high level of immunity to disruptions in the distribution system, and thus extremely high reliability of electric power service. There are two main types of secondary networks, called grid and spot secondary networks, both of which are used worldwide. In the future, primary networks in distribution systems that might include looped or meshed distribution systems at the primary-voltage (mediumvoltage) level may also become common as a means for improving distribution reliability and resilience. The objective of this multiyear project is to increase the adoption of microgrids in secondary networks and meshed distribution systems by developing novel protection schemes that allow for safe reliable operation of DERs in secondary networks. We will address these challenges by working with the appropriate stakeholders of secondary network operators, protection vendors, and standards committee. The outcomes of this project include: a) development and/or demonstration of candidate methods for enabling protection of secondary networks containing high levels of DER; b) development of modeling and testing tools for protection systems designed for use with secondary networks including DERs; and c) development of new industrial partnerships to facilitate widespread results dissemination and eventual commercialization of results as appropriate.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2017

Decentralized State Estimation and Remedial Control Action for Minimum Wind Curtailment Using Distributed Computing Platform

Intermittency of wind energy poses a great challenge for power system operation and control. Wind curtailment might be necessary at the certain operating condition to keep the line flow within the limit. Remedial Action Scheme (RAS) offers quick control action mechanism to keep reliability and security of the power system operation with high wind energy integration. In this paper, a new RAS is developed to maximize the wind energy integration without compromising the security and reliability of the power system based on specific utility requirements. A new Distributed Linear State Estimation (DLSE) is also developed to provide the fast and accurate input data for the proposed RAS. A distributed computational architecture is designed to guarantee the robustness of the cyber system to support RAS and DLSE implementation. The proposed RAS and DLSE is validated using the modified IEEE-118 Bus system. Simulation results demonstrate the satisfactory performance of the DLSE and the effectiveness of RAS. Real-time cyber-physical testbed has been utilized to validate the cyber-resiliency of the developed RAS against computational node failure.

17 WIND ENERGY↗

DOE OSTI2014

Validation of Kepler's multiple planet candidates. II. Refined statistical framework and descriptions of systems of special interest

We extend the statistical analysis performed by Lissauer et al. in 2012, which demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) represents true transiting planets, and we develop therefrom a procedure to validate large numbers of planet candidates in multis as bona fide exoplanets. We show that this statistical framework correctly estimates the abundance of false positives already identified around Kepler targets with multiple sets of transit-like signatures based on their abundance around targets with single sets of transit-like signatures. We estimate the number of multis that represent split systems of one or more planets orbiting each component of a binary star system. We use the high reliability rate for multis to validate more than one dozen particularly interesting multi-planet systems herein. Hundreds of additional multi-planet systems are validated in a companion paper by Rowe et al. We note that few very short period (P < 1.6 days) planets orbit within multiple transiting planet systems and discuss possible reasons for their absence. There also appears to be a shortage of planets with periods exceeding a few months in multis.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2022

Welcome to the Special Issue on Grid-Edge Computing With Behind-the-Meter Resources [Guest Editorial]

The integration of distributed energy resources (DERs), such as solar photovoltaic systems, as well as other synergistic assets, including electric vehicles, energy storage, and smart appliances, in electric power systems has been dramatically increasing in the past few years. These assets have the capability to provide much-needed flexibility to electric power systems for improved grid reliability, resilience, and economic efficiency; however, most of these resources are located behind the meter (BTM) on customer premises, and their flexibility is not fully used in current grid operations. Grid-edge computing plays an important role in unlocking the great benefits and potential that BTM resources could provide to electric power systems by enhancing visibility and controllability at the grid edge.

behind-the-meter resources↗

DOE OSTI2020

Domestic Hot Water Temperature Maintenance Technology Review

Domestic hot water temperature maintenance (HWTM) is an important topic in facility management, and there are often opportunities to optimize systems to achieve energy, water, and maintenance savings. The main purpose of an HWTM system is to provide reliable hot water temperature at all fixtures with minimal wait time. This is done by replacing the standby heat losses from hot water sitting idle in pipes during periods of low demand. Traditionally, most commercial buildings do this by having water recirculate back to the water heater to be reheated. Other currently available HWTM systems are also discussed in this resource. HWTM systems can help maintain water at appropriate temperatures, minimize heat loss, and minimize delivery times to fixtures to improve the function of a building. This webpage includes a summary of HWTM options along with important considerations regarding occupant safety and comfort, and maintenance strategies for optimal and efficient operations. Domestic hot water (DHW) generation systems are referred to but are not the focus of this resource.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2023

On the potentially transformative role of auxiliary-field quantum Monte Carlo in quantum chemistry: A highly accurate method for transition metals and beyond

Approximate solutions to the ab initio electronic structure problem have been a focus of theoretical and computational chemistry research for much of the past century, with the goal of predicting relevant energy differences to within “chemical accuracy” (1 kcal/mol). For small organic molecules, or in general, for weakly correlated main group chemistry, a hierarchy of single-reference wave function methods has been rigorously established, spanning perturbation theory and the coupled cluster (CC) formalism. For these systems, CC with singles, doubles, and perturbative triples is known to achieve chemical accuracy, albeit at O(N7) computational cost. In addition, a hierarchy of density functional approximations of increasing formal sophistication, known as Jacob’s ladder, has been shown to systematically reduce average errors over large datasets representing weakly correlated chemistry. However, the accuracy of such computational models is less clear in the increasingly important frontiers of chemical space including transition metals and f-block compounds, in which strong correlation can play an important role in reactivity. A stochastic method, phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC), has been shown to be capable of producing chemically accurate predictions even for challenging molecular systems beyond the main group, with relatively low O(N3 − N4) cost and near-perfect parallel efficiency. Herein, we present our perspectives on the past, present, and future of the ph-AFQMC method. We focus on its potential in transition metal quantum chemistry to be a highly accurate, systematically improvable method that can reliably probe strongly correlated systems in biology and chemical catalysis and provide reference thermochemical values (for future development of density functionals or interatomic potentials) when experiments are either noisy or absent. Finally, we discuss the present limitations of the method and where we expect near-term development to be most fruitful.

Chemistry↗

DOE OSTI2015

SU-E-J-211: Assessing the Consistency of the ViewRay 0.35 T MRI System

Purpose: ViewRay is a novel image-guided radiotherapy approach with an integrated 0.35 T MR unit and three Cobalt-60 heads. In order to continuously ensure the high resolution and high soft tissue contrast available in MR images, we quantified a multitude of relevant imaging parameters over a period of six months to establish its stability and imaging quality. In the assessment process, consideration is also given to the need to establish the number of tests required to have confidence in the performance of the system for radiation therapy planning applications. Methods: Daily, weekly, monthly and annual imaging tests were performed over a period of six months using standardized phantoms (a 24 cm diameter sphere and the ACR phantom) to quantify the performance of the system. In addition to the ACR and NEMA recommended tests, we also included element testing, spatial integrity, Eddy current and magnetic field inhomogeneity measurements. The ACR test is used for assessing the following parameters for T1 and T2: geometric accuracy, high contrast spatial resolution, slice thickness accuracy, slice position accuracy, percent signal ghosting, low contrast object detectability. It also includes percent image uniformity (PIU) for T1. The NEMA test is primarily designed to check SNR and PIU. Results: Over the period of six months, all the parameters were maintained within the recommendations provided in the ACR and NEMA standards. PIU and SNR were found to be sensitive to malfunctions in the components of the multileaf collimators. Details of the findings will be presented. Conclusion: The data suggests that ViewRay imaging system has functioned in a consistent and reliable manner. MR imaging from ViewRay 0.35T system complies with the ACR and NEMA recommended acceptance standards.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2013

Long-Term Instrumentation, Information, and Control Systems (II&C) Modernization Future Vision and Strategy

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2013

Long-Term Instrumentation, Information, and Control Systems (II&C) Modernization Future Vision and Strategy

Life extension beyond 60 years for the U.S operating nuclear fleet requires that instrumentation and control (I&C) systems be upgraded to address aging and reliability concerns. It is impractical for the legacy systems based on 1970’s vintage technology operate over this extended time period. Indeed, utilities have successfully engaged in such replacements when dictated by these operational concerns. However, the replacements have been approached in a like-for-like manner, meaning that they do not take advantage of the inherent capabilities of digital technology to improve business functions. And so, the improvement in I&C system performance has not translated to bottom-line performance improvement for the fleet. Therefore, wide-scale modernization of the legacy I&C systems could prove to be cost-prohibitive unless the technology is implemented in a manner to enable significant business innovation as a means of off-setting the cost of upgrades. A Future Vision of a transformed nuclear plant operating model based on an integrated digital environment has been developed as part of the Advanced Instrumentation, Information, and Control (II&C) research pathway, under the Light Water Reactor (LWR) Sustainability Program. This is a research and development program sponsored by the U.S. Department of Energy (DOE), performed in close collaboration with the nuclear utility industry, to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. DOE’s program focus is on longer-term and higher-risk/reward research that contributes to the national policy objectives of energy security and environmental security . The Advanced II&C research pathway is being conducted by the Idaho National Laboratory (INL). The Future Vision is based on a digital architecture that encompasses all aspects of plant operations and support, integrating plant systems, plant work processes, and plant workers in a seamless digital environment to enhance nuclear safety, increase productivity, and improve overall plant performance. The long-term goal is to transform the operating model of the nuclear power plants (NPP)s from one that is highly reliant on a large staff performing mostly manual activities to an operating model based on highly integrated technology with a smaller staff. This digital transformation is critical to addressing an array of issues facing the plants, including aging of legacy analog systems, potential shortage of technical workers, ever-increasing expectations for nuclear safety improvement, and relentless pressure to reduce cost. The Future Vision is based on research is being conducted in the following major areas of plant function: 1. Highly integrated control rooms 2. Highly automated plant 3. Integrated operations 4. Human performance improvement for field workers 5. Outage safety and efficiency. Pilot projects will be conducted in each of these areas as the means for industry to collectively integrate these new technologies into nuclear plant work activities. The pilot projects introduce new digital technologies into the nuclear plant operating environment at host operating plants to demonstrate and validate them for production usage. In turn, the pilot project technologies serve as the stepping stones to the eventual seamless digital environment as described in the Future Vision.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2015

Mexico and the 21st Century Power Partnership (Fact Sheet)

The 21st Century Power Partnership's program in Mexico (21CPP Mexico) is one initiative of the Clean Energy Ministerial, carried out in cooperation with government and local stakeholders, drawing upon an international community of power system expertise. The overall goal of this program is to support Mexico's power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon system. 21CPP Mexico activities focus on achieving positive outcomes for all participants, especially addressing critical questions and challenges facing policymakers, regulators, and system operators. In support of this goal, 21CPP Mexico taps into deep networks of expertise and professional connections.

21ST CENTURY POWER↗

DOE OSTI2016

Mexico and the 21st Century Power Partnership: Paving the Way to a Greener, Smarter, More Flexible Grid

The 21st Century Power Partnership's program in Mexico (21CPP Mexico) is one initiative of the Clean Energy Ministerial carried out in cooperation with government and local stakeholders, drawing upon an international community of power system expertise.The overall goal of this program is to support Mexico's power system transformation by accelerating the transition to a reliable, financially robust, and low-carbon system.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2013

High Reliability R-10 Windows Using Vacuum Insulating Glass Units

The objective of this effort was for EverSealed Windows (“EverSealed” or “ESW”) to design, assemble, thermally and environmentally test and demonstrate a Vacuum Insulating Glass Unit (“VIGU” or “VIG”) that would enable a whole window to meet or exceed the an R-10 insulating value (U-factor ≤ 0.1). To produce a VIGU that could withstand any North American environment, ESW believed it needed to design, produce and use a flexible edge seal system. This is because a rigid edge seal, used by all other know VIG producers and developers, limits the size and/or thermal environment of the VIG to where the unit is not practical for typical IG sizes and cannot withstand severe outdoor environments. The rigid-sealed VIG’s use would be limited to mild climates where it would not have a reasonable economic payback when compared to traditional double-pane or triple-pane IGs. ESW’s goals, in addition to achieving a sufficiently high R-value to enable a whole window to achieve R-10, included creating a VIG design that could be produced for a cost equal to or lower than a traditional triple-pane IG (low-e, argon filled). ESW achieved these goals. EverSealed produced, tested and demonstrated a flexible edge-seal VIG that had an R-13 insulating value and the edge-seal system durability to operate reliably for at least 40 years in the harshest climates of North America.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗