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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Practice Summary: Improved Reliability via Optimization in Residential Microgrids

Southern Company is an electric utility that is embracing residential microgrids as a platform for distributed energy. The first residential microgrid in the southeastern United States was constructed in Hoover, Alabama, as a testbed for development. To operate the microgrid, we developed an optimization model for unit commitment and economic dispatch. We report the optimization model was implemented in a microgrid central controller and tested under various operational scenarios. Challenges also include developing a pricing algorithm to deliver price forecasts to the residential homes in the microgrid and open-source software restrictions.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Methodology Development for Passive Component Reliability Modeling in a Multi-Physics Simulation Environment

Reduction in safety margin can be expected as passive structures and components undergo degradation with time. Limitations in the traditional probabilistic risk assessment (PRA) methodology constrain its value as an effective tool to address the impact of aging effects on risk and for quantifying the impact of aging management strategies in maintaining safety margins. A methodology has been developed to address multiple aging mechanisms involving large numbers of components (with possibly statistically dependent failures) within the PRA framework in a computationally feasible manner when the sequencing of events is conditioned on the physical conditions predicted in a simulation environment, such as the New Generation System Code (NGSC) concept. Both epistemic and aleatory uncertainties can be accounted for within the same phenomenological framework and maintenance can be accounted for in a coherent fashion. The framework accommodates the prospective impacts of various intervention strategies such as testing, maintenance, and refurbishment. The methodology is illustrated with several examples.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2015

Embedded Sensors and Controls to Improve Component Performance and Reliability -- Bench-scale Testbed Design Report

Embedded instrumentation and control systems that can operate in extreme environments are challenging due to restrictions on sensors and materials. As a part of the Department of Energy's Nuclear Energy Enabling Technology cross-cutting technology development programs Advanced Sensors and Instrumentation topic, this report details the design of a bench-scale embedded instrumentation and control testbed. The design goal of the bench-scale testbed is to build a re-configurable system that can rapidly deploy and test advanced control algorithms in a hardware in the loop setup. The bench-scale testbed will be designed as a fluid pump analog that uses active magnetic bearings to support the shaft. The testbed represents an application that would improve the efficiency and performance of high temperature (700 C) pumps for liquid salt reactors that operate in an extreme environment and provide many engineering challenges that can be overcome with embedded instrumentation and control. This report will give details of the mechanical design, electromagnetic design, geometry optimization, power electronics design, and initial control system design.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2016

Embedded Sensors and Controls to Improve Component Performance and Reliability -- Loop-scale Testbed Design Report

Embedded instrumentation and control systems that can operate in extreme environments are challenging to design and operate. Extreme environments limit the options for sensors and actuators and degrade their performance. Because sensors and actuators are necessary for feedback control, these limitations mean that designing embedded instrumentation and control systems for the challenging environments of nuclear reactors requires advanced technical solutions that are not available commercially. This report details the development of testbed that will be used for cross-cutting embedded instrumentation and control research for nuclear power applications. This research is funded by the Department of Energy's Nuclear Energy Enabling Technology program's Advanced Sensors and Instrumentation topic. The design goal of the loop-scale testbed is to build a low temperature pump that utilizes magnetic bearing that will be incorporated into a water loop to test control system performance and self-sensing techniques. Specifically, this testbed will be used to analyze control system performance in response to nonlinear and cross-coupling fluid effects between the shaft axes of motion, rotordynamics and gyroscopic effects, and impeller disturbances. This testbed will also be used to characterize the performance losses when using self-sensing position measurement techniques. Active magnetic bearings are a technology that can reduce failures and maintenance costs in nuclear power plants. They are particularly relevant to liquid salt reactors that operate at high temperatures (700 C). Pumps used in the extreme environment of liquid salt reactors provide many engineering challenges that can be overcome with magnetic bearings and their associated embedded instrumentation and control. This report will give details of the mechanical design and electromagnetic design of the loop-scale embedded instrumentation and control testbed.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Ensuring Reliable Natural Gas-Fired Power Generation with Fuel Contracts and Storage

This report finds that natural gas-fired power plants purchase fuel both on the spot market and through firm supply contracts; there do not appear to be clear drivers propelling power plants toward one or the other type. Most natural gas-fired power generators are located near major natural gas transmission pipelines, and most natural gas contracts are currently procured on the spot market. Although there is some regional variation in the type of contract used, a strong regional pattern does not emerge. Whether gas prices are higher with spot or firm contracts varies by both region and year.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2019

Metal Bellows Valve Reliability Testing

Swagelok B ® series metal bellows-sealed valves were tested for their cycle performance longevity to evaluate their use in tritium service. The valves selected differed in the size of their pneumatic actuator and the stem tip material. Valves tested had one of three actuator sizes (1C, 3C, or 5C) and one of two stem tip materials: a cobalt-based metal, Stellite™, and a polyimide material, Vespel ® . An automated valve manifold was constructed, allowing for the simultaneous cycling of a total of 10 valves. Automation controls allowed for user inputs, controlling the number of valve cycles per test and the number of tests per experiment. Valves installed on the valve testing manifold to be cycled following a valve frequency test plan. After a defined number cycles, the valves would undergo leak testing using an inline leak detector. The inline helium leak detector provided qualitative detection of any failing or failed valves. If a valve had failed, a leak rate greater than at 1.0 x 10 -7 std cc He/sec, the valve would be removed from the manifold and quantitative leak rate measurements made. After specific cycling milestones were reached, quantitative valve leak rate measurements were performed to assess the adequacy of the qualitative measurement method. Valve evaluation began with initial leak tests: valve inlet/outlet seat rates and total body leak rate. The as received 1C valves, with PTFE stem tips, passed initial leak tests; however, stem tips replacements with either metal or polyimide stem tips essentially created valves which failed subsequent leak tests and were not subject to valve cycling. The 3C actuated valves had been cycled 150,000 times, resulting in 60% of the Stellite™ and Vespel ® tipped valves still passing the leak rate criteria. Failure analysis on the other 40% has yet to be conducted. Eight of the 5C valves had reached 150,000 cycles with 80% of the valves passing the leak rate criteria: two Vespel ® tipped 5C valves failed leak rate testing after 120,000 cycles.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Emergency Diesel Generator Reliability and Installation Energy Security

The U.S. Department of Defense’s (DoD’s) fixed installations - or military bases - are a critical element of national security. Military bases support the maintenance and deployment of weapons systems, training and mobilization of combat forces, and provide direct support to combat operations. Fixed installations do not operate without energy and they rely largely on electricity to support critical missions and functions. Installations are dependent on a commercial grid that is vulnerable to disruption due to severe weather, physical attacks, and cyberattacks. This report looks at the impact on the highest priority critical loads.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

A High-Voltage High-Reliability Scalable Architecture for Electric Vehicle Power Electronics (Final Report)

This project developed and demonstrated new composite converter technologies that lead to high power density (> 20 kW/L) at power levels of 10s of kW, 100s of kW, or possibly higher, with fundamental advances in converter efficiency and Q that lead to substantial increases in mean time to failure (MTTF). These advantages were realized through development of new composite converter topologies that perform buck, boost, or other conversion functions and that are scalable to higher voltage and power levels through sharing of voltage and current stresses among multiple dissimilar partial-power converter modules. The project led to experimental demonstration of a125 kW multifunction electric vehicle power conversion system having in-creased dc bus voltage (950 V nominal, 1200 V peak) that interfaces a 200 V to 400 V battery pack, and that includes integrated level 2 wired charging and wireless charging functions. The project incorporated SiC MOSFET modules having switching frequencies in excess of 100 kHz, planar magnetics, a hierarchical control architecture that enables scaling to higher voltages and powers with additional converter modules, and a high-power density in excess of 20 kW/L. The research demonstrated how a more complex converter approach can increase mean-time-to-failure, even though the number of elements is increased. This is achieved through significant reduction of temperature rise through fundamentally superior converter circuit topologies. The research also demonstrated new high power planar magnetics that increase power density. The technology is appropriate to a variety of applications including EV power trains, EV charging, PV inverters, battery storage, and similar areas. These systems potentially can be manufactured in the U.S.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2026

Shelter Island, New York, Energy Reliability Assessment and Local Generation Options

Shelter Island's Green Options Committee (GOC), an all-volunteer committee tasked with considering all environmental conservation issues, requested technical assistance under the U.S. Department of Energy (DOE)-funded Energy Technology Innovation Partnership Project (ETIPP). The primary goals of this technical assistance project included: 1. Informing the GOC about energy use trends within the community as well as distributed solar, wind and storage opportunities; 2. Providing additional resources and technical feasibility information for geothermal, agrivoltaics and tidal energy; 3. Supporting the development of a community engagement plan; and 4. Supporting collaboration between the GOC and PSEG in order to find mutually beneficial follow-on projects. Assistance from NLR to help the GOC meet these overall project goals was provided through the following primary tasks: 1. Collaborate with the local utility in order to collect energy use data and inform the community on energy use patterns through a baseline assessment; 2. Technical analysis of distributed renewable and resiliency opportunities (solar, wind and storage) that best align with the community's energy priorities; 3. Provide high level feasibility support for future renewable energy scenarios that include agrivoltaic solutions, tidal energy, and geothermal projects on Shelter Island, and 4. Integrate all findings into a Community Outreach presentation to help the GOC engage with community stakeholders to build support and awareness of chosen resilience strategies.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2026

2025 InterPACK: Thermal Management and Reliability Aspects

The presentation will provide an overview of automotive power electronics and electric machines thermal management systems that are typical for light-duty vehicles. Unique thermal and environmental aspects related to medium and heavy-duty vehicle applications will then be discussed. Finally, advanced thermal management and packaging technologies that could be evaluated and used in this project will be described.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2026

Field Verification of Grid-Forming Inverter-Based Power Plant Performance for Transmission System Reliability

This report describes some examples of the operation of two grid-forming (GFM) inverter-based photovoltaic-battery hybrid power plants connected to the electric system of the island of Kauai in Hawaii. Both plants are photovoltaic power plants with battery energy storage and are connected to the networked transmission system operated by Kauai Island Utility Cooperative (KIUC), along with several other power plants including an oil-fired plant, diesel generators, small hydroelectric plants, a biofuel plant, and several other photovoltaic plants.

14 SOLAR ENERGY↗
DOE OSTI2015

Quantifying Reliability - The Next Step for a Rapidly Maturing PV Industry and China's Role

PV customers wish to know how long their PV modules will last, but quantitatively predicting service life is difficult because of the large number of ways that a module can fail, the variability of the use environment, the cost of the testing, and the short product development time, especially when compared with the long desired lifetime. China should play a key role in developing international standards because China manufactures most of the world's PV modules. The presentation will describe the steps that need to be taken to create a service life prediction within the context of a defined bill of materials, process window and use environment. Worldwide standards for cost-effective approaches to service-life predictions will be beneficial to both PV customers and manufacturers since the consequences of premature module failure can be disastrous for both.

14 SOLAR ENERGY↗
DOE OSTI2017

PV Reliability -- Where We've Been and Where We're Going

The photovoltaic (PV) industry has demonstrated impressive progress toward deploying hardware with excellent quality. As module prices drop and designs are squeezed to reduce cost of materials and processing, how will this affect the failures that are seen in the field?

14 SOLAR ENERGY↗