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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 163 records · Page 9

Distributed Cooperative Control of Hybrid AC/DC Microgrid

This paper presents a distributed cooperative control-based power management algorithm for a hybrid AC/DC microgrid. The proposed algorithm for a hybrid microgrid system controls the power flow through the interface converter between the AC and DC microgrids. This algorithm allows power sharing between the distributed generators in the microgrid according to their power ratings. Moreover, it enables the fixed scheduled power delivery through the interface converters in both directions at different operating conditions while maintaining voltage regulation and improving the frequency profile. The effectiveness of the controller is confirmed by simulation.

24 POWER TRANSMISSION AND DISTRIBUTION↗

A valuation framework for customers impacted by extreme temperature-related outages

Extreme temperature outages can lead to not just economic losses but also various non-energy impacts (NEI), such as increased mortality rates, property damage, and reduced productivity, due to significant degradation of indoor operating conditions caused by service disruptions. However, existing resilience assessment approaches lack specificity for extreme temperature conditions. They often overlook temperature-related mortality and neglect the customer characteristics and grid response in the calculation, despite the significant influence of these factors on NEI-related economic losses. This paper aims to address these gaps by introducing a comprehensive framework to estimate the impact of resilience enhancement not only on the direct economic losses incurred by customers but also on potential NEI, including mortality and the value of statistical life during extreme temperature-related outages. The proposed resilience valuation integrates customer characteristics and grid response variables based on a scalable grid simulation environment. This study adopts a holistic approach to quantify customer-oriented economic impacts, utilizing probabilistic loss scenarios that incorporate health-related factors and damage/loss models as a function of exposure for valuation. The proposed methodology is demonstrated through comparative resilient outage planning, using grid response models emulating a Texas weather zone during the 2021 winter storm Uri. The case study results show that enhanced outage planning with hardened infrastructure can improve the system resilience and thereby reduce the relative risk of mortality by 16% and save the total costs related to non-energy impacts by 74%. In conclusion, these findings underscore the efficacy of the framework by assessing the financial implications of each case, providing valuable insights for decision-makers and stakeholders involved in extreme-weather related resilience planning for risk management and mitigation strategies.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Autonomous Voltage Response for Distributed Energy Resources

An implementation of stable droop voltage response for distributed energy resources (DER) is described. The key point is to use a new “autonomously adjusting reference voltage” as described in IEEE Standard 1547-2018. Examples include battery voltage response, a photovoltaic inverter at the end of a long secondary circuit, and 18 photovoltaic inverters on a distribution lateral. Default inverter settings are proposed for DER that would mitigate voltage fluctuations, with or without communications.

Automatic voltage control, distributed power gener↗

Distributed Automatic Generation Control Considering DPV Using T&D Dynamic Co-Simulation

The increasing adoption of distributed energy resources (DERs) over the last decade warrants a reconsideration of control of generation resources. This paper proposes a distributed Automatic Generation Control (AGC) using transmission-and-distribution (T&D) dynamic co-simulation framework for the efficient DPV frequency regulation services. The co-simulation framework allows AGC units to exchange the information for distributed AGC, based on their adopted communication network topology. As a result, a cost-effective automatic generation control is achieved with DPV and conventional generators. The proposed distributed AGC is based on the gossip algorithm in which the neighboring AGC units share the relevant local information with each other and updates their share of AGC regulation signal. Distributed photovoltaics (DPV) unit contribute to AGC response based on their headroom capacity via DER aggregators. The algorithm is tested on IEEE-14 bus transmission system under conditions of generation failure and random load variation to observe effective frequency regulations service offered by DPVs and other AGC units. The study shows that DPV can effectively participate in AGC with the proposed distributed control framework.

automatic generation control↗

DSS-SimPy-RL (Open-DSS and SimPy based Cyber-Physical RL environment) [SWR-23-29]

Recently, numerous data-driven approaches to control an electric grid using machine learning techniques have been investigated. With the advancement of reinforcement learning (RL) based techniques, gradually the conventional optimization based solvers are being replaced with RL approach where there is uncertainty in the environment such as renewable generation or cyber system emulation. However, to train an agent efficiently, it requires numerous interactions with an environment to learn the best policies. There are numerous RL environments for the power systems based on some well-known simulators, similarly there are environment for communication domains. While majority of the cyber emulators are based in an UNIX environment, the power simulators are based in the Windows-based operating system, the generation of cyber-physical mixed domain RL environment has been challenging. Existing co-simulation methods are efficient but resource and time intensive to generate large scale data set for training RL agents. Hence, this software focuses on development and validation of a mixed domain RL environment using Open DSS for the physical side and leverages a discrete event simulator python package, SimPy, for cyber-side emulation which is Operating Systems agnostic. Further utilizing this software co-simulation and training RL agents for re-routing based resilient control for network reconfiguration and volt-var control in power distribution feeder are performed.

Sahu, Abhijeet↗

Sizing an external-fueled in-core thermionic reactor.

Parametric studies on sizing of external-fueled in-core thermionic reactors are presented. Reactor physics results obtained for a variety of fuel element designs are used as a basis for nuclear criticality, power distribution, and control worth design. Thermionic performance results for a single fuel element for several sets of operating conditions are presented. An algorithm combining the electrical and reactor physics results in a form amenable to preliminary systems analysis is presented.

Nakashima, A. M.↗

Design analysis and computer-aided performance evaluation of shuttle orbiter electrical power system. Volume 1: Summary

Studies were conducted to develop appropriate space shuttle electrical power distribution and control (EPDC) subsystem simulation models and to apply the computer simulations to systems analysis of the EPDC. A previously developed software program (SYSTID) was adapted for this purpose. The following objectives were attained: (1) significant enhancement of the SYSTID time domain simulation software, (2) generation of functionally useful shuttle EPDC element models, and (3) illustrative simulation results in the analysis of EPDC performance, under the conditions of fault, current pulse injection due to lightning, and circuit protection sizing and reaction times.

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The HEAO-B Monitor Proportional Counter Instrument

The Monitor Proportional Counter Instrument for the HEAO-B X-ray Telescope satellite is designed to observe celestial X-ray sources in the range of 1 to 20 keV with intensities exceeding .0002 Crab. It provides both spectral and temporal data, to complement the data from the other HEAO-B instruments, to compare with observations from previous flights, as well as to allow detailed study of time variant X-ray phenomena. The basic detector is a large area proportional counter system, consisting of two counters, high voltage power supplies and preamplifiers, mounted behind a collimator with a 2/3 degree square field of view. The signal processing, power distribution and control electronics are contained in a separate unit, which includes circuitry to perform pulse height analysis, background rejection, time interval measurement, redundancy switching and control, housekeeping and telemetry interfacing.

Gaillardetz, R.↗

Satellite Power Systems (SPS) concept definition study. Volume 4: SPS point design definition

The satellite power systems point design concept is described. The concept definition includes satellite, ground and space systems, and their relationships. Emphasis is placed on the definition of the GaAlAs photovoltaic satellite system. The major subsystems of the satellite system including power conversion, power distribution and control, microwave, attitude control and stationkeeping, thermal control, structures, and information management and control are discussed.

Hanley, G.↗

Solar power satellite system definition study. Volume 3: Reference system description, phase 1

An analysis of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed including the structure, power distribution, thermal control, and energy storage. Space construction and support systems are described including the work support facilities and construction equipment. An assessment of the space transportation system for the satellite and the ground receiving station is presented.

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Payload carrier systems for conducting sortie mode science

The capabilities and characteristics of the payload carriers developed to provide structural and operational interfaces between the Space Shuttle and the various types of experiments designed to operate in the sortie mode are discussed. The Spacelab is a flexible laboratory system composed of interchangeable elements that can be put together in eight different combinations of pallets and pressurized modules, and provides considerable standard services to users in such areas as equipment installation, power distribution, thermal control, command and data management, software, pointing systems and crew participation. A modular three-axis pointing control system designated the Annular Suspension and Pointing System, is being developed to provide additional pointing capabilities to those payloads that require capabilities not provided by the Spacelab instrument pointing system. Two engineering models of the Spacelab pallet have been designated Orbital Flight Test Pallets which, together with a special experiment support structure, are intended for initial and operational payloads that do not constitute a complete Spacelab mission. The simplest and smallest payload carriers are the Getaway Special cans, intended for small, self-contained, self-sufficient payloads, and the orbiter middeck lockers. In this way, most of the user requirements for Shuttle sortie missions identified to date can be fulfilled.

Jean, O. C.↗

Marshall Amateur Club experiment (MARCE)

The integration of the Get Away Special (GAS) payload for the space shuttle is discussed in terms of systems design. In addition to the primary power, control, and distribution networks to electrically integrate the spaceborne experiments, an instrument measuring system, a data system, and a radio frequency downlink system were designed. A brief review of these systems is given.

Stluka, E. F.↗

Computer graphics applications to crew displays

Astronauts are provided much data and information via the monochrome CRT displays on the orbiter. For this project two areas were investigated for the possible introduction of computer graphics to enhance and extend the utility of these displays. One involved reviewing the current orbiter displays and identifying those which could be improved via computer graphics. As an example, the tabular data on electrical power distribution and control was enhanced by the addition of color and bar charts. The other dealt with the development of an aid to berthing a payload with the Remote Manipulator System (RMS). This aid consists of a graphics display of the top, front and side views of the payload and cargo bay and point of resolution (POR) position and attitude data for the current location of the payload. The initial implementation was on an IBM PC clone. The demonstration software installed in the Johnson Space Center Manipulator Development Facility (MD) was reviewed. Due to current hardware limitations, the MDF verision is slow, i.e., about a 40+ seond update rate and, hence, not real-time. Despite this fact, the evaluation of this additional visual cue as an RMS operator aid indicates that this display, with modifications for speed, etc., can assist the crew. Further development is appropriate.

Wyzkoski, J.↗

Independent Orbiter Assessment (IOA): Analysis of the orbital maneuvering system

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbital Maneuvering System (OMS) hardware are documented. The OMS provides the thrust to perform orbit insertion, orbit circularization, orbit transfer, rendezvous, and deorbit. The OMS is housed in two independent pods located one on each side of the tail and consists of the following subsystems: Helium Pressurization; Propellant Storage and Distribution; Orbital Maneuvering Engine; and Electrical Power Distribution and Control. The IOA analysis process utilized available OMS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluted and analyzed for possible failure modes and effects. Criticality was asigned based upon the severity of the effect for each failure mode.

Prust, C. D.↗

Independent Orbiter Assessment (IOA): Assessment of the EPD and C/remote manipulator system FMEA/CIL

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Electrical Power Distribution and Control (EPD and C)/Remote Manipulator System (RMS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA analysis of the EPD and C/RMS hardware initially generated 345 failure mode worksheets and identified 117 Potential Critical Items (PCIs) before starting the assessment process. These analysis results were compared to the proposed NASA Post 51-L baseline of 132 FMEAs and 66 CIL items.

Robinson, W. W.↗

Independent Orbiter Assessment (IOA): Assessment of the backup flight system FMEA/CIL

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Backup Flight System (BFS) hardware, generating draft failure modes and Potential Critical Items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed NASA Post 51-L FMEA/CIL baseline. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter BFS hardware. The IOA product for the BFS analysis consisted of 29 failure mode worksheets that resulted in 21 Potential Critical Items (PCI) being identified. This product was originally compared with the proposed NASA BFS baseline and subsequently compared with the applicable Data Processing System (DPS), Electrical Power Distribution and Control (EPD and C), and Displays and Controls NASA CIL items. The comparisons determined if there were any results which had been found by the IOA but were not in the NASA baseline. The original assessment determined there were numerous failure modes and potential critical items in the IOA analysis that were not contained in the NASA BFS baseline. Conversely, the NASA baseline contained three FMEAs (IMU, ADTA, and Air Data Probe) for CIL items that were not identified in the IOA product.

Prust, E. E.↗

Independent Orbiter Assessment (IOA): Assessment of the orbital maneuvering system FMEA/CIL, volume 1

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Orbital Maneuvering System (OMS) hardware and Electrical Power Distribution and Control (EPD and C), generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the proposed Post 51-L NASA FMEA/CIL baseline. This report documents the results of that comparison for the Orbiter OMS hardware. The IOA analysis defined the OMS as being comprised of the following subsystems: helium pressurization, propellant storage and distribution, Orbital Maneuvering Engine, and EPD and C. The IOA product for the OMS analysis consisted of 284 hardware and 667 EPD and C failure mode worksheets that resulted in 160 hardware and 216 EPD and C potential critical items (PCIs) being identified. A comparison was made of the IOA product to the NASA FMEA/CIL baseline which consisted of 101 hardware and 142 EPD and C CIL items.

Prust, Chet D.↗