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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Numerical Propulsion System Simulation (NPSS) Power Systems Library

This presentation covers the Numerical Propulsion System Simulation (NPSS) Power Systems Library being developed by NASA. This library is a set of components, models, and interfaces for the NPSS language to enable building electric power system models for electrified propulsion systems. The presentation is to be given at the 3rd annual RVLT Toolchain Workshop, where attendees from across the eVTOL industry will be informed of NASA’s tools for eVTOL conceptual design from the vehicle level down through subsystems including propulsion, noise, electrical power, and others. It covers where the NPSS Power System Library fits into NASA’s RVLT toolchain and RVLT work in general, and will inform the audience of how the tool can be useful in their own work.

Electric vertical takeoff and landing↗
NASA NTRS1987

Hubble Space Telescope electrical power system simulation breadboard

The components and operation of the Hubble Space Telescope (HST) electrical power system (EPS) breadboard are described. The HST EPS breadboard consists of: (1) the power distribution breadboard, (2) the batteries, (3) the solar array simulators, (4) the load banks, (5) the charge current control hardware, and (6) a control computer; the functions of each of these elements are discussed. The HST EPS has been used to simulate changes in charge level, charge control schemes, and beta angle, failed cells, batteries, solar panel assemblies (SPAs), beginning of life SPAs, and end of life SPAs, and temperature differences. The test data reveal that the HST EPS is capable of operating over a wide range of conditions.

Bush, John R., Jr.↗
NASA NTRS1984

Electric-Power System Simulator

Shows different combinations of generation, storage, and load components: display, video monitor with keyboard input to microprocessor, and video monitor for display of load curves and power generation. Planning tool for electric utilities, regulatory agencies, and laymen in understanding basics of electric-power systems operation.

Caldwell, R. W.↗
NASA NTRS2010

Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, Ohio. This is a closed-cycle system that incorporates an electrically heated reactor core module, turboalternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

Bragg-Sitton, Shannon M.↗
NASA NTRS2009

Testing of an Integrated Reactor Core Simulator and Power Conversion System with Simulated Reactivity Feedback

A Direct Drive Gas-Cooled (DDG) reactor core simulator has been coupled to a Brayton Power Conversion Unit (BPCU) for integrated system testing at NASA Glenn Research Center (GRC) in Cleveland, OH. This is a closed-cycle system that incorporates an electrically heated reactor core module, turbo alternator, recuperator, and gas cooler. Nuclear fuel elements in the gas-cooled reactor design are replaced with electric resistance heaters to simulate the heat from nuclear fuel in the corresponding fast spectrum nuclear reactor. The thermodynamic transient behavior of the integrated system was the focus of this test series. In order to better mimic the integrated response of the nuclear-fueled system, a simulated reactivity feedback control loop was implemented. Core power was controlled by a point kinetics model in which the reactivity feedback was based on core temperature measurements; the neutron generation time and the temperature feedback coefficient are provided as model inputs. These dynamic system response tests demonstrate the overall capability of a non-nuclear test facility in assessing system integration issues and characterizing integrated system response times and response characteristics.

Bragg-Sitton, Shannon M.↗
NASA NTRS1978

Mathematical simulation of power conditioning systems. Volume 1: Simulation of elementary units. Report on simulation methodology

Methods and algorithms used for the simulation of elementary power conditioning units buck, boost, and buck-boost, as well as shunt PWM are described. Definitions are given of similar converters and reduced parameters. The various parts of the simulation to be carried out are dealt with; local stability, corrective network, measurements of input-output impedance and global stability. A simulation example is given.

Prajous, R.↗
NASA NTRS1987

Modeling and simulation of spacecraft power systems

EASY5 modeling of a complete spacecraft power processing system is presented. Component models are developed, and several system models including a solar array switching system, a partially-shunted solar array system and COBE system are simulated. The power system's modes of operation, such as shunt mode, battery-charge mode, and battery-discharge mode, are simulated for a complete orbit cycle.

Lee, J. R.↗
NASA NTRS1976

EDIN0613P weight estimating program

The weight estimating relationships and program developed for space power system simulation are described. The program was developed to size a two-stage launch vehicle for the space power system. The program is actually part of an overall simulation technique called EDIN (Engineering Design and Integration) system. The program sizes the overall vehicle, generates major component weights and derives a large amount of overall vehicle geometry. The program is written in FORTRAN V and is designed for use on the Univac Exec 8 (1110). By utilizing the flexibility of this program while remaining cognizant of the limits imposed upon output depth and accuracy by utilization of generalized input, this program concept can be a useful tool for estimating purposes at the conceptual design stage of a launch vehicle.

Hirsch, G. N.↗
NASA NTRS1973

Isotope heat source simulator for testing of space power systems

A reliable isotope heat source simulator was designed for use in a Brayton power system. This simulator is composed of an electrically heated tungsten wire which is wound around a boron nitride core and enclosed in a graphite jacket. Simulator testing was performed at the expected operating temperature of the Brayton power system. Endurance testing for 5012 hours was followed by cycling the simulator temperature. The integrity of this simulator was maintained throughout testing. Alumina beads served as a diffusion barrier to prevent interaction between the tungsten heater and boron nitride core. The simulator was designed to maintain a surface temperature of 1311 to 1366 K (1900 to 2000 F) with a power input of approximately 400 watts. The design concept and the materials used in the simulator make possible man different geometries. This flexibility increases its potential use.

Prok, G. M.↗
NASA NTRS1987

Simulation of dc spacecraft power systems using state variable techniques

The modeling and simulation of large dc spacecraft power systems necessitates considering the spacecraft power system as an interconnection of modular components. This paper presents a state-variable-based approach for dc spacecraft power system modeling and simulation. Each modular component is treated as a two-port network, and a state model is written with the port voltages as the inputs. The state model of a component is solved independently of the other components using its state transition matrix. The state variables of each component are updated assuming that the inputs are constant. Network analysis principles are then utilized to calculate the component inputs.

Nelms, R. M.↗
NASA NTRS2014

The Use of Software Agents for Autonomous Control of a DC Space Power System

In order to enable manned deep-space missions, the spacecraft must be controlled autonomously using on-board algorithms. A control architecture is proposed to enable this autonomous operation for an spacecraft electric power system and then implemented using a highly distributed network of software agents. These agents collaborate and compete with each other in order to implement each of the control functions. A subset of this control architecture is tested against a steadystate power system simulation and found to be able to solve a constrained optimization problem with competing objectives using only local information.

autonomous control↗
NASA NTRS1988

A simulation model for reliability evaluation of Space Station power systems

A detailed simulation model for the hybrid Space Station power system is presented which allows photovoltaic and solar dynamic power sources to be mixed in varying proportions. The model considers the dependence of reliability and storage characteristics during the sun and eclipse periods, and makes it possible to model the charging and discharging of the energy storage modules in a relatively accurate manner on a continuous basis.

Singh, C.↗
NASA NTRS2021

Power Autonomy Research and Development Environment (PARDE) User’s Guide Version 0.1.2

This document is a user's guide for the Power Autonomy Research and Development Environment (PARDE) software package. PARDE is a version of NASA's Autonomous Power Control (APC) software that can be used to evaluate fault management and automatic power system reconfiguration algorithms in a relevant system without having to fully develop all the supporting software. Software items included are a set of C++ class source files representing simplified fault management and reconfiguration logic, a power system simulation representing a notional architecture for NASA's Gateway vehicle, a web-based graphical user interface for running and testing the simulation and APC, a Docker-based automatic setup script for a development environment, and a user's guide.

autonomous power control↗
NASA NTRS1986

Computer-Aided Modeling and Analysis of Power Processing Systems (CAMAPPS). Phase 1: Users handbook

The EASY5 macro component models developed for the spacecraft power system simulation are described. A brief explanation about how to use the macro components with the EASY5 Standard Components to build a specific system is given through an example. The macro components are ordered according to the following functional group: converter power stage models, compensator models, current-feedback models, constant frequency control models, load models, solar array models, and shunt regulator models. Major equations, a circuit model, and a program listing are provided for each macro component.

Kim, S.↗
NASA NTRSDate not supplied

Multi-Convertor Configurable Simulator for Dynamic Radioisotope Power Systems

This paper presents the multi-convertor configurable simulator (MCCS) that can emulate piston/displacer dynamics and power outputs of various types of free-piston Stirling convertors developed at NASA GRC, including Technical Demonstration Convertor (TDC), Advanced Stirling Convertor (ASC), Flexure Isotope Stirling Convertor (FISC), Sunpower Robust Stirling Convertor (SRSC), and P2A. The MCCS can emulate up to four convertors, instead of two convertors in state-of-the-art Stirling simulators, and the maximum power output for each convertor is 1kW. Furthermore, hardware and software changes required to switch between convertors are minimized for easy conversion. A hardware-in-loop (HIL) system is used to easily switch between convertors by updating linearized modeling parameters in software. Also, switched-mode AC power supplies are used to generate wide ranges of voltage and current to emulate different types of Stirling convertors without replacing AC power supplies. Finally, the inductors emulating the linear alternator, which is the only hardware change needed for conversion, are modularized in alternator boxes to enable easy replacement of the inductors. These two features—easy conversion and capability of emulating up to four 1kW-convertors—will enable the validation tests of multi-convertor controller (MCC) concepts that are being developed by APL, the Dynamic Radioisotope Power System (DRPS) generator, and other controller developments for current and future DRPS flight projects. Finally, the MCCS is configured to demonstrate emulation of four FISCs and the outputs of the MCCS are compared with experimental data from the actual FISC.

Free-Piston Stirling Convertor Controller↗
NASA NTRS1983

Space environmental effects on materials

Research efforts at NASA-Langley to characterize the durability of composite materials which are candidates or use as components on various space hardware systems are reviewed. The material applications include large space structures, antennas, cables, thermal control coatings, solar reflectors, and satellite power systems. Simulation facilities have been built to study radiation effects on polymer matrix composites, and the dimensional stability of the matrix composites and tension stabilized.

Tenny, D. R.↗