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At least 991 records · Page 55

Energy Equity: From Sociological Concept to Engineering Perspective of Electric Power Systems

The implementation of energy equity has emerged as a pivotal goal of the global energy transition, driven by widespread recognition of energy inequities worldwide. Because energy equity is broadly regarded as a sociological concept rather than an engineering one, the current absence of technical engineering methods necessitates the development of a justified and sound approach to making energy equity an actionable practice in the broader realms of energy, environment, and sustainability. This Perspective discusses different terms related to energy equity and proposes a generalized definition of energy equity from the engineering perspective of electric power systems. To address these challenges related to energy equity, policies in Europe and the U.S. are introduced, although their effectiveness is limited. Further, current energy equity research is classified into four categories: quantifying energy equity, improving equity in the accessibility of electricity, improving equity in the affordability of electricity, and improving equity in the resilience of power systems. Then, we classify the ongoing research challenges in energy equity into two categories, technical challenges and application challenges, and provide corresponding insights. Finally, we discuss equity of resilience or reliability, income disparity, and environmental equity, followed by a summary of this Perspective.

29 ENERGY PLANNING, POLICY, AND ECONOMY

Computer program for thermodynamic analysis of open cycle multishaft power system with multiple reheat and intercool

A computer program to analyze power systems having any number of shafts up to a maximum of five is presented. On each shaft there can be as many as five compressors and five turbines, along with any specified number of intervening intercoolers and reheaters. A recuperator can be included. Turbine coolant flow can be accounted for. Any fuel consisting entirely of hydrogen and/or carbon can be used. The program is valid for maximum temperatures up to about 2000 K (3600 R). The system description, the analysis method, a detailed explanation of program input and output including an illustrative example, a dictionary of program variables, and the program listing are explained.

Glassman, A. J.

Satellite Power System (SPS) military implications

The military implications of the reference satellite power system (SPS) were examined is well as important military related study tasks. Primary areas of investigation were the potential of the SPS as a weapon, for supporting U.S. military preparedness, and for affecting international relations. In addition, the SPS's relative vulnerability to overt military action, terrorist attacks, and sabotage was considered.

Bain, C. N.

NASCAP modelling of high-voltage power system interactions with space charged-particle environments

A simple space power system operating in geosynchronous orbit was analyzed. This system consisted of two solar array wings and a central body. Each solar array wing was considered to be divided into three regions operating at 2000 volts. The center body was considered to be an electrical ground with the array voltages both positive and negative relative to ground. The system was analyzed for both a normal environment and a moderate geomagnetic substorm environment. Initial results indicate a high probability of arcing at the interconnects on the negative operating voltage wing. The dielectric strength of the substrate may be exceeded giving rise to breakdown in the bulk of the material. The geomagnetic substorm did not seem to increase the electrical gradients at the interconnects on the negative operating voltage wing but did increase the gradients on the positive operating voltage wing which could result in increased coupling current losses.

Stevens, N. J.

Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 4: Commercial System Definition

The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. The operational reliability, the minimum risk of failure, and the maintenance and repair characteristics are determined and the commercial system design is defined.

Holl, R. J.

Spaceborne power systems preference analyses. Volume 2: Decision analysis

Sixteen alternative spaceborne nuclear power system concepts were ranked using multiattribute decision analysis. The purpose of the ranking was to identify promising concepts for further technology development and the issues associated with such development. Four groups were interviewed to obtain preference. The four groups were: safety, systems definition and design, technology assessment, and mission analysis. The highest ranked systems were the heat-pipe thermoelectric systems, heat-pipe Stirling, in-core thermionic, and liquid-metal thermoelectric systems. The next group contained the liquid-metal Stirling, heat-pipe Alkali Metal Thermoelectric Converter (AMTEC), heat-pipe Brayton, liquid-metal out-of-core thermionic, and heat-pipe Rankine systems. The least preferred systems were the liquid-metal AMTEC, heat-pipe thermophotovoltaic, liquid-metal Brayton and Rankine, and gas-cooled Brayton. The three nonheat-pipe technologies selected matched the top three nonheat-pipe systems ranked by this study.

Smith, J. H.

Parametric analysis of a thermionic space nuclear power system

Key parameters in the design of a thermionic space nuclear power system are identified and analysed in various system tradeoffs. The results are referenced to the thermionic system currently being studied for the SP-100 program. The SP-100 requirements provide definitive guidelines with respect to system optimization, the primary ones being the system mass limit of 3000 kg, the system volume constrraint of one-third of the Space Shuttle cargo bay, and the system lifetime of seven years. Many parametric influences are described and the methods used to optimize system design, in the context of the requirements, are indicated. Considerable design flexiblity is demonstrated.

Strohmayer, W. H.

Solar simulator for solar dynamic space power system testing

Planned vacuum tank testing of a solar dynamic space power system requires a solar simulator. Several solar simulators were previously built and used for vacuum tank testing of various space systems. However, the apparent solar subtense angle, i.e., the angular size of the apparent sun as viewed from the experiment, of these solar simulators is too large to enable testing of solar dynamic systems. A new design was developed to satisfy the requirements of the solar dynamic testing. This design provides 1.8 kW/m(sup 2) onto a 4.5M diameter test area from a source that subtends only 1 deg, full cone angle. Key features that enable this improved performance are (1) elimination of the collimating mirror commonly used in solar simulators to transform the diverging beam into a parallel beam; (2) a redesigned lamp module that has increased efficiency; and (3) the use of a segmented reflective surface to combine beams from several individual lamp modules at the pseudosun. Each segment of this reflective surface has complex curvature to control the distribution of light. By developing a new solar simulator design for testing of the solar dynamic system instead of modifying current designs, the initial cost was cut in half, the efficiency was increased by 50 percent reducing the operating costs by one-third, and the volume occupied by the solar simulator was reduced by a factor of 10.

Jefferies, Kent S.

Methods for Probabilistic Fault Diagnosis: An Electrical Power System Case Study

Health management systems that more accurately and quickly diagnose faults that may occur in different technical systems on-board a vehicle will play a key role in the success of future NASA missions. We discuss in this paper the diagnosis of abrupt continuous (or parametric) faults within the context of probabilistic graphical models, more specifically Bayesian networks that are compiled to arithmetic circuits. This paper extends our previous research, within the same probabilistic setting, on diagnosis of abrupt discrete faults. Our approach and diagnostic algorithm ProDiagnose are domain-independent; however we use an electrical power system testbed called ADAPT as a case study. In one set of ADAPT experiments, performed as part of the 2009 Diagnostic Challenge, our system turned out to have the best performance among all competitors. In a second set of experiments, we show how we have recently further significantly improved the performance of the probabilistic model of ADAPT. While these experiments are obtained for an electrical power system testbed, we believe they can easily be transitioned to real-world systems, thus promising to increase the success of future NASA missions.

Ricks, Brian W.

NASA's Radioisotope Power Systems Program Overview - A Focus on RPS Users

The goal of NASA's Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet potential future mission needs. To meet this goal, the RPS Program manages investments in RPS technologies and RPS system development, working closely with the Department of Energy. This paper provides an overview of the RPS Program content and status, its collaborations with potential RPS users, and the approach employed to maintain the readiness of RPS to support future NASA mission concepts.

Radioisotope

Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 1: Executive Summary

The development of a modular solar thermal power system for application in the 1 to 10 MWe range is presented. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. Investigations are performed on the energy storage requirements and type of energy storage, concentrator design and field optimization, energy transport, and power conversion subsystems. The system utilizes a Rankine cycle, an axial flow steam turbine for power conversion, and heat transfer sodium for collector fluid.

Holl, R. J.

Liquid Metals for Aerospace Electric-Power Systems

Liquid metals and their properties, as applied to space electric-power systems, are discussed as possible heat-transfer and thermodynamic working fluids. Representative liquid metals—lithium, sodium, potassium, NaK-78, lead, and bismuth — tare discussed and compared. Space power requirements are listed and used as a basis for evaluating the potentialities of the liquid metals.

Heat transfer