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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 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Controller Hardware-in-the-Loop Evaluation of a Microgrid Controller for a Microgrid System with Multiple Grid-Forming Inverters: Preprint

This paper presents the laboratory evaluation of a commercial Microgrid Management System (MGMS) implemented in the real-world Bronzeville Microgrid which features a futuristic scenario with high renewable energy integration and the use of multiple Grid-Forming (GFM) inverters. The primary objective of the performance evaluation for the MGMS is to assess the MGMS's capability to dispatch GFM units, including a GFM PV unit and two GFM battery units, to maintain the system stability and ensure economic operation, thus guaranteeing the microgrid's resilience during prolonged outages and dynamic events. The laboratory controller hardware-in-the-loop provides realistic testing environment through detailed electromagnetic transient modeling of the microgrid system, hardware MGMS, and standard communication protocols (DNP3). The CHIL evaluation shows how the MGMS effectively manages the GFM inverters, highlighting its performance in maintaining stability, reliability, and survivability in a microgrid environment with a high penetration of renewable energy sources.

controller hardware-in-the-loop↗
DOE OSTI2024

Controller-Hardware-in-the-Loop Evaluation of a Microgrid Controller for a Microgrid System With Multiple Grid-Forming Inverters

This paper presents the laboratory evaluation of a commercial Microgrid Management System (MGMS) implemented in the real-world Bronzeville Microgrid which features a futuristic scenario with high renewable energy integration and the use of multiple Grid-Forming (GFM) inverters. The primary objective of the performance evaluation for the MGMS is to assess the MGMS's capability to dispatch GFM units, including a GFM PV unit and two GFM battery units, to maintain the system stability and ensure economic operation, thus guaranteeing the microgrid's resilience during prolonged outages and dynamic events. The laboratory controller hardware-in-the-loop provides realistic testing environment through detailed electromagnetic transient modeling of the microgrid system, hardware MGMS, and standard communication protocols (DNP3). This CHIL evaluation shows how the MGMS effectively manages the GFM inverters, highlighting its performance in maintaining stability, reliability, and survivability in a microgrid environment with a high penetration of renewable energy sources.

controller hardware-in-the-loop↗
DOE OSTI2019

Structure‐based control of the rate limitation of photosynthetic electron transport

The 2.5 Å structure of the cytochrome (cyt) b 6 f complex provides a basis for control of the rate‐limiting electron transfer step of oxygenic photosynthesis associated with the plastoquinol/quinone exchange pathway. Here, a structural change was made at a site containing two proline residues which border the intra‐cyt pathway for plastoquinol/quinone exchange. The proline side chains confer a larger aperture for passage of plastoquinol/quinone. Change of these prolines to alanine in the cyanobacterium Synechococcus sp. PCC 7002 results in attenuation of this rate‐limiting step, observed by a two‐fold reduction in the rate of cell growth, O 2 evolution, and plastoquinol‐mediated reduction of cyt f . This study demonstrates modification by site‐directed mutagenesis of photosynthetic energy transduction based on rational application of information in the atomic structure.

Ness, Jillian↗
DOE OSTI2019

Shape-Controlled CO 2 Electrochemical Reduction on Nanosized Pd Hydride Cubes and Octahedra

Electrochemical CO 2 reduction reaction (CO 2 RR) provides a potential pathway to mitigate challenges related to CO 2 emissions. Pd nanoparticles have shown interesting properties as CO 2 RR electrocatalysts, while how different facets of Pd affect its performance in CO 2 reduction to synthesis gas with controlled H 2 to CO ratios has not been studied. Herein, we synthesized nano-sized Pd cubes and octahedra particles dominated by Pd(100) and Pd(111) facets, respectively. Here, the Pd octahedra particles show higher CO selectivity (up to 95%) and better activity than Pd cubes and commercial particles. For both Pd octahedra and cubes, the ratio of H 2 /CO products was tunable between 1 and 2, a desirable ratio for methanol production and the Fischer-Tropsch processes. Further studies of Pd octahedra in a 25-cm 2 flow cell showed a total CO current of 5.47 A was achieved at a potential of 3.4 V, corresponding to a CO partial current density of 220 mA/cm -2 . In situ X-ray absorption spectroscopy studies showed that regardless of facet Pd transformed into Pd hydride (PdH) under reaction conditions. DFT calculations show that the reduced binding energies of CO and HOCO intermediates on PdH(111) are key parameters to the high current density and Faradaic efficiency in CO 2 to CO conversion.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Multielectrode Array Sensors to Enable Long-Duration Corrosion Monitoring and Control of Concentrating Solar Power Systems

Molten mixtures of MgCl2-KCl-NaCl are promising heat transfer fluid (HTF) candidates for the next generation of concentrating solar power systems (Gen3 CSP), because of their low cost, high decomposition temperature, and favorable heat transfer characteristics. However, if the chemistry of the salts is not properly controlled, molten chlorides can cause corrosion of high-temperature metal alloys, such as Inconel (R), in CSP systems. Here we demonstrate a corrosion monitoring system that can be used to monitor the health of the structural alloys over long durations. The monitoring system includes a multielectrode array voltammetry sensor that measures the redox potential of molten MgCl2-KCl-NaCl mixture as well as the presence of corrosion products and impurities. The sensors have been successfully operated in static molten salt environments for long durations, and are capable of detecting corrosion products, such as Cr2+ and Fe2+, quantitatively at low concentrations (i.e., approximately 100 ppm) with less than 4% error.

Concentrated solar power↗