222 research outputs found

    Microgravity fluid management in two-phase thermal systems

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    Initial studies have indicated that in comparison to an all liquid single phase system, a two-phase liquid/vapor thermal control system requires significantly lower pumping power, demonstrates more isothermal control characteristics, and allows greater operational flexibility in heat load placement. As a function of JSC's Work Package responsibility for thermal management of space station equipment external to the pressurized modules, prototype development programs were initiated on the Two-Phase Thermal Bus System (TBS) and the Space Erectable Radiator System (SERS). JSC currently has several programs underway to enhance the understanding of two-phase fluid flow characteristics. The objective of one of these programs (sponsored by the Microgravity Science and Applications Division at NASA-Headquarters) is to design, fabricate, and fly a two-phase flow regime mapping experiment in the Shuttle vehicle mid-deck. Another program, sponsored by OAST, involves the testing of a two-phase thermal transport loop aboard the KC-135 reduced gravity aircraft to identify system implications of pressure drop variation as a function of the flow quality and flow regime present in a representative thermal system

    A Forecasting-Based Control Algorithm for Improving Energy Management in High Concentrator Photovoltaic Power Plant Integrated with Energy Storage Systems

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    The High Concentrator Photovoltaic (HCPV) technology, due to its high efficiency, is considered one of the most promising solutions for the exploitation of sun-irradiation-based Renewable Energy Sources (RES). Nevertheless, the HCPV production is strictly connected to the Direct Normal Irradiation (DNI) making this photovoltaic technology more sensible to cloudiness than traditional ones. In order to mitigate the power intermittence and improve production programmability, the integration between Energy Storage Systems (ESSs) and HCPV, resorting to forecasting algorithms, has been investigated. Specifically, a local weather forecasting algorithm has been used for estimating the daily time evolution of DNI, air Temperature (T), Wind Speed (WS), and Air Mass (AM). These data are subsequently processed by means of an accurate HCPV model for the estimation of one day-ahead daily power production profile. The processing of HCPV forecasted generation by means of a properly tuned filter-based algorithm allows one day-ahead the definition of power profiles of ESS and power plant respectively, considering also the ESS constraints and the characteristic of the implemented real-time control algorithm. The effectiveness of the proposed forecasting model and control algorithm is verified through a simulation study referring to the solar power plant constituted by HCPV and ESS installed in Ottana, Italy. The results highlight that the application of the proposed approach lessens the power fluctuation effect caused by HCPV generation preserving the batteries at the same time. The feasibility and advantages of the proposed approach are finally presented

    Energy management system of hybrid microgrid with energy storage

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    The economic scheduling of the generation units is playing a significant role in the energy management of the hybrid stand alone microgrid. Energy storage is an increasingly important part of the renewable energy sector because of the need to store power during peak production times for use in off-peak periods. This paper describes an energy management system (EMS) for an islanded microgrid (MG) comprising wind energy conversion system (WECS),photovoltaic (PV), energy storage (ES) system, and microturbine (MT) for calculating the battery charging price (BCP) factor. To reach this objective, firstly the battery system has been modeled using the presented equations then various scenarios is applied by technically limited such as the power, voltage and current applied to charge and discharge of the battery.Postprint (published version

    Green radios systems

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    Essential overview of GRS implementation scenarios. The needs of GRS and some concrete cases exampleope
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