Search results for "Losses"

Driven Primary Regulation for Minimum Power Losses Operation in Islanded Microgrids

2018

The paper proposes an improved primary regulation method for inverter-interfaced generating units in islanded microgrids. The considered approach employs an off-line minimum losses optimal power flow (OPF) to devise the primary frequency regulation curve’s set-points while satisfying the power balance, frequency and current constraints. In this way, generators will reach an optimized operating point corresponding to a given and unique power flow distribution presenting the minimum power losses. The proposed approach can be particularly interesting for diesel-based islanded microgrids that face, constantly, the issue of reducing their dependency from fossil fuels and of enhancing their gener…

Uncertainty evaluation in the differential measurements of power losses in a power drive system

2021

Abstract In order to guarantee a correct classification in the standardized energy efficiency classes, the current standards concerning the power drive systems prescribe that their power losses must be evaluated with great accuracy. This circumstance involves the usage of expensive measurement systems, since accurate instrumentation, skilled personnel and controlled environments are required. During the design stage of a power drive system, however, the measurement of the absolute value of its power losses is not always needed. Often, in fact, it is enough to assess the power losses variations caused by a modification of either hardware or software sections of the power drive system. In the…

Las crecidas en ramblas valencianas mediterráneas

2001

This paper takes into account the characterisation of ephemeral stream hydrology from Mediterranean environments. The heavy floods that these countries suffer are due to firstly, the physical watershed features (steep slopes, scarced vegetation cover and thin soils) and, secondly, to the intense and variable rainfall. Large quantities of precipitation fall in a matter of hours, or even minutes, over very steep catchments, causing catastrophic flash-floods, with very pointed hydrographs and short time lags. Using hydrological daily data from the Rambla de la Viuda basin and five-minute data from both Barranc de Carraixet and Rambla de Poyo basins, we have analysed the rainfall- runoff proces…

ICT applications for improving the generation and distribution efficiency of a small mediterranean island

2016

The paper presents a study on the opportunities offered by ICT for improving the efficiency of the generation and distribution system of a small island. The island taken into consideration is the Italian Lampedusa island. In the paper, the power distribution system of the island is described and the summer and winter daily load profiles are examined in order to define the more suitable control actions for improving the generation and distribution efficiency of the power system. Finally the architecture of an idoneous control system for the smart grid is proposed and an evaluation of the purchase and installation costs of components and devices for the transition of a traditional house towar…

Assessing a computational fluid dynamic technique (CFD) to evaluate pressure losses in drip irrigation laterals

2005

Designing Trickle Irrigation Systems in Sloping Fields without Pressure-Compensating Emitters: Application of the IRRILAB Software

2022

When designing trickle irrigation systems in sloped fields, the use of pressure-compensating (PC) emitters is generally preferred to ensure the emitter distribution uniformity regardless of the land topography and the variable operating pressures. However, the cost of PC emitters is generally higher than non-pressure-compensating (NPC) ones; moreover, the compensating membrane installed inside the emitters can lose elasticity due to the exposition to solar radiation, water quality, and chemical applications. Recently, the irrigation laboratory (IRRILAB) version 1.0 software application was developed to design microirrigation systems for rectangular and planar sectors when using NPC emitters…

Contagious agalactiae: a preliminary study on its impact on milk production of Sicilian sheep

2014

Room-temperature performance of 3 mm-thick cadmium-zinc-telluride pixel detectors with sub-millimetre pixelization.

2020

Cadmium–zinc–telluride (CZT) pixel detectors represent a consolidated choice for the development of room-temperature spectroscopic X-ray imagers, finding important applications in medical imaging, often as detection modules of a variety of new SPECT and CT systems. Detectors with 3–5 mm thicknesses are able to efficiently detect X-rays up to 140 keV giving reasonable room-temperature energy resolution. In this work, the room-temperature performance of 3 mm-thick CZT pixel detectors, recently developed at IMEM/CNR of Parma (Italy), is presented. Sub-millimetre detector arrays with pixel pitch less than 500 µm were fabricated. The detectors are characterized by good room-temperature performan…

Room-Temperature X-ray response of cadmium-zinc-Telluride pixel detectors grown by the vertical Bridgman technique

2020

In this work, the spectroscopic performances of new cadmium–zinc–telluride (CZT) pixel detectors recently developed at IMEM-CNR of Parma (Italy) are presented. Sub-millimetre arrays with pixel pitch less than 500 µm, based on boron oxide encapsulated vertical Bridgman grown CZT crystals, were fabricated. Excellent room-temperature performance characterizes the detectors even at high-bias-voltage operation (9000 V cm−1), with energy resolutions (FWHM) of 4% (0.9 keV), 1.7% (1 keV) and 1.3% (1.6 keV) at 22.1, 59.5 and 122.1 keV, respectively. Charge-sharing investigations were performed with both uncollimated and collimated synchrotron X-ray beams with particular attention to the mitigation o…

Influence of the manufacturing process on the radiation sensitivity of fluorine-doped silica-based optical fibers

2011

International audience; In this work, we analyze the origins of the observed differences between the radiation sensitivities of fluorine-doped optical fibers made with different fabrication processes. We used several experimental techniques, coupling in situ radiation-induced absorption measurements with post mortem confocal microscopy luminescence measurements. Our data showed that the silica intrinsic defects are generated both from precursor sites and from strained regular Si-O-Si linkages. Our work also provides evidence for the preponderant role of the chlorine in determining the optical losses at about 3.5 eV. The results show that the manufacturing process of these fibers strongly af…