Sara Sulis is Associate Professor of Electrical and Electronic Measurements at the Department of Electrical and Electronic Engineering of the University of Cagliari
Power systems are rapidly evolving, and correspondingly control and management systems require mo... more Power systems are rapidly evolving, and correspondingly control and management systems require more reliable and accurate information on the operating conditions of the grids, in order to manage them. This information can be acquired in several ways and can concern different types of data. The possibility of obtaining such information and its relevance is particularly connected to the smart grids (SGs) scenario, for which the knowledge of operating conditions is critical for secure and reliable supply and for full exploitation of the energy resources.
DarkSide uses a dual-phase Liquid Argon Time Projection Chamber (TPC) to search for WIMP dark mat... more DarkSide uses a dual-phase Liquid Argon Time Projection Chamber (TPC) to search for WIMP dark matter. The paper will present the latest result on the search for low mass ($M_{WIMP} 100\,Gev/c^2$) WIMPs from the current experiment, DarkSide-50, running since mid 2015 a 50-kg-active-mass TPC, filled with argon from an underground source. The next stage of the DarkSide program will be a new generation experiment involving a global collaboration from all the current Argon based experiments. DarkSide-20k, is designed as a 20-tonne fiducial mass TPC with SiPM based photosensors, expected to be free of any background for an exposure of >100 ton x years. Like its predecessor DarkSide-20k will be housed at the Gran Sasso (LNGS) underground laboratory, and it is expected to attain a WIMP-nucleon cross section exclusion sensitivity of $10^{-47}\,cm^2$ for a WIMP mass of $1\,TeV/c^2$ in a 5 yr run. A subsequent objective, towards the end of the next decade, will be the construction of the ul...
2021 IEEE 11th International Workshop on Applied Measurements for Power Systems (AMPS), 2021
Accurate monitoring tools are fundamental for the proper operation of the transmission grids. In ... more Accurate monitoring tools are fundamental for the proper operation of the transmission grids. In this context, an essential requirement for the transmission system operator is the availability of accurate knowledge on transmission line and transformer characteristics. Despite the high accuracy of the increasingly used Phasor Measurements Units (PMUs), there are still significant issues associated with the knowledge of the actual line parameters and on the actual tap changer ratio. In this regard, the paper proposes a method to estimate simultaneously the line parameters, the tap changer ratio, and the systematic measurement errors associated with the instrument transformers. With an appropriate model of the measurement chain, which includes the uncertainties associated with instrument transformers and PMUs, a linear formulation of the line and transformer constraint equations can be applied and accurate results can be obtained. The validity of the proposed method is confirmed by different types of tests performed on the IEEE 14-bus test system.
Journal of Cosmology and Astroparticle Physics, 2021
Future liquid-argon DarkSide-20k and Argo detectors, designed for direct dark matter search, will... more Future liquid-argon DarkSide-20k and Argo detectors, designed for direct dark matter search, will be sensitive also to core-collapse supernova neutrinos, via coherent elastic neutrino-nucleus scattering. This interaction channel is flavor-insensitive with a high-cross section, enabling for a high-statistics neutrino detection with target masses of ∼50 t and ∼360 t for DarkSide-20k and Argo respectively. Thanks to the low-energy threshold of ∼0.5 keVnr achievable by exploiting the ionization channel, DarkSide-20k and Argo have the potential to discover supernova bursts throughout our galaxy and up to the Small Magellanic Cloud, respectively, assuming a 11-M☉ progenitor star. We report also on the sensitivity to the neutronization burst, whose electron neutrino flux is suppressed by oscillations when detected via charged current and elastic scattering. Finally, the accuracies in the reconstruction of the average and total neutrino energy in the different phases of the supernova burst,...
Aria is a plant hosting a$${350}\,\hbox {m}$$350mcryogenic isotopic distillation column, the tall... more Aria is a plant hosting a$${350}\,\hbox {m}$$350mcryogenic isotopic distillation column, the tallest ever built, which is being installed in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. It was designed to reduce the isotopic abundance of$${^{39}\hbox {Ar}}$$39Arin argon extracted from underground sources, called Underground Argon (UAr), which is used for dark-matter searches. Indeed,$${^{39}\hbox {Ar}}$$39Aris a$$\beta $$β-emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors. In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of the isotopic cryogenic distillation of nitrogen with a prototype plant.
Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area ... more Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area monitoring system (WAMS), were historically conceived for transmission networks. The current trend to extend the benefits of the synchrophasor technology to distribution networks requires the PMU to also provide trustworthy information in the presence of signals that can occur in a typical distribution grid, including the presence of severe power quality (PQ) issues. In this framework, this paper experimentally investigates the performance of PMUs in the presence of one of the most important PQ phenomena, namely the presence of voltage fluctuations that generate the disturbance commonly known as flicker. The experimental tests are based on an ad-hoc high-accuracy measurement setup, where the devices under test are considered as “black boxes” to be characterized in the presence of the relevant signals. Two simple indices are introduced for the comparison among the different tested PMUs. T...
Power systems are rapidly evolving, and correspondingly control and management systems require mo... more Power systems are rapidly evolving, and correspondingly control and management systems require more reliable and accurate information on the operating conditions of the grids, in order to manage them. This information can be acquired in several ways and can concern different types of data. The possibility of obtaining such information and its relevance is particularly connected to the smart grids (SGs) scenario, for which the knowledge of operating conditions is critical for secure and reliable supply and for full exploitation of the energy resources.
DarkSide uses a dual-phase Liquid Argon Time Projection Chamber (TPC) to search for WIMP dark mat... more DarkSide uses a dual-phase Liquid Argon Time Projection Chamber (TPC) to search for WIMP dark matter. The paper will present the latest result on the search for low mass ($M_{WIMP} 100\,Gev/c^2$) WIMPs from the current experiment, DarkSide-50, running since mid 2015 a 50-kg-active-mass TPC, filled with argon from an underground source. The next stage of the DarkSide program will be a new generation experiment involving a global collaboration from all the current Argon based experiments. DarkSide-20k, is designed as a 20-tonne fiducial mass TPC with SiPM based photosensors, expected to be free of any background for an exposure of >100 ton x years. Like its predecessor DarkSide-20k will be housed at the Gran Sasso (LNGS) underground laboratory, and it is expected to attain a WIMP-nucleon cross section exclusion sensitivity of $10^{-47}\,cm^2$ for a WIMP mass of $1\,TeV/c^2$ in a 5 yr run. A subsequent objective, towards the end of the next decade, will be the construction of the ul...
2021 IEEE 11th International Workshop on Applied Measurements for Power Systems (AMPS), 2021
Accurate monitoring tools are fundamental for the proper operation of the transmission grids. In ... more Accurate monitoring tools are fundamental for the proper operation of the transmission grids. In this context, an essential requirement for the transmission system operator is the availability of accurate knowledge on transmission line and transformer characteristics. Despite the high accuracy of the increasingly used Phasor Measurements Units (PMUs), there are still significant issues associated with the knowledge of the actual line parameters and on the actual tap changer ratio. In this regard, the paper proposes a method to estimate simultaneously the line parameters, the tap changer ratio, and the systematic measurement errors associated with the instrument transformers. With an appropriate model of the measurement chain, which includes the uncertainties associated with instrument transformers and PMUs, a linear formulation of the line and transformer constraint equations can be applied and accurate results can be obtained. The validity of the proposed method is confirmed by different types of tests performed on the IEEE 14-bus test system.
Journal of Cosmology and Astroparticle Physics, 2021
Future liquid-argon DarkSide-20k and Argo detectors, designed for direct dark matter search, will... more Future liquid-argon DarkSide-20k and Argo detectors, designed for direct dark matter search, will be sensitive also to core-collapse supernova neutrinos, via coherent elastic neutrino-nucleus scattering. This interaction channel is flavor-insensitive with a high-cross section, enabling for a high-statistics neutrino detection with target masses of ∼50 t and ∼360 t for DarkSide-20k and Argo respectively. Thanks to the low-energy threshold of ∼0.5 keVnr achievable by exploiting the ionization channel, DarkSide-20k and Argo have the potential to discover supernova bursts throughout our galaxy and up to the Small Magellanic Cloud, respectively, assuming a 11-M☉ progenitor star. We report also on the sensitivity to the neutronization burst, whose electron neutrino flux is suppressed by oscillations when detected via charged current and elastic scattering. Finally, the accuracies in the reconstruction of the average and total neutrino energy in the different phases of the supernova burst,...
Aria is a plant hosting a$${350}\,\hbox {m}$$350mcryogenic isotopic distillation column, the tall... more Aria is a plant hosting a$${350}\,\hbox {m}$$350mcryogenic isotopic distillation column, the tallest ever built, which is being installed in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. It was designed to reduce the isotopic abundance of$${^{39}\hbox {Ar}}$$39Arin argon extracted from underground sources, called Underground Argon (UAr), which is used for dark-matter searches. Indeed,$${^{39}\hbox {Ar}}$$39Aris a$$\beta $$β-emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors. In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of the isotopic cryogenic distillation of nitrogen with a prototype plant.
Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area ... more Phasor measurement units (PMUs), which are the key components of a synchrophasor-based wide area monitoring system (WAMS), were historically conceived for transmission networks. The current trend to extend the benefits of the synchrophasor technology to distribution networks requires the PMU to also provide trustworthy information in the presence of signals that can occur in a typical distribution grid, including the presence of severe power quality (PQ) issues. In this framework, this paper experimentally investigates the performance of PMUs in the presence of one of the most important PQ phenomena, namely the presence of voltage fluctuations that generate the disturbance commonly known as flicker. The experimental tests are based on an ad-hoc high-accuracy measurement setup, where the devices under test are considered as “black boxes” to be characterized in the presence of the relevant signals. Two simple indices are introduced for the comparison among the different tested PMUs. T...
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Papers by Sara Sulis