PMU-based informational support of power system control tasks

Up-to-date wide area measurement systems (WAMS) based on phasor measurement units (PMU) appeared at the very end of the 20th century. Under present-day conditions, WAMS serve as the basis for information-measuring systems, which significantly improve power system control and operation. In practice, WAMS are mostly used for power system stability control and transient monitoring and visualization. This paper discusses the new opportunities for power system control quality improvement, resulting from PMU application for power system steady-state parameters' assessment. Firstly, better control is provided by online equivalent circuit parameters' identification using PMU measurement data and taking into account FACTS and other shunt and series compensation equipment. Secondly, the paper addresses the problems of "nodal" identification, which have taken on great importance recently due to the intensive development of small-scaled distributed generation. Based on PMU measurements of nodal voltages and incident transmission lines' electric currents, one can obtain online steady-state load characteristics, which can be used for dispatch control applications. Moreover, PMUs provide superaccelerated power flow calculations, which are of crucial importance for emergency automation, adjusted for prior operation. Such principles of emergency automation consist of the quick determination of control actions, aimed at power system stability maintenance in cases of any programmed faults' occurrence. It is known that such control is carried out by means of power flow calculations based on remote metering data. The proposed application and allocation of PMUs in the power system by means of combinatorial matrix transformation to triangle form give the possibility to perform accelerated node-voltage analysis without equivalent circuit simplification. All the calculations are verified using IEEE test networks. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Electrical discharges in the atmosphere of Venus

Data received from Venera 11 and 12 experiments involving the electrical activity of the atmosphere of Venus show that the electrical discharges occur in the cloud layer. Their energy is roughly the same as in terrestrial lightning, but with a pulse repetition frequency of the discharges which is much greater

An Effect of Co–W Barrier Sublayer on the Functional Characteristics of Au–Ru Contact Coatings

Funding Information: Funding: This work was supported by the Ministry of Education and Science of the Russian Federation in the frame of the state assignment FSSN-2020-0003. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The performance characteristics (microhardness, porosity, roughness, and transient resistance) of Au–Ru coatings with and without the Co–W alloy barrier sublayer electrodeposited on the surface of contact blades of commercially produced reed switches were investigated. It was found that the barrier sublayer reduces the average roughness of the coatings without significant change in their porosity. The Au–Ru coatings without sublayer exhibited a greater variation in the transient resistance during an increase in the pressing force. The service time of reed switches with the barrier sublayer increased in both testing modes: in low-power (50 mV, 5 µA, 50 Hz) by more than 4 × 106 switching cycles, and in mean-power (12 V, 0.25 A, 50 Hz) by more than 1.8 × 106 switching cycles.publishersversionpublishe

Dynamics of the Free Surface of a Conducting Liquid in a Near-Critical Electric Field

Near-critical behavior of the free surface of an ideally conducting liquid in an external electric field is considered. Based on an analysis of three-wave processes using the method of integral estimations, sufficient criteria for hard instability of a planar surface are formulated. It is shown that the higher-order nonlinearities do not saturate the instability, for which reason the growth of disturbances has an explosive character.Comment: 19 page

Baby MIND: A magnetised spectrometer for the WAGASCI experiment

The WAGASCI experiment being built at the J-PARC neutrino beam line will measure the difference in cross sections from neutrinos interacting with a water and scintillator targets, in order to constrain neutrino cross sections, essential for the T2K neutrino oscillation measurements. A prototype Magnetised Iron Neutrino Detector (MIND), called Baby MIND, is being constructed at CERN to act as a magnetic spectrometer behind the main WAGASCI target to be able to measure the charge and momentum of the outgoing muon from neutrino charged current interactions.Comment: Poster presented at NuPhys2016 (London, 12-14 December 2016). Title + 4 pages, LaTeX, 6 figure

Baby MIND Experiment Construction Status

Baby MIND is a magnetized iron neutrino detector, with novel design features, and is planned to serve as a downstream magnetized muon spectrometer for the WAGASCI experiment on the T2K neutrino beam line in Japan. One of the main goals of this experiment is to reduce systematic uncertainties relevant to CP-violation searches, by measuring the neutrino contamination in the anti-neutrino beam mode of T2K. Baby MIND is currently being constructed at CERN, and is planned to be operational in Japan in October 2017.Comment: Poster presented at NuPhys2016 (London, 12-14 December 2016). 4 pages, LaTeX, 7 figure

Synchronization of the Distributed Readout Frontend Electronics of the Baby MIND Detector

Baby MIND is a new downstream muon range detector for the WGASCI experiment. This article discusses the distributed readout system and its timing requirements. The paper presents the design of the synchronization subsystem and the results of its test

Baby MIND: A magnetized segmented neutrino detector for the WAGASCI experiment

T2K (Tokai-to-Kamioka) is a long-baseline neutrino experiment in Japan designed to study various parameters of neutrino oscillations. A near detector complex (ND280) is located 280~m downstream of the production target and measures neutrino beam parameters before any oscillations occur. ND280's measurements are used to predict the number and spectra of neutrinos in the Super-Kamiokande detector at the distance of 295~km. The difference in the target material between the far (water) and near (scintillator, hydrocarbon) detectors leads to the main non-cancelling systematic uncertainty for the oscillation analysis. In order to reduce this uncertainty a new WAter-Grid-And-SCintillator detector (WAGASCI) has been developed. A magnetized iron neutrino detector (Baby MIND) will be used to measure momentum and charge identification of the outgoing muons from charged current interactions. The Baby MIND modules are composed of magnetized iron plates and long plastic scintillator bars read out at the both ends with wavelength shifting fibers and silicon photomultipliers. The front-end electronics board has been developed to perform the readout and digitization of the signals from the scintillator bars. Detector elements were tested with cosmic rays and in the PS beam at CERN. The obtained results are presented in this paper.Comment: In new version: modified both plots of Fig.1 and added one sentence in the introduction part explaining Baby MIND role in WAGASCI experiment, added information for the affiliation

Solar neutrino detection in a large volume double-phase liquid argon experiment

Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the "neutrino floor" (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.Comment: 21 pages, 7 figures, 6 table