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A robust composite wide area control of a DFIG wind energy system for damping inter-area oscillations

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Protection and Control of Modern Power systems 2020年第1期5卷 280-289页

作者： ayyarao s.l.v.tummala Department of EEE GMR Institute of TechnologyRajam 532127India

This paper presents a novel composite wide area control of a DFIG wind energy system which combines the Robust Exact Differentiator(RED)and Discontinuous Integral(DI)control to damp out inter-area *** generates the real-time differentiation of a relative speed signal in a noisy environment while DI control,an extension to a twisting algorithm and PID control,develops a continuous control signal and hence reduces *** proposed control is robust to disturbances and can enhance the overall stability of the *** proposed composite sliding mode control is evaluated using a modified benchmark two-area power system model with wind energy *** results under various operating scenarios show the efficacy of the proposed approach.

关键词： DFIG Wide area control Wind energy system sliding mode control

Observer based sliding mode frequency control for multi-machine power systems with high renewable energy

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Journal of Modern Power systems and Clean Energy 2018年第3期6卷 473-481页

作者： ayyarao s.l.v.tummala Ravikiran INAPAKURTHI P.v.RAMANARAO Department of Electrical and Electronic Engineering GMR Institute of Technology Department of Electrical and Electronic Engineering University College of Engineering and TechnologyANUGuntur India

With the global consciousness of climate change, renewable energy systems are prioritized over the conventional energy systems. The deep injection of renewables into the power systems is creating several challenges to the grid due to wide variations in their output power depending on the time of the day, weather etc. Of these challenges, frequency change plays a vital role in maintaining the power quality. This paper presents a novel sliding mode controller with non-linear disturbance observer to effectively mitigate the wide changes in the frequency. A sliding mode surface based on estimated disturbance along with states is designed. A sliding mode control law is proposed to compensate disturbances including variations in renewables, load and parameters under mismatched uncertainties. The proposed observer based controller is tested for three area multi-machine power system in MATlAB/simulink. The simulated results proved to alleviate the frequency variations effectively compared to the conventional controllers.

关键词： Renewable energy Disturbance observer sliding mode control Disturbance compensation Frequency control

Effect of Ta_(2)O_(5)nanoparticles on bioactivity,composition,structure,in vitro and in vivo behavior of PEO coatings on Mg-alloy

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Journal of Magnesium and Alloys 2024年第6期12卷 2360-2379页

作者： D.v.Mashtalyar I.M.Imshinetskiy v.v.Kashepa K.v.Nadaraia M.A.Piatkova A.I.Pleshkova K.A.Fomenko A.Yu.Ustinov s.l.sinebryukhov s.v.Gnedenkov Institute of Chemistry Far Eastern BranchRussian Academy of SciencesVladivostok690022Russia Far Eastern Federal University Vladivostok690950Russia Regional Clinical Dermatovenerological Dispensary Vladivostok690033Russia

The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium *** obtained coatings demonstrate in vivo biocompatibility and in vitro *** to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the *** was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in *** on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen *** results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.

关键词： Plasma electrolytic oxidation Bioactive coatings Tantalum pentoxide simulated body fluid(sBF) Apatite formation Histology

Antibacterial HA-coatings on bioresorbable Mg alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1965-1985页

作者： K.v.Nadaraia D.v.Mashtalyar M.A.Piatkova A.I.Pleshkova I.M.Imshinetskiy M.s.Gerasimenko E.A.Belov v.v.Kumeiko D.N.Kozyrev K.A.Fomenko v.v.Mostovaya B.R.Torpanov A.R.Biktimirov I.s.Osmushko s.l.sinebryukhov s.v.Gnedenkov Institute of Chemistry FEB RAs 159 Pr.100-letiya VladivostokaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia A.v.Zhirmunsky National scientific Center of Marine Biology FEB RAs 17 St.PalchevskogoVladivostok 690041Russia Regional Clinical Dermatovenerological Dispensary 18 V St.GamarnikaVladivostok 690033Russia NMIC“Treatment and Rehabilitation Center” 3 Ivankovskoe highwayMoscow 125367Russia

In this study,a calcium-phosphate coating was formed on a Mg-Mn-Ce alloy by the plasma electrolytic oxidation(PEO).The antibiotic vancomycin,widely used in the treatment of infections caused by staphylococcus aureus(***),was impregnated into the *** with vancomycin showed high bactericidal activity against *** mechanical and electrochemical properties of the formed coatings were studied,as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were *** to sEM,EDs,XRD and XPs data,coatings had a developed morphology and contained hydroxyapatite,which indicates high *** analysis of roughness of coatings without and with vancomycin did not reveal any differences,confirming the high roughness of the *** electrochemical tests,an increase in corrosion resistance by more than two times after the application of PEO coatings was *** to the results of an in vivo study,after 28 days of the implantation of samples with calcium phosphate PEO coating and vancomycin,no signs of inflammation were observed,while an inflammatory reaction developed in the area of implantation of bare alloy,followed by *** release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day *** the experiment,no significant deviations in the condition and behavior of the animals were observed;clinical tests did not reveal a systemic toxic reaction.

关键词： Bioactive coatings Biocompatibility Mg alloy Plasma electrolytic oxidation Hydroxyapatite vancomycin

sANC Monte Carlo programs for small-angle Bhabha scattering

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Chinese Physics C 2024年第4期48卷 14-19页

作者： A.B.Arbuzov s.G.Bondarenko I.R.Boyko l.v.Kalinovskaya A.A.Kampf R.R.sadykov v.l.Yermolchyk Bogoliubov laboratory of Theoretical Physics JINRDubna141980 Russia Dzhelepov laboratory of Nuclear Problems JINRDubna141980 Russia Dubna state University Dubna141982 Russia

luminosity monitoring at e^(+)e^(−)colliders was investigated using sANC Monte Carlo event generator RenesANCe and integrator MCsANC for simulation of Bhabha scattering at low *** are presented for center-of-mass energies of the Z boson resonance and at 240 Gev for the conditions of typical luminosity *** is shown that bremsstrahlung events with extremely low electron scattering angles are relevant to match the precision tags of future electron-positron colliders.

关键词： luminosity Bhabha scattering QED Monte Carlo simulation

Ion heat transport in electron cyclotron resonance heated l-mode plasma on the T-10 tokamak

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Plasma science and Technology 2024年第4期26卷 52-60页

作者： v.A.KRUPIN M.R.NURGAlIEv A.R.NEMETs I.A.ZEMTsOv s.D.sUNTsOv T.B.MYAlTON D.s.sERGEEv N.A.sOlOvEv D.v.sARYCHEv D.v.RYJAKOv s.N.TUGARINOv N.N.NAUMENKO National Research Centre“Kurchatov Institute” Moscow 123182Russia Bauman Moscow state Technical University Moscow 105005Russia Institution“Project Center ITER” Moscow 123098Russia JsC“sOlAR” Minsk 220034Belarus

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak l-mode electron cyclotron resonance heating ion heat transport

Cluster Analysis of the Roma-BZCAT Blazars

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Research in Astronomy and Astrophysics 2024年第5期24卷 117-139页

作者： Dmitry O.Kudryavtsev Yulia v.sotnikova vladislav A.stolyarov Timur v.Mufakharov valery v.vlasyuk Margarita l.Khabibullina Alexander G.Mikhailov Yulia v.Cherepkova special Astrophysical Observatory of the Russian Academy of sciences Nizhny Arkhyz 369167Russia Astrophysics Group Cavendish LaboratoryUniversity of CambridgeCambridge CB3 OHEUK Kazan Federal University 18 Kremlyovskaya StKazan 420008Russia

Based on the collected multiwavelength data, namely in the radio(Nvss, FIRsT, RATAN-600), IR(WIsE),optical(Pan-sTARRs), Uv(GAlEX), and X-ray(ROsAT, swift-XRT) ranges, we have performed a cluster analysis for the blazars of the Roma-BZCAT catalog. Using two machine learning methods, namely a combination of PCA with k-means clustering and Kohonen's self-organizing maps(sOMs), we have constructed an independent classification of the blazars(five classes) and compared the classes with the known Roma-BZCAT classification(FsRQs, Bl lacs, galaxy-dominated Bl lacs, and blazars of an uncertain type) as well as with the high synchrotron peaked(HsP) blazars from the 3HsP catalog and blazars from the TevCat catalog. The obtained groups demonstrate concordance with the Bl lac/FsRQ classification along with a continuous character of the change in the properties. The group of HsP blazars stands out against the overall distribution. We examine the characteristics of the five groups and demonstrate distinctions in their spectral energy distribution shapes. The effectiveness of the clustering technique for objective analysis of multiparametric arrays of experimental data is demonstrated.

关键词： methods data analysis-galaxies active-(galaxies:)Bl lacertae objects general

Highly Defective Dark TiO_(2) Modified with Pt: Effects of Precursor Nature and Preparation Method on Photocatalytic Properties

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Transactions of Tianjin University 2024年第2期30卷 198-209页

作者： E.D.Fakhrutdinova O.A.Reutova T.A.Bugrova I.Yu.Ovsyuk l.s.Kibis O.A.stonkus D.B.vasilchenko O.v.vodyankina v.A.svetlychnyi National Research Tomsk state University TomskRussia 634050 Novosibirsk state University NovosibirskRussia 630090 Boreskov Institute of Catalysis NovosibirskRussia 630090 Nikolaev Institute of Inorganic Chemistry NovosibirskRussia 630090

The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (sMsI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the sMsI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.

关键词： Dark(black)TiO_(2) Pulsed laser ablation Platinum reduction method Precursor type Photocatalysis Hydrogen evolution reaction

Modified vector controlled DFIG wind energy system based on barrier function adaptive sliding mode control

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Protection and Control of Modern Power systems 2019年第1期4卷 34-41页

作者： tummala s.l.v.ayyarao Department of EEE GMR Institute of TechnologyRajam532127India

Increased penetration of wind energy systems has serious concerns on power system stability. In spite of several advantages, doubly fed induction generator (DFIG) based wind energy systems are very sensitive to grid disturbances. DFIG system with conventional vector control is not robust to disturbances as it is based on PI controllers. The objective of this paper is to design a new vector control that is robust to external disturbances. To achieve this, inner current loop of the conventional vector control is replaced with sliding mode control. In order to avoid chattering effect and achieve finite time convergence, the control gains are selected based on positive semi-definite barrier function. The proposed barrier function adaptive sliding mode (BFAsMC) is evaluated by testing it on a benchmark multi-machine power system model under various operating conditions. The simulated results show that the proposed method is robust to various disturbances.

关键词： Doubly fed induction generator(DFIG) Wind power generation sliding mode control Robust control