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Design of a robust PID-PSS for an uncertain power system with simplified stability conditions

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Protection and Control of Modern Power Systems 2020年第1期5卷 222-237页

作者： vijaya Lakshmi A.S.v Ramalinga Raju Manyala siva kumar Mangipudi Department of EEE G.V.P College of Engineering for WomenVisakhapatnamIndia Department of EEE JNTU KakinadaKakinadaIndia Department of EEE Gudlavalleru Engineering CollegeGudlavalleruAndhra PradeshIndia

In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low FrequencyOscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, anoptimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB)power system is proposed. The interval modelling captures the wide variations of operating conditions in boundsof system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for anSMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance ofan SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided inMATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods inthe literature when the system is subjected to different uncertainties. The simulation results and performance errorvalues show the effectiveness of the proposed robust PID-PSS controller.

关键词： Low frequency oscillations Uncertainty Power system stabilizer Robust controller Interval systems

volumetric, Ultrasonic and Transport Properties of Binary Liquid Mixtures Containing Dimethyl Formamide at 303.15 K

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Chinese Journal of Chemistry 2007年第1期25卷 32-43页

作者： SYAMALA, vardhana RAJA SEKHAR, Damaramadugu siva kumar, Kasibhatta vENKATESWARLU, Ponneri Thermochemical Laboratories Department of Chemistry Sri Venkateswara University Tirupati 517 502 India Department of Chemistry SVArts College Tirupati 517 502 India

Excess volumes （v^E）, ultrasonic velocities （u）, isentropic compressibility （△Ks） and viscosities （η） for the binary mixtures of dimethyl formamide （DMF） with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at 303.15 K were studied. Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2- and 1,3-dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4-trichlorobenzene, o-nitrotoluene and m-nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility （Ks） has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic com- pressibility （△Ks） from ideal behavior was also calculated. AKs values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory （FLT） and Collision Factor Theory （CFT）. The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.

关键词： excess volume, dimethyl formamide, interferometer, sound velocity, viscosity molecular interaction

Structure, photocatalytic and antibacterial activity study of Meso porous Ni and S co-doped TiO2 nano material under visible light irradiation

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1630-1641页

作者： K.v.Divya Lakshmi T.siva Rao J.Swathi Padmaja I.Manga Raju M.Ravi kumar Department of Inorganic and Analytical Chemistry Andhra University

Undoped and Ni–S co-doped mesoporous TiO2 nano materials were synthesized by using sol–gel *** characteristic features of as prepared catalyst samples were investigated using various advanced spectroscopic and analytical *** characterization results of the samples revealed that all the samples exhibited anatase phase(XRD),decreasing band gap(2.68 ev)(Uv–vis-DRS),small particle size(9.2 nm)(TEM),high surface area(142.156 m^2·g^-1)(BET),particles with spherical shape and smooth morphology(SEM);there is a frequency shift observed for co-doped sample(FT-IR)and the elemental composition electronic states and position of the doped elements(Ni and S)in the TiO2 lattice analyzed by XPS and *** results supported the photocatalytic degradation of Bismarck Brown Red(BBR)achieved with in 110 min and also exhibited the antibacterial activity on Staphylococcus aureus(MTCC-3160),Pseudomonas fluorescence(MTCC-1688)under visible light irradiation.

关键词： Sol–gel Ni–S co-doped TiO2 Photocatalysis under visible light Degradation of Bismarck Brown Red Antibacterial activity

Mechanical properties of Ni_(0.83)Co_(0.15)Cu_(0.02)Fe_(1.9)O_(4-δ)+PbZr_(0.52)Ti_(0.48)O_(3)particulate composites by composite oscillator technique and the correlation with the results of magnetoelectric properties

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Journal of Advanced Ceramics 2012年第4期1卷 317-326页

作者： M.venkata RAMANA M.Penchal REDDY N.Ramamanohar REDDY B.S.MURTY K.v.siva kumar Shenhua SONG Shenzhen Key Laboratory of Advanced Materials Department of Materials Science and EngineeringShenzhen Graduate SchoolHarbin Institute of TechnologyShenzhen 518055China Department of Physics Changwon National UniversityChangwonRepublic of Korea Ceramic Composite Materials Laboratory Department of PhysicsSri Krishnadevaraya UniversityAnantapur 515003India Nanotechnology Laboratory Department of Metallurgical and Materials EngineeringIndian Institute of TechnologyChennai 600036India

The xNi_(0.83)Co_(0.15)Cu_(0.02)Fe_(1.9)O_(4-δ)+PbZr_(0.52)Ti_(0.48)O_(3)(PZT)particulate magneto ferroelectric composites with x=0,0.1,0.2,0.3,0.4,0.5 and 0.6 mole fraction were prepared by conventional ceramic double sintering *** presence of two phases(perovskite structure of ferroelectric phase and spinal structure of ferromagnetic phase)was confirmed by X-ray *** magnetoelectric(ME)property of the particulate composites was determined at room temperature as a function of intensity of magnetic *** temperature variation of the longitudinal modulus(L)and the internal friction(Q−1)of these particulate composites at 104.3 kHz was studied in the wide temperature range 30-420℃.The temperature variation of the longitudinal modulus in each composition of these particulate composites showed two abrupt *** minimum coincided with the ferroelectric-paraelectric Curie transition temperature(θE)and the other with the ferromagnetic-paramagnetic Curie transition temperature(θM).The internal friction measurement also showed two sharp peaks in each composition corresponding to those temperatures where the minima were noticed in the temperature variation of the longitudinal modulus behaviour.

关键词： X-ray diffraction magnetoelectric effect piezoelectric coefficient internal friction Curie transition temperature

SYNTHESIS OF LEAD FREE SODIUM BISMUTH TITANATE(NBT)CERAMIC BY CONvENTIONAL AND MICROWAvE SINTERING METHODS

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Journal of Advanced Dielectrics 2011年第1期1卷 71-77页

作者： M.vENKATA RAMANA S.ROOPAS KIRAN N.RAMAMANOHAR REDDY K.v.siva kumar v.R.K.MURTHY B.S.MURTY Ceramic Composite Materials Laboratory Department of Physics Sri Krishnadevaraya UniversityAnantapur 515003India Microwave Laboratory Department of Physics Indian Institute of Technology Chennai 600036India Nanotechnology Laboratory Department of Metallurgical and Materials Engineering Indian Institute of Technology Chennai 600036 India

Dielectric studies were carried out on a lead free Sodium Bismuth Titanate,NBT,(Na_(0.5)Bi_(0.5)TiO_(3))*** material was synthesized by conventional ceramic method(CS)and microwave sintering(MS).The presence of single phase has been confirmed by X-ray diffraction and scanning electron microscopy of NBT *** later technique(MS)resulted in material with high density,dielectric properties and improved *** transition temperature was observed slightly higher for microwave sintered(MS)*** modulus measurements are very sensitive property to identify the phase transitions in *** modulus(L)measurements were also employed on these samples in the frequency 136 kHz and can be studied in the wide temperature range 30℃to 400℃.The elastic behavior(L)showed a break at two temperatures(~200℃and 350℃)in both the conventional and microwave sintered *** NBT ceramics,permittivity anomalies are connected to modulus *** results are correlated with the dielectric *** behavior explained in the light of structural phase transitions in the ferroelectric ceramics.

关键词： Microwave sintering NBT X-ray diffractometer scanning electron microscopy dielectric properties longitudinal modulus

A Study on vibrational Spectra of PH3 and NF3: An Algebraic Approach

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Open Journal of Microphysics 2013年第2期3卷 47-51页

作者： S. R. Karumuri G. Srinivas vijayasekhar Jaliparthi K. Sunil Babu v. Sundara siva kumar A. Hanumaiah Department of Electronics & Instrumentation Engineering Lakireddy Bali Reddy College of Engineering Vijayawada India Department of Physics KL University Guntur India Research Scholar Department of Mathematics Jawaharlal Nehru Technological University Kakinada India Department of Physics Miracle Engineering College Bhogapuram India Department of Electronics & Instrumentation Rajeev Gandhi Memorial Engineering College Nandyal India Department of Physics Lara’s Vignan Institute of Technology and Science Vadlamudi India

With the new theoretical approach i.e. lie algebraic approach, we have calculated the infrared spectra of Phosphine in the range from 3000 cm-1 to 9500 cm-1 and Nitrogen Trifluoride in the range from 900 cm-1 to 4500 cm-1. The model Hamiltonian, so constructed, seems to describe the P-H and N-F stretching modes accurately with only four numbers of parameters.

关键词： vibrational Spectra Lie Algebraic Model Hamiltonian

Structure,photocatalytic and antibacterial activity study of Meso porous Ni and S co-doped TiO₂ nano material under visible light irradiation

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