Application of Hybrid Differential Evolution–Grey Wolf Optimization Algorithm for Automatic Generation Control of a Multi-Source Interconnected Power System Using Optimal Fuzzy–PID Controller

This paper deals with an optimal hybrid fuzzy-Proportional Integral Derivative (fuzzy-PID) controller optimized by hybrid differential evolution–Grey Wolf optimization algorithm for automatic generation control of an interconnected multi-source power system. Here a two area system is considered; each area is provided with three types of sources namely a thermal unit with reheat turbine, a hydro unit and a gas unit. The dynamic performance of the system is analyzed under two cases: with AC tie-line and with AC-DC tie-line. The efficiency and effectiveness of the proposed controller is substantiated equally in the two cases. The sturdiness of the system is proved by varying the values of the system parameters. The supremacy of the recommended work is additionally ascertained by comparison with the recently published results like differential evolution optimized PID Controller and hybrid Local Unimodal Sampling-Teaching Learning based Optimization (LUS-TLBO) optimized fuzzy-PID controller. The dynamic performance of the system is observed in terms of settling time, peak overshoot and peak undershoot. Finally the analysis is extended by applying the proposed control technique in two different models namely (i) A three area unequal thermal system considering proper generation rate constraints (GRC) and (ii) A three area hydro-thermal system with mechanical hydro governor. These test results reveal the adaptability of the proposed method in multi-area interconnected power system.     

A new technique for computation of closest saddle-node bifurcation point of power system using real coded genetic algorithm

Estimation of voltage stability margin is essential for operation of the system with an adequate security margin. In this paper, a new technique to determine the worst case loading margin, i.e., shortest distance to voltage instability is developed. The problem of determining the closest saddle-node bifurcation point (CSNBP) is formulated as an optimization problem and solved using Real Coded Genetic Algorithm (RCGA). The method is capable of handling various operational constraints and can determine the CSNBP accurately even if the transfer limit surface is not smooth. The proposed approach has been applied on a simple radial system, IEEE 14-bus and IEEE 57-bus systems. The developed method has been compared with the method based on Particle Swarm Optimization. Simulation results show the validity and feasibility of the proposed method.     

Magnetoelectric,Raman, and XPS Properties of Pb0.7Sr0.3[(Fe2/3Ce1/3)0.012Ti0.988]O3 and Pb0.7Sr0.3[(Fe2/3La1/3)0.012Ti0.988]O3 Nanoparticles

The Pb_0.7Sr_0.3[(Fe_2/3Ce_1/3)_0.012Ti_0.988]O₃ (PSFCT) and Pb_0.7Sr_0.3[(Fe_2/3La_1/3)_0.012Ti_0.988]O₃ nanoparticles were prepared by chemical synthesis route using polyvinyl alcohol as surfactant. X-ray diffraction pattern has been used to analyze the phase structure and average particles size. The phase structure is also confirmed by Raman spectra. The chemical states of Pb²⁺, Sr²⁺, Fe³⁺; Ti⁴⁺, Ce³⁺, La³⁺, and oxygen ions have been analyzed by X-ray photoelectron spectroscopy. The magnetoelectric coupling effect is confirmed by magnetic phase transition near ferroelectric phase-transition temperature. The magnetoelectric effect is also confirmed by measuring the value of magnetoelectric coefficient (α _E) as the function of applied dc magnetizing field under the influence of ac magnetic field of 10 Oe and frequencies of 847 and 997 Hz. The higher value of α _E is observed in PSFCT sample.     

Structural, Dielectric, Ferroelectric and Magnetic Properties of Bi0.80A0.20FeO3 (A=Pr,Y) Multiferroics

Here we studied the effect of homovalent Pr³⁺ and Y³⁺ substitution on the crystal structure, dielectric, electronic polarization and magnetic properties of the BiFeO₃ multiferroic ceramic. The samples were synthesized by the conventional solid-state reaction method. Pure phase formation of Pr doped BiFeO₃ (BFO) has been obtained, while Y³⁺ doped BFO has shown a few impurity peaks. It has shown that the crystal structure of the compounds is described within the space group R3c. Pr³⁺ modified BFO has shown an anomaly in the ε _r vs. T plot around and a Néel temperature ‘T _N’～370 ^°C. P–E hysteresis loops have shown higher value of remnant polarization for Pr³⁺ modified BFO. Magnetic properties of ceramics are determined by the ionic radius of the substituting element. Experimental results propose that the increase in the radius of A-site ion leads to effective suppression of the spiral spin structure of BiFeO₃, resulting in the appearance of net magnetization.     

Genetic programming‐based approach to elucidate biochemical interaction networks from data

Biochemical systems are characterised by cyclic/reversible reciprocal actions, non‐linear interactions and a mixed relationship structures (linear and non‐linear; static and dynamic). Deciphering the architecture of such systems using measured data to provide quantitative information regarding the nature of relationships that exist between the measured variables is a challenging proposition. Causality detection is one of the methodologies that are applied to elucidate biochemical networks from such data. Autoregressive‐based modelling approach such as granger causality, partial directed coherence, directed transfer function and canonical variate analysis have been applied on different systems for deciphering such interactions, but with limited success. In this study, the authors propose a genetic programming‐based causality detection (GPCD) methodology which blends evolutionary computation‐based procedures along with parameter estimation methods to derive a mathematical model of the system. Application of the GPCD methodology on five data sets that contained the different challenges mentioned above indicated that GPCD performs better than the other methods in uncovering the exact structure with less false positives. On a glycolysis data set, GPCD was able to fill the ‘interaction gaps’ which were missed by other methods.Inspec keywords: autoregressive processes, biochemistry, biology computing, genetic algorithms, parameter estimation, transfer functionsOther keywords: elucidate biochemical interaction networks, biochemical systems, cyclic‐reversible reciprocal actions, nonlinear interactions, autoregressive‐based modelling, granger causality, transfer function, canonical variate analysis, genetic programming‐based causality detection methodology, GPCD methodology, mathematical model, parameter estimation methods     

Interparticle Collision of Particle Composites—Finite and Discrete Element Simulations

Three different cases of interparticle collisions were simulated to observe the fragmentation mechanisms of composite particles. It was found that the cracking mechanism in interparticle collisions is different from that observed in particle-wall collisions. By means of DEM simulations, it was observed that the primary interparticle bonds break in both tension and shear. Depending on the type of interparticle collisions, cracks and fragments are generated. In general, finer fragments are generated around the impact site of the particles and are surrounded by larger fragments. From DEM simulations, it was found for the most part that the impacting particles exhibit more damage than the stationary particles. The symmetrical loading showed almost the same amount of damage to both types of particles. The discontinuous nature of the material and the unsymmetrical loading caused unsymmetrical damages (crack patterns). In unsymmetrical loadings, the impacting particle was more damaged and had more cracks than the stationary particle.     

Studies on textural properties of lanthanum-exchanged Y zeolites as promising materials for value upgradation of Jatropha oil

A series of La (Lanthanum)-exchanged Y zeolites have been prepared and the changes occurred in textural properties of the material have been characterized by XRD, SEM, surface area, pore volume, and pore size distribution techniques. La loading was observed to enhance not only acidity but also the porosity (in terms of mesopores) of the Y zeolite. The parent HY and three La loaded samples (LaHY-1, LaHY-2, and LaHY-3) have been studied for the changes in properties occurred by La loading and their collective influence on the catalytic performance toward the Jatropha oil to gasoline (JTG) reaction. All the catalysts exhibited 100 % conversion but the performance toward the gasoline selectivity is increased in the order of HY < LaHY-3 < LaHY-1 < LaHY-2. Detailed analysis of the results indicated that the increase in porosity (both in micro- and meso-pore region) rather than the acidity is responsible for enhanced catalytic performance of the LaHY-2 catalyst. This particular catalyst also exhibited lower coke formation and prolonged time-on-stream stability in the JTG reaction ascribed to the facile diffusion of the product molecules facilitated in mesopores.     

Rietveld analysis, magnetic, vibrational and impedance properties of (Bi1−xPrx)(Fe1−xZrx)O3 ceramics

(Bi_1?xPr_x)(Fe_1?xZr_x)O₃ ceramics with x = 0.03, 0.06 and 0.10 were prepared via solid state reaction route. X-ray diffraction and Raman spectra of the ceramics were recorded for calculating its lattice parameters and structural analysis. Magnetic studies indicated a significant enhancement in magnetization of (Bi_1?xPr_x)(Fe_1?xZr_x)O₃ ceramics with maximum remnant magnetization of 0.12 emu g^?1 for x = 0.06 sample. Fourier transform infrared spectra and Rietveld analysis confirmed the change in bond length arising due to Pr and Zr codoping. Dielectric measurements showed dielectric anomaly around Neel temperature, indicating magnetoelectric coupling in the samples as well as the dielectric relaxation for higher doping. The effect of Pr and Zr codoping on the impedance and modulus behavior of BiFeO₃ lattice is discussed. The frequency dependence of electric modulus and impedance of the material show the presence of non-Debye relaxation in the samples. All samples showed energy band gap in the range 2.16–2.0 eV, indicating possibility of optical activity in visible range and making it suitable for photocatalytic applications.     

Magnetoelectric coupling enhancement in lead-free BCTZ–xNZFO composites

Journal of Materials Science: Materials in Electronics - In this work, (1 ?&nbsp;x)Ba0.85Ca0.15Zr0.1Ti0.9O3&nbsp;(BCZT)–xNi0.8Zn0.2Fe2O4&nbsp;(NZFO), where...     

Statistical analysis for fatigue life evaluation of woven E-glass/epoxy composite laminates containing off-centre interacting circular holes

Mechanics of Time-Dependent Materials - Fatigue behaviour of woven E-glass/epoxy composite laminates containing off-centre interacting circular holes was determined under sinusoidal loading in...