Optimisation of corona ring design for composite insulator strings

2019 ◽  
Vol 38 (1) ◽  
pp. 232-246
Author(s):  
Kalaiselvi Aramugam ◽  
Hazlee Azil Illias ◽  
Yern Chee Ching
Keyword(s):  
Electric Field ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
String Model ◽  
Vertical Position ◽  
Element Analysis ◽  
Content Type ◽  
Electric Field Magnitude ◽  
Field Magnitude ◽  
Corona Ring

PurposeThe purpose of this paper is to propose an optimum design of a corona ring for insulator strings using optimisation techniques, which are gravitational search algorithm (GSA) and imperialist competitive algorithm (ICA).Design/methodology/approachAn insulator string model geometry with a corona ring was modelled in a finite element analysis software, and it was used to obtain the electric field distribution in the model. The design was optimised using GSA and ICA. The variables were the corona ring diameter, ring tube diameter and vertical position of the ring along the insulator string.FindingsUsing optimisation method, the minimum electric field magnitude on the insulator string with a corona ring design is lower than without using optimisation method. GSA yields better results than ICA in terms of the optimised corona ring design.Practical implicationsThe proposed methods can help in improvement of corona ring design in reducing the electric field magnitude on the energised end of insulator strings.Originality/valueA new method to design an optimum corona ring for insulator strings, which is using optimisation methods, has been developed in this work.

scholarly journals Optimisation of zinc oxide surge arrester design using gravitational search algorithm and imperialist competitive algorithm

2019 ◽  
Vol 13 (3) ◽  
pp. 853
Author(s):  
Syahirah Abd Halim ◽  
Azah Mohamed ◽  
Nor Azwan Mohamed Kamari ◽  
Afida Ayob ◽  
Ab Halim Abu Bakar ◽  
...  
Keyword(s):  
Electric Field ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Imperialist Competitive Algorithm ◽  
Design Parameters ◽  
Element Analysis ◽  
Field Stress ◽  
Competitive Algorithm ◽  
Surge Arresters ◽  
Gravitational Search

Reducing electric field stress near the energised end of surge arresters is very important because it may increase the lifetime of the highly stressed ZnO column in vicinity of the high voltage electrode. Most of previous works were based on manufacturers’ procedures and trial and error method to improve the surge arrester designs. In this work, optimisation of ZnO surge arrester design models using Gravitational Search Algorithm (GSA) and Imperialist Competitive Algorithm (ICA) is proposed. The surge arrester models were developed using finite element analysis (FEA) and used to determine the electric field distribution. The optimisation methods were used to determine the arrester design parameters which yield the minimum electric field stress surrounding the energized end of the surge arresters. GSA is less complex since it requires only two parameters to be adjusted i.e. mass and velocity while ICA demonstrates faster convergence and better achievement of global optimum. The performance of the proposed methods was then compared with the manufacturer’s test data and previously developed methods.

Design technique for leakage current reduction in surge arrester using gravitational search algorithm and imperialist competitive algorithm

2018 ◽  
Vol 37 (1) ◽  
pp. 357-374 ◽  
Author(s):  
Nurul Ain Abdul Latiff ◽  
Hazlee Azil Illias ◽  
Ab Halim Abu Bakar ◽  
Syahirah Abd Halim ◽  
Sameh Ziad Dabbak
Keyword(s):  
Leakage Current ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Imperialist Competitive Algorithm ◽  
Original Design ◽  
Element Analysis ◽  
Content Type ◽  
Competitive Algorithm ◽  
Surge Arresters ◽  
Gravitational Search

Purpose Leakage current is one of the factors, which can contribute towards degradation of surge arresters. Thus, the purpose of this paper is to study on leakage current within surge arresters and improvement on their design. Design/methodology/approach In this work, a three-dimensional model geometry of 11 kV zinc oxide surge arrester was designed in finite element analysis and was applied to calculate the leakage current under normal operating condition and being verified with measurement results. The optimisation methods were used to improve the arrester design by minimising the leakage current across the arrester using imperialist competitive algorithm (ICA) and gravitational search algorithm (GSA). Findings The arrester design in reducing leakage current was successfully optimised by varying the glass permittivity, silicone rubber permittivity and the width of the ground terminal of the surge arrester. It was found that the surge arrester design obtained using ICA has lower leakage current than GSA and the original design of the surge arrester. Practical implications The comparison between measurement and simulation enables factors that affect the mechanism of leakage current in surge arresters to be identified and provides the ideal design of arrester. Originality/value Surge arrester design was optimised by ICA and GSA, which has never been applied in past works in designing surge arrester with minimum leakage current.

Using Shear and DC Electric Fields to Manipulate and Self-Assemble Dielectric Particles on Microchannel Walls

2014 ◽  
Author(s):  
Minami Yoda ◽  
Necmettin Cevheri
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Poiseuille Flow ◽  
Lift Force ◽  
Colloidal Particles ◽  
Solid Surfaces ◽  
Electric Field Magnitude ◽  
Field Magnitude ◽  
Combined Flow ◽  
Lift Forces

Manipulating suspended neutrally buoyant colloidal particles of radii a = O(0.1 μm–1 μm) near solid surfaces, or walls, is a key technology in various microfluidics devices. These particles, suspended in an aqueous solution at rest near a solid surface, or wall, are subject to wall-normal “lift” forces described by the DLVO theory of colloid science. The particles experience additional lift forces, however, when suspended in a flowing solution. A fundamental understanding of such lift forces could therefore lead to new methods for the transport and self-assembly of particles near and on solid surfaces. Various studies have reported repulsive electroviscous and hydrodynamic lift forces on colloidal particles in Poiseuille flow (with a constant shear rate γ̇ near the wall) driven by a pressure gradient. A few studies have also observed repulsive dielectrophoretic-like lift forces in electroosmotic (EO) flows driven by electric fields. Recently, evanescent-wave particle tracking has been used to quantify near-wall lift forces on a = 125 nm–245 nm polystyrene (PS) particles suspended in a monovalent electrolyte solution in EO flow, Poiseuille flow, and combined Poiseuille and EO flow through ∼30 μm deep fused-silica channels. In Poiseuille flow, the repulsive lift force appears to be proportional to γ̇, a scaling consistent with hydrodynamic, vs. electroviscous, lift. In combined Poiseuille and EO flow, the lift forces can be repulsive or attractive, depending upon whether the EO flow is in the same or opposite direction as the Poiseuille flow, respectively. The magnitude of the force appears to be proportional to the electric field magnitude. Moreover, the force in combined flow exceeds the sum of the forces observed in EO flow for the same electric field or in Poiseuille flow for the same γ̇. Initial results also imply that this force, when repulsive, scales as γ̇1/2. These results suggest that the lift force in combined flow is fundamentally different from electroviscous, hydrodynamic, or dielectrophoretic-like lift. Moreover, for the case when the EO flow opposes the Poiseuille flow, the particles self-assemble into dense stable periodic streamwise bands with an average width of ∼6 μm and a spacing of 2–4 times the band width when the electric field magnitude exceeds a threshold value. These results are described and reviewed here.

Using Shear and Direct Current Electric Fields to Manipulate and Self-Assemble Dielectric Particles on Microchannel Walls

2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Necmettin Cevheri ◽  
Minami Yoda
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Poiseuille Flow ◽  
Lift Force ◽  
Colloidal Particles ◽  
Solid Surfaces ◽  
Electric Field Magnitude ◽  
Field Magnitude ◽  
Combined Flow ◽  
Lift Forces

Manipulating suspended neutrally buoyant colloidal particles of radii a = O (0.1–1 μm) near solid surfaces, or walls, is a key technology in various microfluidics devices. These particles, suspended in an aqueous solution at rest near a solid surface, or wall, are subject to wall-normal “lift” forces described by the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory of colloid science. The particles experience additional lift forces, however, when suspended in a flowing solution. A fundamental understanding of such lift forces could therefore lead to new methods for the transport and self-assembly of particles near and on solid surfaces. Various studies have reported repulsive electroviscous and hydrodynamic lift forces on colloidal particles in Poiseuille flow (with a constant shear rate γ· near the wall) driven by a pressure gradient. A few studies have also observed repulsive dielectrophoretic-like lift forces in electroosmotic (EO) flows driven by electric fields. Recently, evanescent-wave particle tracking has been used to quantify near-wall lift forces on a = 125–245 nm polystyrene (PS) particles suspended in a monovalent electrolyte solution in EO flow, Poiseuille flow, and combined Poiseuille and EO flow through ∼30 μm deep fused-silica channels. In Poiseuille flow, the repulsive lift force appears to be proportional to γ·, a scaling consistent with hydrodynamic, versus electroviscous, lift. In combined Poiseuille and EO flow, the lift forces can be repulsive or attractive, depending upon whether the EO flow is in the same or opposite direction as the Poiseuille flow, respectively. The magnitude of the force appears to be proportional to the electric field magnitude. Moreover, the force in combined flow exceeds the sum of the forces observed in EO flow for the same electric field and in Poiseuille flow for the same γ·. Initial results also imply that this force, when repulsive, scales as γ·1/2. These results suggest that the lift force in combined flow is fundamentally different from electroviscous, hydrodynamic, or dielectrophoretic-like lift. Moreover, for the case when the EO flow opposes the Poiseuille flow, the particles self-assemble into dense stable periodic streamwise bands with an average width of ∼6 μm and a spacing of 2–4 times the band width when the electric field magnitude exceeds a threshold value. These results are described and reviewed here.

A GSA-based adaptive fuzzy PID-controller for an active suspension system

2016 ◽  
Vol 33 (6) ◽  
pp. 1659-1667 ◽  
Author(s):  
Chun-Tang Chao ◽  
Ming-Tang Liu ◽  
Juing-Shian Chiou ◽  
Yi-Jung Huang ◽  
Chi-Jo Wang
Keyword(s):  
Pid Controller ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Suspension System ◽  
Fuzzy Pid ◽  
Content Type ◽  
Fuzzy Pid Controller ◽  
Fast Learning ◽  
Automobile Suspension ◽  
Hybrid Fuzzy Pid

Purpose – The purpose of this paper is to propose a novel design for determining the optimal hybrid fuzzy PID-controller of an active automobile suspension system, employing the gravitational search algorithm (GSA). Design/methodology/approach – The hybrid fuzzy PID-controller structure is an improvement to fuzzy PID-controller by incorporating a fast learning PID-controller. Findings – The GSA can adjust the parameters of the PID-controller to achieve the optimal performance. Research limitations/implications – The GSA may have the advantage of quick convergence, but the required computation may be intensive. Practical implications – The simulation results demonstrate the effectiveness of the proposed approach on active automobile suspension system. Originality/value – In order to demonstrate the theoretical guarantee of the proposed method, comparisons with particle swarm optimization or other methods has also been carried out.

Deformation of Nitrogen Bubbles in DC Electric Fields

2006 ◽  
Author(s):  
Feng Chen ◽  
Yao Peng ◽  
Yaozu Song ◽  
Min Chen
Keyword(s):  
Aspect Ratio ◽  
Electric Field ◽  
Electric Fields ◽  
Transformer Oil ◽  
Working Fluid ◽  
Direction Parallel ◽  
Electric Field Magnitude ◽  
Field Magnitude ◽  
Nitrogen Bubbles ◽  
Dc Electric Fields

The deformation of nitrogen bubbles in transformer oil with various DC electric fields was studied experimentally and theoretically. The bubble deformation was visualized by a high-speed digital camera. The major axis of the bubble was elongated along the direction parallel to the applied electric field, with the elongation increasing as the electric field magnitude increased. The electrical Weber number (We) was used to correlate the electric field magnitude and the electric permittivity of the working fluid to the bubble aspect ratio (AR). The experimental results indicate that the bubble aspect ratio increases with increasing We. The total electrical stresses were calculated on an actual bubble shape including the electrostriction stresses.

Time Dependent Polarization and Strain Evolution Around a Circular Hole in Ferroelectrics

2012 ◽  
Author(s):  
Q. D. Liu
Keyword(s):  
Electric Field ◽  
Circular Hole ◽  
Remnant Polarization ◽  
Strain Difference ◽  
Local Electric Field ◽  
Time Dependent ◽  
Principal Strain ◽  
Electric Field Effect ◽  
Electric Field Magnitude ◽  
Field Magnitude

The simulation of inhomogeneous creep around a circular hole in the center of ferroelectric plate is presented aiming for understanding the birefringence measurements around the hole. The time dependent fields of strain and polarization around the hole in response to its concentrated electric field effect can be determined using the finite element method. It was found that the electric field concentration factor by a hole can achieve 6 times of the applied loads and shows slightly time dependence; the creep of polarization and strains process is controlled by the local electric field magnitude, which governs the saturation of remnant polarization and strain. The result of geometric principal strain difference contours around the hole agrees with that of birefringence observation. The remnant polarization increased in a power-law relation with electric field magnitude, while the principal strain difference developed quadratically with the total electric displacement. Both experimental and numerical results suggest that the strain distributes around the hole and changes with time, which is controlled by both the local electric field magnitude and the saturation process. Although the inhomogeneities enhance fields locally, the saturated values of strain and polarization decrease with an increase in the defect volume.

Reduction of carbon emissions in VRP by gravitational search algorithm

2014 ◽  
Vol 25 (6) ◽  
pp. 766-782 ◽  
Author(s):  
S.A. MirHassani ◽  
S. Mohammadyari
Keyword(s):  
Air Pollution ◽  
Fuel Consumption ◽  
Carbon Emissions ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Influential Factors ◽  
Benchmark Problems ◽  
Minimum Length ◽  
Content Type ◽  
Gravitational Search

Purpose – Nowadays, global warming, due to large-scale emissions of greenhouse gasses, is among top environmental issues. The purpose of this paper is to present a problem involving the incorporation of environmental aspects into logistics, which provides a comparison between pollution reduction and distance-based approaches. Design/methodology/approach – In green vehicle routing problem (VRP), the aim is to model and solve an optimization problem in order to minimize the fuel consumption which results in reducing energy consumption as well as air pollution. The Gravitational Search Algorithm (GSA) is adapted and used as a powerful heuristic. Findings – Here, it is shown that a set of routes with minimum length is not an optimal solution for FCVRP model since the total distance is not the only effective factor for fuel consumption and vehicle's load plays an important role too. In many cases, a considerable reduction in emissions can be achieved by only an insignificant increase in costs. Research limitations/implications – Green transportation is a policy toward reducing carbon emissions. This research focussed on routes problem and introduce FCVRP model. GSA is used as a powerful heuristic to obtain high quality routes in a reasonable time. Considering other factors that affecting fuel consumption could make this study more realistic. Practical implications – When a distribution center receives all the information it needs about the demand from all the retail stores it supplies, a VRP is produced. So the models are valid for use by all goods producers and distributors. The preliminary assessment of the proposed model and method carried out on benchmark problems up to 200 nodes. Originality/value – Fuel consumption is one of the most influential factors in transportation costs. This paper introduces an innovative decision-making framework to obtain optimum routes in a vehicle routes problem considering air pollution. The results were compared from fuel consumption as well as total travel distance viewpoints.

Swarm-based chaotic gravitational search algorithm for solving mechanical engineering design problems

2020 ◽  
Vol 17 (1) ◽  
pp. 97-114
Author(s):  
Sajad Ahmad Rather ◽  
P. Shanthi Bala
Keyword(s):  
Engineering Design ◽  
Mechanical Engineering ◽  
Gravitational Constant ◽  
Chaotic Maps ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Experimental Results ◽  
Content Type ◽  
Efficient Performance ◽  
Gravitational Search

Purpose The purpose of this paper is to investigate the performance of chaotic gravitational search algorithm (CGSA) in solving mechanical engineering design frameworks including welded beam design (WBD), compression spring design (CSD) and pressure vessel design (PVD). Design/methodology/approach In this study, ten chaotic maps were combined with gravitational constant to increase the exploitation power of gravitational search algorithm (GSA). Also, CGSA has been used for maintaining the adaptive capability of gravitational constant. Furthermore, chaotic maps were used for overcoming premature convergence and stagnation in local minima problems of standard GSA. Findings The chaotic maps have shown efficient performance for WBD and PVD problems. Further, they have depicted competitive results for CSD framework. Moreover, the experimental results indicate that CGSA shows efficient performance in terms of convergence speed, cost function minimization, design variable optimization and successful constraint handling as compared to other participating algorithms. Research limitations/implications The use of chaotic maps in standard GSA is a new beginning for research in GSA particularly convergence and time complexity analysis. Moreover, CGSA can be used for solving the infinite impulsive response (IIR) parameter tuning and economic load dispatch problems in electrical sciences. Originality/value The hybridization of chaotic maps and evolutionary algorithms for solving practical engineering problems is an emerging topic in metaheuristics. In the literature, it can be seen that researchers have used some chaotic maps such as a logistic map, Gauss map and a sinusoidal map more rigorously than other maps. However, this work uses ten different chaotic maps for engineering design optimization. In addition, non-parametric statistical test, namely, Wilcoxon rank-sum test, was carried out at 5% significance level to statistically validate the simulation results. Besides, 11 state-of-the-art metaheuristic algorithms were used for comparative analysis of the experimental results to further raise the authenticity of the experimental setup.

A novel adaptive beamforming with reduced side lobe level using GSA

2018 ◽  
Vol 37 (6) ◽  
pp. 2263-2278 ◽  
Author(s):  
Abhinav Sharma ◽  
Sanjay Mathur
Keyword(s):  
Antenna Arrays ◽  
Search Algorithm ◽  
Fitness Function ◽  
Gravitational Search Algorithm ◽  
Side Lobe ◽  
Adaptive Beamforming ◽  
Side Lobe Level ◽  
Content Type ◽  
Multi Objective ◽  
Minimum Variance Distortionless Response

Purpose The purpose of this paper is to present and solve the problem of adaptive beamforming (ABF) for a uniform linear array (ULA) as an optimization problem. ABF mainly concerns with estimation of weights of antenna array so as to direct the major lobe in the direction of desired user and nulls in the direction of interfering signals with reduced side lobe level (SLL). Design/methodology/approach The potential of gravitational search algorithm is explored to optimize multi-objective fitness function for ABF using MATLAB software. Findings The performance of the algorithm has been compared by considering different number of interference signals at different power levels. The proposed algorithm presents good convergence rate and accurate steering of main lobe and nulls with reduced SLL compared to the well-known ABF technique, namely, minimum variance distortionless response (MVDR) and previously reported results. The simulation results are presented in tabular form. Research limitations/implications The present work is limited to simulation. The researchers are encouraged to solve the problem of ABF using the proposed approach in hardware. Originality/value The application of proposed algorithm is to optimize multi-objective function for ABF with reduced SLL in linear antenna arrays.

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