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Shape and electric performance improvement of an insulator string using particles swarm algorithm

IET SCIENCE MEASUREMENT & TECHNOLOGY 2020年第2期14卷 198-205页

作者： Doufene, Dyhia Bouazabia, Slimane Haddad, Abderrahmane Univ Sci & Technol Houari Boumediene Elect & Ind Syst Lab LSEI Bab Ezzouar Algeria Cardiff Univ Sch Engn Adv High Voltage Engn Res Ctr Cardiff CF24 3AA Wales

In this study, a particle swarm optimisation (PSO) algorithm coupled with finite-element method (FEM) is implemented to improve the performance of a cap-and-pin insulator by reducing the value of maximum electric field strength. Two goals are set in this work: (i) optimisation of the tangential electric field distribution and magnitude (which is taken as the objectif function to be minimised) to reduce the risk of flashover due to surface pollution, and (ii) reduction of the creepage distance (by adopting adequate constraints) leading to a reduction of the surface area and consequently a decrease in the insulator weight. The investigation is divided into two parts;first, one-unit insulator is optimised with which a chain is constructed, and its performance compared with the reference insulator string. The second part considers a whole chain of four-unit insulator whose performance is optimised and compared to that of a reference insulator string. The main finding of this work indicates that, if an insulator string is constructed using an optimised cap-and-pin unit, the performance of the so-formed string is also optimised. The optimisation of a complete string leads to practically the same performance as that of a string obtained by assembling optimised insulator units.

关键词： electric fields insulators finite element analysis flashover ceramic insulators particle swarm optimisation insulator contamination surface area insulator weight one-unit insulator four-unit insulator insulator string cap -pin unit complete string optimised insulator units electric performance improvement particles swarm algorithm particle swarm optimisation algorithm finite-element method -pin insulator maximum electric field strength tangential electric field distribution objectif function

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Environmental/economic dispatch incorporating renewable energy sources and plug-in vehicles

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IET GENERATION TRANSMISSION & DISTRIBUTION 2014年第12期8卷 2183-2198页

作者： Gholami, Amin Ansari, Javad Jamei, Mahdi Kazemi, Ahad Iran Univ Sci & Technol Sch Elect Engn Ctr Excellence Power Syst Automat & Operat Tehran Iran Florida Int Univ Elect & Comp Engn Dept Coll Engn & Comp Miami FL 33199 USA

Transportation and electricity industries are considered as major sources of greenhouse gases (GHGs) emission. Different methods have been proposed to deal with the increasing rate of the emission, such as employing plug-in electric vehicles (PEVs) and integrating renewable energy sources (RESs). However, it is important to scrutinise different scenarios of incorporating the mentioned elements to decrease the concerning emission rate while considering the economic constraints. In this study, a combined economic emission dispatch (CEED) is employed to investigate the effectiveness of using PEVs and RESs from different aspects. A sensitivity analysis is executed to survey the influence of emission and cost coefficients. Two test cases each including different scenarios are simulated to determine the efficacy of different types of integration in the proposed model. To have a more accurate and realistic survey, an extended model of the wind farm's cost function is employed in economic dispatch calculations. The particle swarm optimisation algorithm is applied to solve the CEED non-linear problem. The obtained results indicate that the integration of PEVs cannot necessarily reduce the net emission of two industries. In fact, the optimum solution should include the incorporation of PEVs along with RESs to return the desired results.

关键词： electric vehicles renewable energy sources air pollution control wind power plants power generation dispatch power generation economics particle swarm optimisation nonlinear programming renewable energy source transportation electricity industry greenhouse gas emission GHG emission PEV plug-in electric vehicle RES combined economic emission dispatch CEED environmental-economic dispatch sensitivity analysis wind farm particle swarm optimisation algorithm nonlinear problem

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Protection coordination of directional overcurrent relays: new time current characteristic and objective function

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IET GENERATION TRANSMISSION & DISTRIBUTION 2018年第1期12卷 190-199页

作者： Yazdaninejadi, Amin Naderi, Mehdi S. Gharehpetian, Gevork B. Talavat, Vahid Urmia Univ Elect Engn Dept Orumiyeh Iran Amirkabir Univ IGSORC Tehran Iran Amirkabir Univ Elect Engn Dept Tehran Iran

Clearing power grid faults swiftly and selectively offers higher security, reliability and sustainability. Accomplishing this aim by deploying directional overcurrent relays (DOCRs) is one of the major challenges in meshed and multisource distribution networks. To overcome this challenge, the current study elaborates a new coordination strategy which concentrates on minimising overall operation time of relays. In this strategy, an auxiliary variable is added to classical operation time model of each DOCR. All the auxiliary variables are considered as coordination constraints which help to yield new and well-defined time current characteristics (TCCs). In other words, more flexibility is attained in adjusting relay's characteristic which helps to alleviate clearing time of faults. The obtained TCCs can be easily performed by numerical relays. In addition, a new objective function is defined to steer the relay settings towards optimal solutions conveniently. It was shown that the proposed approach not only reduces the operation time of relays, but also prevents miscoordinations. This approach demonstrates a non-linear programming model tackled by particle swarm optimisation algorithm. The effectiveness of the proposed approach is verified via 8-bus and IEEE 14-bus test systems and results are discussed in depth.

关键词： relay protection overcurrent protection power grids fault diagnosis power distribution protection nonlinear programming numerical analysis protection coordination directional overcurrent relays DOCR time current characteristic objective function power grid faults meshed distribution networks multisource distribution networks classical operation time model auxiliary variables coordination constraints TCC numerical relays operation time nonlinear programming model particle swarm optimisation algorithm 8-bus test systems IEEE 14-bus test systems

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Optimal sizing of a grid integrated solar photovoltaic system

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IET RENEWABLE POWER GENERATION 2014年第1期8卷 67-75页

作者： Khare, Anula Rangnekar, Saroj Maulana Azad Natl Inst Technol Dept Energy Bhopal 462051 India

This study proposes an optimal sizing methodology for a solar photovoltaic (SPV) system considering lifetime cost requirements. The aim of the design is optimal sizing of SPV system, which is obtained by calculating SPV system output power at certain location, taking into account the calculated optimal number of SPV modules, optimal number of inverters, optimal tilt angle, for a given dimension of land. This design is aimed for minimising the annual cost of grid-integrated SPV system over its life or years of operation. The cost function takes into account the capital cost of installation, operation and maintenance, for each component of the system and the cost of selling energy to the grid. The sizing optimisation has been formulated as a non-linear, multi-variable problem and the particle swarm optimisation algorithm has been tested using MATLAB platform for a particular location to swot up the feasibility of integrated system. The monthly averaged daily and hourly solar radiation data for a given location is calculated using empirical relations on MATLAB platform. Other inputs are specifications of commercially available devices and meteorological details of location.

关键词： maintenance engineering particle swarm optimisation photovoltaic power systems power grids empirical relations MATLAB platform particle swarm optimisation algorithm multivariable problem nonlinear problem sizing optimisation maintenance cost function grid-integrated SPV system optimal sizing SPV system solar photovoltaic system optimal sizing methodology grid integrated solar photovoltaic system

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A DBN-PSOSA hybrid response surface method for bridge reliability

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EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING 2022年第14期26卷 7226-7239页

作者： Lu, Pengzhen Hong, Tao Xu, Zijie Wu, Ying Li, Dengguo Zhejiang Univ Technol Coll Civil Engn Hangzhou Zhejiang Peoples R China Jiaxing Nanhu Univ Jiaxing Zhejiang Peoples R China

When solving bridge reliability problems, the traditional response surface method has a highly nonlinear implicit function, which results in a low fitting accuracy and difficulty in meeting the requirements. Therefore, the dynamic Bayesian network (DBN), which is suitable for solving a multi-state unit or system uncertainty problems, is selected to construct the response surface of the implicit function. In this study, the DBN model is combined with the particle swarm optimisation based on simulated annealing (PSOSA) algorithm to improve the optimisation efficiency of model parameters and allow the constructed implicit function to simulate the structure limit state function. The DBN-PSOSA hybrid response surface analysis method is proposed for bridge failure probability calculations. A numerical example is given to demonstrate the effectiveness of the proposed method, and the reliability of an actual bridge project is analysed. The results indicate that this method has a higher calculation accuracy and efficiency compared to the traditional response surface method, and is easy to combine with the existing general finite element analysis software to achieve the rapid analysis of bridge structure reliability.

关键词： Bridge engineering reliability analysis dynamic Bayesian networks particle swarm optimisation algorithm annealing algorithm

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Structural evolution and ligand effects of (Au1L2)n, (Au2L3)n, and (Au3L4)n [n =1-3, L = SCH3,P(CH3)2,PH2,Cl] clusters

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MOLECULAR SIMULATION 2020年第1期46卷 1-8页

作者： Ma, Miaomiao Liu, Liren Zhu, Hengjiang Lu, Junzhe Tan, Guiping Xinjiang Normal Univ Coll Phys & Elect Engn Urumqi Peoples R China Key Lab Mineral Luminescence Mat & Micro Struct X Urumqi Peoples R China

In this paper, we present a density-functional theory with a particle swarm optimisation algorithm to research the progress of the ligand effects of the gold (Au) structures and growth process of the [Au1L2](n), [Au2L3](n) and [Au3L4](n) (n = 1-3, L = SCH3, PH2, P(CH3)(2),Cl) nanoclusters. Changing of ligand atoms induces minor changes in the Au and Au-L bond lengths. When L = Cl, with increasing n, the size of the Au cores tends to increase, while when L = PH2, with increasing n, the size of Au cores decreases and the length of the ligand protection increases. We give a detailed comparison of the average binding energy, stability, and aromaticity of these clusters and further explain the diverse role of ligand substitution. The order of stability for each ligand, Cl > PH2> SCH3>P(CH3)(2), is determined by the average binding energy and the difference between the atomic energies. In addition, the influence of strong Au-Au interactions will weaken the aromaticity of the structure. New nanoclusters that can be widely applied in other fields, and designed by leveraging the ligand effects of the Au structural evolution characteristics.

关键词： Density-functional theory particle swarm optimisation algorithm ligand effects structural evolution

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Coherent unambiguous transmit for sparse linear array with geography constraint

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IET RADAR SONAR AND NAVIGATION 2017年第2期11卷 386-393页

作者： Yu, Xianxiang Cui, Guolong Yang, Shiqian Kong, Lingjiang Yi, Wei Univ Elect Sci & Technol China Sch Elect Engn Chengdu 611731 Sichuan Peoples R China

This study considers the sparse linear array (SLA) design problem of coherent unambiguous transmit for the distributed aperture coherence-synthetic radar, accounting for the antenna size constraint and geography constraint where the elements cannot be placed in a given region. The authors develop an objective function considering the sum of the peak sidelobe level (PSL) for different beam shifting directions. Then, based on a processing strategy for considered constraints, they derive the antenna element locations by minimising the objective function through particle swarm optimisation algorithm. Finally, several numerical simulations verify the effectiveness of the proposed SLA design method.

关键词： synthetic aperture radar radar antennas linear antenna arrays particle swarm optimisation numerical analysis coherent unambiguous transmit sparse linear array design problem geography constraint SLA design problem distributed aperture coherence-synthetic radar antenna size constraint objective function minimisation beam shifting directions processing strategy antenna element locations particle swarm optimisation algorithm numerical simulations

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Sidelobe-level suppression for linear and circular antenna arrays via the cuckoo search-chicken swarm optimisation algorithm

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IET MICROWAVES ANTENNAS & PROPAGATION 2017年第2期11卷 209-218页

作者： Liang, Shuang Feng, Tie Sun, Geng Jilin Univ Coll Software Changchun 130012 Jilin Peoples R China Jilin Univ Coll Comp Sci & Technol Changchun 130012 Jilin Peoples R China Jilin Univ Key Lab Symbol Computat & Knowledge Engn Minist Educ Changchun 130012 Jilin Peoples R China

An antenna array application with high directivity and low sidelobe level (SLL) is an important technology that can enhance the reliability and validity of a communication system. In recent years, swarm intelligence optimisation algorithms have been widely used in the design of antenna arrays. In this study, a hybrid heuristic swarm intelligence optimisation algorithm called cuckoo search-chicken swarm optimisation (CSCSO) is proposed to optimise the excitation amplitude of a linear antenna array (LAA) and the excitation amplitude and spacing between the array elements of a circular antenna array (CAA). The maximum SLL will be obtained while the mainlobe width is fixed. CSCSO combines cuckoo search (CS) and chicken swarm optimisation (CSO) and thus, it will have the excellent global search capability of CS as well as introduce the hierarchy mechanism of CSO to improve algorithm precision. Chaos theory is utilised to determine the initial solution of the algorithm, while Levy flight weight coefficient is used to improve the convergence rate in CSCSO. Simulation results show that CSCSO has a better performance in terms of solution accuracy and convergence rate in the radiation pattern optimisation of LAA and CAA compared with the standard CSO, CS, and particle swarm optimisation algorithms.

关键词： linear antenna arrays search problems antenna radiation patterns optimisation sidelobe-level suppression cuckoo search-chicken swarm optimisation algorithm SLL suppression reliability communication system CSCSO LAA CAA linear antenna array circular antenna array chaos theory Levy flight weight coefficient radiation pattern optimisation particle swarm optimisation algorithm

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Robust scheme for voltage regulation and power sharing among DERs in DC microgrids

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IET RENEWABLE POWER GENERATION 2020年第4期14卷 647-657页

作者： Malek, Sajjad Gholipour, Mehdi Univ Isfahan Dept Elect Engn Esfahan Iran

This study presents a new control scheme to provide both voltage regulation and power sharing within a DC microgrid. It includes both primary and secondary levels as well as the proposed auxiliary feedback. The secondary control distributes and uses the consensus algorithm to share power. First, the auxiliary feedback is formulated. Then the features of the feedback are analytically extracted to provide both voltage regulation and power sharing. Next, the particle swarm optimisation algorithm determines the parameters of the controller optimally. Following that, a series of simulations is carried out to show the performance of the proposed scheme in comparison with the conventional methods. Hence, to validate the advantages of the proposed scheme, a four distributed energy resource (DER) DC microgrid is considered, and the proposed approach is applied. Afterwards, the eigenvalue and sensitivity analysis show the effect of the parameters variation on microgrid stability. The results show that the applied method can regulate the voltage well and shares the power in the presence of the load demand as a disturbance besides the long-time delay associated with the secondary control as an uncertainty.

关键词： eigenvalues and eigenfunctions distributed power generation sensitivity analysis feedback voltage control particle swarm optimisation robust control optimal control power system stability power system control secondary control voltage regulation particle swarm optimisation algorithm distributed energy resource DC microgrid microgrid stability robust scheme power sharing optimal control eigenvalue sensitivity analysis

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Performance analysis of cooperative PDMA with AF relaying over Rayleigh fading channels

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IET COMMUNICATIONS 2020年第13期14卷 2166-2175页

作者： Zhang, Xiurong Kang, Shaoli Fu, Xueqian Tang, Wanwei Beihang Univ Sch Elect & Informat Engn Beijing 100191 Peoples R China China Acad Telecommun Technol State Key Lab Wireless Mobile Commun Beijing 100191 Peoples R China China Agr Univ Coll Informat & Elect Engn Beijing 100083 Peoples R China Tangshan Univ Intelligence & Informat Engn Coll Tangshan 063000 Peoples R China

This study investigates the performances of cooperative pattern division multiple access (PDMA) technology with a half-duplex amplify-and-forward (AF) relaying over Rayleigh fading channels. To characterise the performances of the AF-PDMA system, the closed-form expressions of the exact outage probabilities, system throughput and diversity order are derived, respectively. The particle swarm optimisation algorithm based on penalty function is used to obtain the optimum power allocation coefficients by maximising the system throughput. By setting different values on the target data rate for users to analyse the AF-PDMA system throughput performance, simulation results demonstrate the performance enhancement of the considered AF-PDMA compared with orthogonal multiple access with AF relaying and PDMA with decode-and-forward relaying.

关键词： amplify and forward communication Rayleigh channels fading channels probability particle swarm optimisation performance analysis Rayleigh fading channels pattern division multiple access half-duplex amplify-and-forward AF-PDMA system closed-form expressions exact outage probabilities system throughput particle swarm optimisation algorithm optimum power allocation coefficients performance enhancement considered AF-PDMA orthogonal multiple access

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