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Publisher: Emerald   (Total: 341 journals)

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Showing 1 - 200 of 341 Journals sorted alphabetically
A Life in the Day     Hybrid Journal   (Followers: 12)
Academia Revista Latinoamericana de Administración     Open Access   (Followers: 2, SJR: 0.178, CiteScore: 1)
Accounting Auditing & Accountability J.     Hybrid Journal   (Followers: 30, SJR: 1.71, CiteScore: 3)
Accounting Research J.     Hybrid Journal   (Followers: 25, SJR: 0.144, CiteScore: 0)
Accounting, Auditing and Accountability J.     Hybrid Journal   (Followers: 21, SJR: 2.187, CiteScore: 4)
Advances in Accounting Education     Hybrid Journal   (Followers: 16, SJR: 0.279, CiteScore: 0)
Advances in Appreciative Inquiry     Hybrid Journal   (Followers: 1, SJR: 0.451, CiteScore: 1)
Advances in Autism     Hybrid Journal   (Followers: 21, SJR: 0.222, CiteScore: 1)
Advances in Dual Diagnosis     Hybrid Journal   (Followers: 46, SJR: 0.21, CiteScore: 1)
Advances in Gender Research     Full-text available via subscription   (Followers: 4, SJR: 0.16, CiteScore: 0)
Advances in Intl. Marketing     Full-text available via subscription   (Followers: 6)
Advances in Mental Health and Intellectual Disabilities     Hybrid Journal   (Followers: 72, SJR: 0.296, CiteScore: 0)
Advances in Mental Health and Learning Disabilities     Hybrid Journal   (Followers: 30)
African J. of Economic and Management Studies     Hybrid Journal   (Followers: 10, SJR: 0.216, CiteScore: 1)
Agricultural Finance Review     Hybrid Journal   (SJR: 0.406, CiteScore: 1)
Aircraft Engineering and Aerospace Technology     Hybrid Journal   (Followers: 198, SJR: 0.354, CiteScore: 1)
American J. of Business     Hybrid Journal   (Followers: 17)
Annals in Social Responsibility     Full-text available via subscription  
Anti-Corrosion Methods and Materials     Hybrid Journal   (Followers: 11, SJR: 0.235, CiteScore: 1)
Arts and the Market     Hybrid Journal   (Followers: 9)
Asia Pacific J. of Innovation and Entrepreneurship     Open Access  
Asia Pacific J. of Marketing and Logistics     Hybrid Journal   (Followers: 8, SJR: 0.425, CiteScore: 1)
Asia-Pacific J. of Business Administration     Hybrid Journal   (Followers: 5, SJR: 0.234, CiteScore: 1)
Asian Association of Open Universities J.     Open Access   (Followers: 1)
Asian Education and Development Studies     Hybrid Journal   (Followers: 5, SJR: 0.233, CiteScore: 1)
Asian J. on Quality     Hybrid Journal   (Followers: 3)
Asian Review of Accounting     Hybrid Journal   (Followers: 2, SJR: 0.222, CiteScore: 1)
Aslib J. of Information Management     Hybrid Journal   (Followers: 27, SJR: 0.725, CiteScore: 2)
Aslib Proceedings     Hybrid Journal   (Followers: 298)
Assembly Automation     Hybrid Journal   (Followers: 2, SJR: 0.603, CiteScore: 2)
Baltic J. of Management     Hybrid Journal   (Followers: 3, SJR: 0.309, CiteScore: 1)
Benchmarking : An Intl. J.     Hybrid Journal   (Followers: 10, SJR: 0.559, CiteScore: 2)
British Food J.     Hybrid Journal   (Followers: 16, SJR: 0.5, CiteScore: 2)
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 14, SJR: 0.46, CiteScore: 1)
Business Process Re-engineering & Management J.     Hybrid Journal   (Followers: 8)
Business Strategy Series     Hybrid Journal   (Followers: 6)
Career Development Intl.     Hybrid Journal   (Followers: 17, SJR: 0.527, CiteScore: 2)
China Agricultural Economic Review     Hybrid Journal   (Followers: 2, SJR: 0.31, CiteScore: 1)
China Finance Review Intl.     Hybrid Journal   (Followers: 5, SJR: 0.245, CiteScore: 0)
Chinese Management Studies     Hybrid Journal   (Followers: 4, SJR: 0.278, CiteScore: 1)
Circuit World     Hybrid Journal   (Followers: 15, SJR: 0.246, CiteScore: 1)
Collection Building     Hybrid Journal   (Followers: 11, SJR: 0.296, CiteScore: 1)
COMPEL: The Intl. J. for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3, SJR: 0.22, CiteScore: 1)
Competitiveness Review : An Intl. Business J. incorporating J. of Global Competitiveness     Hybrid Journal   (Followers: 5, SJR: 0.274, CiteScore: 1)
Construction Innovation: Information, Process, Management     Hybrid Journal   (Followers: 14, SJR: 0.731, CiteScore: 2)
Corporate Communications An Intl. J.     Hybrid Journal   (Followers: 7, SJR: 0.453, CiteScore: 1)
Corporate Governance Intl. J. of Business in Society     Hybrid Journal   (Followers: 7, SJR: 0.336, CiteScore: 1)
Critical Perspectives on Intl. Business     Hybrid Journal   (SJR: 0.378, CiteScore: 1)
Cross Cultural & Strategic Management     Hybrid Journal   (Followers: 8, SJR: 0.504, CiteScore: 2)
Development and Learning in Organizations     Hybrid Journal   (Followers: 7, SJR: 0.138, CiteScore: 0)
Digital Library Perspectives     Hybrid Journal   (Followers: 24, SJR: 0.341, CiteScore: 1)
Direct Marketing An Intl. J.     Hybrid Journal   (Followers: 6)
Disaster Prevention and Management     Hybrid Journal   (Followers: 21, SJR: 0.47, CiteScore: 1)
Drugs and Alcohol Today     Hybrid Journal   (Followers: 133, SJR: 0.245, CiteScore: 1)
Education + Training     Hybrid Journal   (Followers: 23)
Education, Business and Society : Contemporary Middle Eastern Issues     Hybrid Journal   (Followers: 1, SJR: 1.707, CiteScore: 3)
Emerald Emerging Markets Case Studies     Hybrid Journal   (Followers: 1)
Employee Relations     Hybrid Journal   (Followers: 8, SJR: 0.551, CiteScore: 2)
Engineering Computations     Hybrid Journal   (Followers: 3, SJR: 0.444, CiteScore: 1)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 10, SJR: 0.653, CiteScore: 2)
English Teaching: Practice & Critique     Hybrid Journal   (SJR: 0.417, CiteScore: 1)
Equal Opportunities Intl.     Hybrid Journal   (Followers: 3)
Equality, Diversity and Inclusion : An Intl. J.     Hybrid Journal   (Followers: 13, SJR: 0.5, CiteScore: 1)
EuroMed J. of Business     Hybrid Journal   (Followers: 1, SJR: 0.26, CiteScore: 1)
European Business Review     Hybrid Journal   (Followers: 8, SJR: 0.585, CiteScore: 3)
European J. of Innovation Management     Hybrid Journal   (Followers: 23, SJR: 0.454, CiteScore: 2)
European J. of Management and Business Economics     Open Access   (Followers: 1, SJR: 0.239, CiteScore: 1)
European J. of Marketing     Hybrid Journal   (Followers: 20, SJR: 0.971, CiteScore: 2)
European J. of Training and Development     Hybrid Journal   (Followers: 11, SJR: 0.477, CiteScore: 1)
Evidence-based HRM     Hybrid Journal   (Followers: 5, SJR: 0.537, CiteScore: 1)
Facilities     Hybrid Journal   (Followers: 2, SJR: 0.503, CiteScore: 2)
Foresight     Hybrid Journal   (Followers: 7, SJR: 0.34, CiteScore: 1)
Gender in Management : An Intl. J.     Hybrid Journal   (Followers: 18, SJR: 0.412, CiteScore: 1)
Grey Systems : Theory and Application     Hybrid Journal   (Followers: 1)
Health Education     Hybrid Journal   (Followers: 2, SJR: 0.421, CiteScore: 1)
Higher Education, Skills and Work-based Learning     Hybrid Journal   (Followers: 46, SJR: 0.426, CiteScore: 1)
History of Education Review     Hybrid Journal   (Followers: 12, SJR: 0.26, CiteScore: 0)
Housing, Care and Support     Hybrid Journal   (Followers: 8, SJR: 0.171, CiteScore: 0)
Human Resource Management Intl. Digest     Hybrid Journal   (Followers: 17, SJR: 0.129, CiteScore: 0)
Humanomics     Hybrid Journal   (Followers: 2, SJR: 0.333, CiteScore: 1)
IMP J.     Hybrid Journal  
Indian Growth and Development Review     Hybrid Journal   (SJR: 0.174, CiteScore: 0)
Industrial and Commercial Training     Hybrid Journal   (Followers: 5, SJR: 0.301, CiteScore: 1)
Industrial Lubrication and Tribology     Hybrid Journal   (Followers: 5, SJR: 0.334, CiteScore: 1)
Industrial Management & Data Systems     Hybrid Journal   (Followers: 7, SJR: 0.904, CiteScore: 3)
Industrial Robot An Intl. J.     Hybrid Journal   (Followers: 2, SJR: 0.318, CiteScore: 1)
Info     Hybrid Journal   (Followers: 1)
Information and Computer Security     Hybrid Journal   (Followers: 22, SJR: 0.307, CiteScore: 1)
Information Technology & People     Hybrid Journal   (Followers: 43, SJR: 0.671, CiteScore: 2)
Interactive Technology and Smart Education     Hybrid Journal   (Followers: 11, SJR: 0.191, CiteScore: 1)
Interlending & Document Supply     Hybrid Journal   (Followers: 60)
Internet Research     Hybrid Journal   (Followers: 37, SJR: 1.645, CiteScore: 5)
Intl. J. for Lesson and Learning Studies     Hybrid Journal   (Followers: 4, SJR: 0.324, CiteScore: 1)
Intl. J. for Researcher Development     Hybrid Journal   (Followers: 10)
Intl. J. of Accounting and Information Management     Hybrid Journal   (Followers: 9, SJR: 0.275, CiteScore: 1)
Intl. J. of Bank Marketing     Hybrid Journal   (Followers: 8, SJR: 0.654, CiteScore: 3)
Intl. J. of Climate Change Strategies and Management     Hybrid Journal   (Followers: 16, SJR: 0.353, CiteScore: 1)
Intl. J. of Clothing Science and Technology     Hybrid Journal   (Followers: 7, SJR: 0.318, CiteScore: 1)
Intl. J. of Commerce and Management     Hybrid Journal   (Followers: 1)
Intl. J. of Conflict Management     Hybrid Journal   (Followers: 15, SJR: 0.362, CiteScore: 1)
Intl. J. of Contemporary Hospitality Management     Hybrid Journal   (Followers: 13, SJR: 1.452, CiteScore: 4)
Intl. J. of Culture Tourism and Hospitality Research     Hybrid Journal   (Followers: 19, SJR: 0.339, CiteScore: 1)
Intl. J. of Development Issues     Hybrid Journal   (Followers: 9, SJR: 0.139, CiteScore: 0)
Intl. J. of Disaster Resilience in the Built Environment     Hybrid Journal   (Followers: 6, SJR: 0.387, CiteScore: 1)
Intl. J. of Educational Management     Hybrid Journal   (Followers: 5, SJR: 0.559, CiteScore: 1)
Intl. J. of Emergency Services     Hybrid Journal   (Followers: 6, SJR: 0.201, CiteScore: 1)
Intl. J. of Emerging Markets     Hybrid Journal   (Followers: 3, SJR: 0.474, CiteScore: 2)
Intl. J. of Energy Sector Management     Hybrid Journal   (Followers: 2, SJR: 0.349, CiteScore: 1)
Intl. J. of Entrepreneurial Behaviour & Research     Hybrid Journal   (Followers: 4, SJR: 0.629, CiteScore: 2)
Intl. J. of Event and Festival Management     Hybrid Journal   (Followers: 5, SJR: 0.388, CiteScore: 1)
Intl. J. of Gender and Entrepreneurship     Hybrid Journal   (Followers: 6, SJR: 0.445, CiteScore: 1)
Intl. J. of Health Care Quality Assurance     Hybrid Journal   (Followers: 12, SJR: 0.358, CiteScore: 1)
Intl. J. of Health Governance     Hybrid Journal   (Followers: 26, SJR: 0.247, CiteScore: 1)
Intl. J. of Housing Markets and Analysis     Hybrid Journal   (Followers: 9, SJR: 0.211, CiteScore: 1)
Intl. J. of Human Rights in Healthcare     Hybrid Journal   (Followers: 7, SJR: 0.205, CiteScore: 0)
Intl. J. of Information and Learning Technology     Hybrid Journal   (Followers: 8, SJR: 0.226, CiteScore: 1)
Intl. J. of Innovation Science     Hybrid Journal   (Followers: 11, SJR: 0.197, CiteScore: 1)
Intl. J. of Intelligent Computing and Cybernetics     Hybrid Journal   (Followers: 3, SJR: 0.214, CiteScore: 1)
Intl. J. of Intelligent Unmanned Systems     Hybrid Journal   (Followers: 4)
Intl. J. of Islamic and Middle Eastern Finance and Management     Hybrid Journal   (Followers: 9, SJR: 0.375, CiteScore: 1)
Intl. J. of Law and Management     Hybrid Journal   (Followers: 2, SJR: 0.217, CiteScore: 1)
Intl. J. of Law in the Built Environment     Hybrid Journal   (Followers: 3, SJR: 0.227, CiteScore: 0)
Intl. J. of Leadership in Public Services     Hybrid Journal   (Followers: 20)
Intl. J. of Lean Six Sigma     Hybrid Journal   (Followers: 6, SJR: 0.802, CiteScore: 3)
Intl. J. of Logistics Management     Hybrid Journal   (Followers: 10, SJR: 0.71, CiteScore: 2)
Intl. J. of Managerial Finance     Hybrid Journal   (Followers: 5, SJR: 0.203, CiteScore: 1)
Intl. J. of Managing Projects in Business     Hybrid Journal   (Followers: 2, SJR: 0.36, CiteScore: 2)
Intl. J. of Manpower     Hybrid Journal   (Followers: 2, SJR: 0.365, CiteScore: 1)
Intl. J. of Mentoring and Coaching in Education     Hybrid Journal   (Followers: 24, SJR: 0.426, CiteScore: 1)
Intl. J. of Migration, Health and Social Care     Hybrid Journal   (Followers: 12, SJR: 0.307, CiteScore: 1)
Intl. J. of Numerical Methods for Heat & Fluid Flow     Hybrid Journal   (Followers: 11, SJR: 0.697, CiteScore: 3)
Intl. J. of Operations & Production Management     Hybrid Journal   (Followers: 18, SJR: 2.052, CiteScore: 4)
Intl. J. of Organizational Analysis     Hybrid Journal   (Followers: 3, SJR: 0.268, CiteScore: 1)
Intl. J. of Pervasive Computing and Communications     Hybrid Journal   (Followers: 3, SJR: 0.138, CiteScore: 1)
Intl. J. of Pharmaceutical and Healthcare Marketing     Hybrid Journal   (Followers: 4, SJR: 0.25, CiteScore: 1)
Intl. J. of Physical Distribution & Logistics Management     Hybrid Journal   (Followers: 11, SJR: 1.821, CiteScore: 4)
Intl. J. of Prisoner Health     Hybrid Journal   (Followers: 8, SJR: 0.303, CiteScore: 1)
Intl. J. of Productivity and Performance Management     Hybrid Journal   (Followers: 7, SJR: 0.578, CiteScore: 2)
Intl. J. of Public Sector Management     Hybrid Journal   (Followers: 25, SJR: 0.438, CiteScore: 1)
Intl. J. of Quality & Reliability Management     Hybrid Journal   (Followers: 7, SJR: 0.492, CiteScore: 2)
Intl. J. of Quality and Service Sciences     Hybrid Journal   (Followers: 2, SJR: 0.309, CiteScore: 1)
Intl. J. of Retail & Distribution Management     Hybrid Journal   (Followers: 6, SJR: 0.742, CiteScore: 3)
Intl. J. of Service Industry Management     Hybrid Journal   (Followers: 2)
Intl. J. of Social Economics     Hybrid Journal   (Followers: 5, SJR: 0.225, CiteScore: 1)
Intl. J. of Sociology and Social Policy     Hybrid Journal   (Followers: 49, SJR: 0.3, CiteScore: 1)
Intl. J. of Sports Marketing and Sponsorship     Hybrid Journal   (Followers: 1, SJR: 0.269, CiteScore: 1)
Intl. J. of Structural Integrity     Hybrid Journal   (Followers: 2, SJR: 0.228, CiteScore: 0)
Intl. J. of Sustainability in Higher Education     Hybrid Journal   (Followers: 14, SJR: 0.502, CiteScore: 2)
Intl. J. of Tourism Cities     Hybrid Journal   (Followers: 2, SJR: 0.502, CiteScore: 0)
Intl. J. of Web Information Systems     Hybrid Journal   (Followers: 4, SJR: 0.186, CiteScore: 1)
Intl. J. of Wine Business Research     Hybrid Journal   (Followers: 8, SJR: 0.562, CiteScore: 2)
Intl. J. of Workplace Health Management     Hybrid Journal   (Followers: 11, SJR: 0.303, CiteScore: 1)
Intl. Marketing Review     Hybrid Journal   (Followers: 15, SJR: 0.895, CiteScore: 3)
Irish J. of Occupational Therapy     Open Access   (Followers: 1)
ISRA Intl. J. of Islamic Finance     Open Access  
J. for Multicultural Education     Hybrid Journal   (Followers: 1, SJR: 0.237, CiteScore: 1)
J. of Accounting & Organizational Change     Hybrid Journal   (Followers: 5, SJR: 0.301, CiteScore: 1)
J. of Accounting in Emerging Economies     Hybrid Journal   (Followers: 9)
J. of Adult Protection, The     Hybrid Journal   (Followers: 15, SJR: 0.314, CiteScore: 1)
J. of Advances in Management Research     Hybrid Journal   (Followers: 2)
J. of Aggression, Conflict and Peace Research     Hybrid Journal   (Followers: 44, SJR: 0.222, CiteScore: 1)
J. of Agribusiness in Developing and Emerging Economies     Hybrid Journal   (SJR: 0.108, CiteScore: 0)
J. of Applied Accounting Research     Hybrid Journal   (Followers: 16, SJR: 0.227, CiteScore: 1)
J. of Applied Research in Higher Education     Hybrid Journal   (Followers: 49, SJR: 0.2, CiteScore: 0)
J. of Asia Business Studies     Hybrid Journal   (Followers: 2, SJR: 0.245, CiteScore: 1)
J. of Assistive Technologies     Hybrid Journal   (Followers: 20)
J. of Business & Industrial Marketing     Hybrid Journal   (Followers: 8, SJR: 0.652, CiteScore: 2)
J. of Business Strategy     Hybrid Journal   (Followers: 11, SJR: 0.333, CiteScore: 1)
J. of Centrum Cathedra     Open Access  
J. of Children's Services     Hybrid Journal   (Followers: 5, SJR: 0.243, CiteScore: 1)
J. of Chinese Economic and Foreign Trade Studies     Hybrid Journal   (Followers: 1, SJR: 0.2, CiteScore: 0)
J. of Chinese Entrepreneurship     Hybrid Journal   (Followers: 4)
J. of Chinese Human Resource Management     Hybrid Journal   (Followers: 6, SJR: 0.173, CiteScore: 1)
J. of Communication Management     Hybrid Journal   (Followers: 6, SJR: 0.625, CiteScore: 1)
J. of Consumer Marketing     Hybrid Journal   (Followers: 17, SJR: 0.664, CiteScore: 2)
J. of Corporate Real Estate     Hybrid Journal   (Followers: 3, SJR: 0.368, CiteScore: 1)
J. of Criminal Psychology     Hybrid Journal   (Followers: 125, SJR: 0.268, CiteScore: 1)
J. of Criminological Research, Policy and Practice     Hybrid Journal   (Followers: 46, SJR: 0.254, CiteScore: 1)
J. of Cultural Heritage Management and Sustainable Development     Hybrid Journal   (Followers: 10, SJR: 0.257, CiteScore: 1)
J. of Documentation     Hybrid Journal   (Followers: 177, SJR: 0.613, CiteScore: 1)
J. of Economic and Administrative Sciences     Hybrid Journal   (Followers: 2)
J. of Economic Studies     Hybrid Journal   (Followers: 5, SJR: 0.733, CiteScore: 1)
J. of Educational Administration     Hybrid Journal   (Followers: 6, SJR: 1.252, CiteScore: 2)
J. of Enabling Technologies     Hybrid Journal   (Followers: 8, SJR: 0.369, CiteScore: 1)
J. of Engineering, Design and Technology     Hybrid Journal   (Followers: 16, SJR: 0.212, CiteScore: 1)
J. of Enterprise Information Management     Hybrid Journal   (Followers: 4, SJR: 0.827, CiteScore: 4)
J. of Enterprising Communities People and Places in the Global Economy     Hybrid Journal   (Followers: 1, SJR: 0.281, CiteScore: 1)
J. of Entrepreneurship and Public Policy     Hybrid Journal   (Followers: 8, SJR: 0.262, CiteScore: 1)
J. of European Industrial Training     Hybrid Journal   (Followers: 2)
J. of European Real Estate Research     Hybrid Journal   (Followers: 3, SJR: 0.268, CiteScore: 1)
J. of Facilities Management     Hybrid Journal   (Followers: 4, SJR: 0.33, CiteScore: 1)
J. of Family Business Management     Hybrid Journal   (Followers: 7)
J. of Fashion Marketing and Management     Hybrid Journal   (Followers: 12, SJR: 0.608, CiteScore: 2)
J. of Financial Crime     Hybrid Journal   (Followers: 363, SJR: 0.228, CiteScore: 0)
J. of Financial Economic Policy     Hybrid Journal   (Followers: 1, SJR: 0.186, CiteScore: 0)
J. of Financial Management of Property and Construction     Hybrid Journal   (Followers: 8, SJR: 0.309, CiteScore: 1)
J. of Financial Regulation and Compliance     Hybrid Journal   (Followers: 8, SJR: 0.159, CiteScore: 0)
J. of Financial Reporting and Accounting     Hybrid Journal   (Followers: 13)
J. of Forensic Practice     Hybrid Journal   (Followers: 56, SJR: 0.205, CiteScore: 1)
J. of Global Mobility     Hybrid Journal   (Followers: 2, SJR: 0.377, CiteScore: 1)

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Journal Cover
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering
Journal Prestige (SJR): 0.22
Citation Impact (citeScore): 1
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0332-1649
Published by Emerald Homepage  [341 journals]
  • Analytical and numerical models of the magnetoacoustic tomography with
           magnetic induction
    • Pages: 538 - 548
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 538-548, March 2018.
      PurposeElectrical properties of biological tissues are known to be sensitive to physiological and pathological conditions of living organisms. For instance, human breast cancer or liver tumor cells have a significantly higher electrical conductivity than a healthy tissue. The paper aims to the new recently developed magnetoacoustic tomography with magnetic induction (MAT-MI) which can be deployed for electrical conductivity imaging of low-conductivity objects. Solving a test problem by using an analytical method is a useful exercise to check the validity of the more complex numerical finite element models. Such test problems are discussed in Chapter 3. The detailed analysis of an electromagnetic induction in low-conductivity objects is very important for the next steps in the tomographic process of image reconstruction. Finally, the image reconstruction examples for object’s complex shapes’ have been analyzed. The Lorentz force divergence reconstruction has been achieved with the help of time reversal algorithm. Design/methodology/approachIn given arrangements the magnetic field and eddy current vectors satisfy the Maxwell partial differential equations. Applying the separation of variables method analytical solutions are obtained for an infinitely long conducting cylindrical segment in transient magnetic field. A special case for such a configuration is an infinitely long cylinder with longitudinal crack. The analytical solutions are compared with those obtained by using numerical procedures. For complex shapes of the object, the MAT-MI images have been calculated with the help of the finite element method and time reversal algorithm. FindingsThe finite element model developed for a MAT-MI forward problem has been validated by analytical formulas. Based on such a confirmation, the MAT-MI complex model has been defined and solved. The conditions allowing successful MAT-MI image reconstruction have been provided taking into account different conductivity distribution. For given object’s parameters, the minimum number of measuring points allowing successful reconstruction has been determined. Originality/valueA simple test example has been proposed for MAT-MI forward problem. Analytical closed-form solutions have been used to check the validity of the made in-house finite element software. More complex forward and inverse problems have been solved using the software.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:19Z
      DOI: 10.1108/COMPEL-12-2016-0530
       
  • Application of PSO and TLBO algorithms with neural network for optimal
           design of electrical machines
    • Pages: 549 - 564
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 549-564, March 2018.
      PurposeThis study aims to focus on the application of the stochastic algorithms for optimal design of electrical machines. Among them, the authors are interested in particle swarm optimization and teaching–learning-based optimization. Design/methodology/approachThe optimization process is realized by the coupling of the above methods to finite element analysis of the electromagnetic field. FindingsTo improve the performance of these algorithms and reduce their computation time, a coupling with the artificial neuron network has been realized. Originality/valueThe proposed strategy is applied to solve two optimization problems: Team workshop problem 25 and switched reluctance motor with flux barriers.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:04Z
      DOI: 10.1108/COMPEL-12-2016-0532
       
  • Comparison of three space mapping techniques on electromagnetic design
           optimization
    • Pages: 565 - 580
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 565-580, March 2018.
      PurposeThis paper aims to investigate three low-evaluation-budget optimization techniques: output space mapping (OSM), manifold mapping (MM) and Kriging-OSM. Kriging-OSM is an original approach having high-order mapping. Design/methodology/approachThe electromagnetic device to be optimally sized is a five-phase linear induction motor, represented through two levels of modeling: coarse (Kriging model) and fine.The optimization comparison of the three techniques on the five-phase linear induction motor is discussed. FindingsThe optimization results show that the OSM takes more time and iteration to converge the optimal solution compared to MM and Kriging-OSM. This is mainly because of the poor quality of the initial Kriging model. In the case of a high-quality coarse model, the OSM technique would show its domination over the other two techniques. In the case of poor quality of coarse model, MM and Kriging-OSM techniques are more efficient to converge to the accurate optimum. Originality/valueKriging-OSM is an original approach having high-order mapping. An advantage of this new technique consists in its capability of providing a sufficiently accurate model for each objective and constraint function and makes the coarse model converge toward the fine model more effectively.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:35Z
      DOI: 10.1108/COMPEL-11-2016-0512
       
  • Optimal shape design of multi-layered IPMSM using adaptive dynamic Taylor
           Kriging model
    • Pages: 581 - 590
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 581-590, March 2018.
      PurposeThis paper aims to propose a numerically efficient multi-objective optimization strategy, which can improve both the efficiency and performance during the optimization process. Design/methodology/approachThis paper discusses the multi-objective optimization algorithm by combining multi-objective differential evolution (MODE) algorithm with an adaptive dynamic Taylor Kriging (ADTK) model. FindingsThe proposed approach is validated through application to an analytic example and applied to a shape optimal design of a multi-layered interior permanent magnet synchronous motor for torque ripple reduction while maintaining the average torque. Originality/valueThe ADTK model selects its basis functions adaptively and dynamically so that it may have better accuracy than any other Kriging models. Through adaptive insertion of new sampling data, it guarantees minimum required sampling data for a desired fitting accuracy.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:46Z
      DOI: 10.1108/COMPEL-12-2016-0527
       
  • Design by optimization of controlled static converters with EMC filters in
           aeronautics
    • Pages: 591 - 602
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 591-602, March 2018.
      PurposeWith the increasing number of onboard controlled static converters in aeronautics, methods to design lighter configurations are required. This study aims to help the designer sizing optimal electromagnetic compatibility (EMC) filters and, moreover, finding optimal voltage levels and switching frequency, which have a great impact on the design and global mass of such converters. Design/methodology/approachAnalytical models for capacitors, inductors and heatsink are settled. Using frequency modeling, EMC can be studied analytically. To deal with frequency and voltages variations, models of perturbations sources are developed. Concerning the problem of surveilling thousands of harmonics to check the whole frequency range of EMC standards in optimization, a strategy that drastically reduces the number of computations and has a good convergence is proposed. FindingsThe methods settled in the paper allow to optimize a controlled static converter with its EMC filters along with finding optimal switching frequency and voltage levels. A study on a three-phase rectifier reveals the importance of the switching frequency on converter design with EMC filters. A 28 per cent mass reduction is predicted by increasing the switching frequency from 10 to 30 kHz. The designed converters are verified by simulations. Research limitations/implicationsInvestigating the voltage levels along with the switching frequency has not been achieved yet for static controlled converters with EMC constraints. The approach lacks experimental validations, but it is currently ongoing. Originality/valueDealing analytically with the changes of frequency or voltages in an EMC study is a new feature. The possibility to use deterministic algorithm is essential for dealing with the important number of constraints and the numerous interactions between all the parts of the problem, especially EMC.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:42Z
      DOI: 10.1108/COMPEL-12-2016-0522
       
  • Optimal operation of building microgrids – comparison with mixed-integer
           linear and continuous non-linear programming approaches
    • Pages: 603 - 616
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 603-616, March 2018.
      PurposeThis paper aims to present two mathematical models to solve the Energy Management problem of a building microgrid (MG). In particular, it proposes a deterministic mixed integer linear programming (MILP) and non-linear programming (NLP) formulations. This paper focuses on the modelling process and the optimization performances for both approaches regarding optimal operation of near-zero energy buildings connected to an electric MG with a 24-h time horizon. Design/methodology/approachA general architecture of a MG is detailed, involving energy storage systems, distributed generation and a thermal reduced model of the grid-connected building. A continuous non-linear model is detailed along with linearizations for the mixed-integer liner formulation. Multi-physic, non-linear and non-convex phenomena are detailed, such as ventilation and air quality models. FindingsResults show that both approaches are relevant for solving the energy management problem of the building MG. Originality/valueIntroduction and modelling of the thermal loads within the MG. The resulting linear program handles the mutli-objective trade-off between discomfort and the cost of use taking into account air quality criterion. Linearization and modelling of the ventilation system behaviour, which is generally non-linear and non-convex equality constraints, involving air quality model, heat transfer and ventilation power. Comparison of both MILP and NLP methods on a general use case provides a solution that can be interpreted for implementation.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:58Z
      DOI: 10.1108/COMPEL-11-2016-0489
       
  • Pareto-based branch and bound algorithm for multiobjective optimization of
           a safety transformer
    • Pages: 617 - 629
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 617-629, March 2018.
      PurposeThis paper aims to propose a multiobjective branch and bound (MOBB) algorithm with a new criteria for the branching and discarding of nodes based on Pareto dominance and contribution metric. Design/methodology/approachA multiobjective branch and bound (MOBB) method is presented and applied to the bi-objective combinatorial optimization of a safety transformer. A comparison with exhaustive enumeration and non-dominated sorting genetic algorithm (NSGA2) confirms the solutions. FindingsIt appears that MOBB and NSGA2 are both sensitive to their control parameters. The parameters for the MOBB algorithm are the number of starting points and the number of solutions on the relaxed Pareto front. The parameters of NSGA2 are the population size and the number of generations. Originality/valueThe comparison with exhaustive enumeration confirms that the proposed algorithm is able to find the complete set of non-dominated solutions in about 235 times fewer evaluations. As this last method is exact, its confidence level is higher.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:41Z
      DOI: 10.1108/COMPEL-11-2016-0505
       
  • Improvement of topology optimization method based on level set function in
           magnetic field problem
    • Pages: 630 - 644
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 630-644, March 2018.
      PurposeThe purpose of this paper is the improvement of topology optimization. The scope of the paper is focused on the speedup of optimization. Design/methodology/approachTo achieve the speedup, the method of moving asymptotes (MMA) with constrained condition of level set function is applied instead of solving the Hamilton–Jacobi equation. FindingsThe acceleration of convergence of objective function is drastically improved by the implementation of MMA. Originality/valueNormally, the level set method is solved through the Hamilton–Jacobi equation. However, the possibility of introducing mathematical programming is clear by the constrained condition. Furthermore, the proposed method is suitable for efficiently solving the topology optimization problem in the magnetic field system.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:31Z
      DOI: 10.1108/COMPEL-12-2016-0528
       
  • Comparing life cycle cost and environmental impact optimizations of a low
           voltage dry type distribution transformer
    • Pages: 645 - 660
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 645-660, March 2018.
      PurposeLife cycle analysis (LCA) is more and more used in the context of electromagnetic product design. But it is often used to check a design solution regarding environmental impacts after technical and economical choices. This paper aims to investigate life cycle impact optimization (LCIO) and compare it with the classical life cycle cost optimization (LCCO). Design/methodology/approachFirst, a model of a dry-type transformer using different materials for windings and the magnetic core is presented. LCCO, which is a mixed continuous-discrete, multi-objective technico-economic optimization, is done using both deterministic and genetic algorithms. LCCO results and optimization performances are analyzed, and an LCA is presented for a set of optimal solutions. The final part is dedicated to LCIO, where the paper shows that these optimal solutions are close to those obtained with LCCO. FindingsThis paper investigated LCIO using an environmental impacts model that has been introduced in the optimization framework Component Architecture for the Design of Engineering Systems. The paper shows how a mixed continuous-discrete, multi-objective technico-economic optimization can be done using an efficient deterministic optimization algorithm such as Sequential Quadratic Programming. Thanks to the technico-economic-environmental model and the efficient optimization algorithm, both LCCO and LCIO were performed separately and together. It has been shown that optimal solutions are similar, leading to the conclusion that only one modeling is required (economic or environmental) but on the life cycle. Originality/valueThe classical sequential methodology of design is improved here by the use of a model of calculation of the environmental impacts allowing the optimization. This original optimization allowed the authors to show that an analysis of the life cycle from an economic point of view or from an environmental point of view led to quasi-equivalent technical solutions. The key is to take into account the life cycle of the product.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:00Z
      DOI: 10.1108/COMPEL-12-2016-0533
       
  • Use of SQP optimization algorithm to size a multiphysical system
    • Pages: 661 - 680
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 661-680, March 2018.
      PurposeStatic converters generate current harmonics in power grids. For numerous studies, analytical frequency modeling is preferred to carry out their harmonic modeling in the context of sizing by optimization. However, a design by optimization has to consider other constraints, e.g. modeling constraints and operating constraints. In this way, this paper aims to focus on applying an analytical frequency modeling on the sizing by optimization of an aircraft electrical power channel. Design/methodology/approachThe paper aims to size a multiphysical system by optimization. In this way, the sizing of an aircraft electrical power channel by optimization has been carried out. The models of all the channel components are analytical. Specifically, the frequency model of the power electronics is based on Tran et al. (2016) and is made of equalities and inequalities. Due to this modeling choice, the optimization satisfies hundreds of constraints, such as modeling constraints and static converter operating constraints. Furthermore, transient constraints are only verified after optimization. FindingsThe difficulty is the modeling of the system by taking into account nonlinear implicit equations having several solutions. A solution is the addition of inequality constraints to the model to guide the implicit solving. Furthermore, this greatly helps the optimization algorithm to find the good operating mode of the static converter, at steady state. This aspect is indispensable to validate the sizing model. Research limitations/implicationsThe number of the configurations per operating period of the static converters is defined a priori and limited. Originality/valueThe analytical model for the sizing is formulated as a constrained optimization problem. Its solving and the sizing by optimization are carried out by the same optimization algorithm.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:43Z
      DOI: 10.1108/COMPEL-12-2016-0519
       
  • Solving the electrical impedance tomography inverse problem for
           logarithmic conductivity
    • Pages: 681 - 690
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 681-690, March 2018.
      PurposeIn the context of electrical impedance tomography (EIT), this paper aims to evaluate limitations of estimating conductivity or resistivity, as well as the improvements achieved with the use of an alternate description of the solution space, the logarithmic conductivity. Design/methodology/approachA quantitative analysis is performed, solving the inverse EIT problem by using the Gauss–Newton and non-linear conjugate gradient methods for a numerical phantom of 15 elements. A property of symmetry is studied for the direct EIT problem for a phantom of 385,601 elements. FindingsSolving the inverse EIT problem in logarithmic conductivity is more robust to the initial guess, as solutions are kept within physical bounds (conductivity positiveness). Also, convergence is faster and less dependent on the final values of the estimates. Research limitations/implicationsLogarithmic conductivity provides an advantageous description of the solution space for the EIT inverse problem. Similar estimation problems might be subject to analogous conclusions. Originality/valueThis study provides a novel analysis, quantitatively comparing the effect of different variables to solve the inverse EIT problem.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:51Z
      DOI: 10.1108/COMPEL-11-2016-0501
       
  • A neural network for electromagnetic based ore sorting
    • Pages: 691 - 703
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 691-703, March 2018.
      PurposeThis paper aims to presents a novel application of neural network (NN) pattern recognition to ore rock sorting using inductive electromagnetic (EM) sensors. Design/methodology/approachThe impedance of a metallic rock can be measured with an inductive method based on Faraday’s law and eddy current theory. A virtual rock model is then created for the simulation of the EM measurements. An NN is trained to differentiate between waste and useful ore samples (containing high amount of minerals) based on the EM sensor signals produced by the rocks. FindingsThe NN solution showed high accuracy of rock classification and produced relatively robust results from signals with noise. Originality/valueA pattern recognition NN was applied to classify low- and high-grade ore samples. It has the potential to determine the approximate amount of conductive materials inside ore rocks through multiple classes. This method can be used to improve the performance of EM-based ore sorting for mineral pre-concentration.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:33Z
      DOI: 10.1108/COMPEL-12-2016-0529
       
  • Comparative study of methods for optimization of electromagnetic devices
           with uncertainty
    • Pages: 704 - 717
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 704-717, March 2018.
      PurposeThis paper compares six reliability-based design optimization (RBDO) approaches dealing with uncertainties for a simple mathematical model and a multidisciplinary optimization problem of a safety transformer to highlight the most effective. Design/methodology/approachThe RBDO and various approaches to calculate the probability of failure are is presented. They are compared in terms of precision and number of evaluations on mathematical and electromagnetic design problems. FindingsThe mathematical example shows that the six RBDO approaches have almost the same results except the approximate moment approach that is less accurate. The optimization of the safety transformer highlights that not all the methods can converge to the global solution. Performance measure approach, single-loop approach and sequential optimization and reliability assessment (SORA) method appear to be more stable. Considering both numerical examples, SORA is the most effective method among all RBDO approaches. Originality/valueThe comparison of six RBDO methods on the optimization problem of a safety transformer is achieved for the first time. The comparison in terms of precision and number of evaluations highlights the most effective ones.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:53Z
      DOI: 10.1108/COMPEL-11-2016-0502
       
  • Topology optimization of magnetic shielding using level-set function
           combined with element-based topological derivatives
    • Pages: 718 - 729
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 718-729, March 2018.
      PurposeShape optimization using the level-set method is one of the most effective automatic design tools for electromagnetic machines. While level-set method has the advantage of being able to suppress unfeasible shape, it has a weakness of being unable to handle complex topology changes such as perforate at material region. With this method, it is only possible to define simple connected topology, and it is difficult to determine the optimal shape which has holes. Therefore, it is important to efficiently expand the searching area in the optimization process with level-set method. Design/methodology/approachIn this paper, the authors introduce the newly defined hole sensitivity which is based on concept of topological derivatives, and combine it with level-set method to effectively create holes in the search process. Furthermore, they consider a variable bandwidth of gray scale, which indicates the transition width between air and magnetic body and combine it with the hole creation method described above. With these methods, the authors aim to expand the searching area in comparison with the conventional level-set method. FindingsAs a result of applying the proposed methods to a magnetic shielding problem, the multi-layered shielding which effectively reduces the magnetic flux in the target area, is successfully produced. Originality/valueThe proposed methods enable us to effectively create a hole and to expand the searching area in the topology optimization process unlike in the case of conventional level-set method.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:48Z
      DOI: 10.1108/COMPEL-12-2016-0524
       
  • Optimal design of spoke type motor and magnetizer using FEM and RSM
    • Pages: 730 - 739
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 730-739, March 2018.
      PurposeThis study aims to propose criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration. Design/methodology/approachThe optimal design of the stator and rotor can be enhanced using both a response surface method (RSM) and finite element method (FEM). In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor. FindingsThe criteria not only improve performance but also reduce manufacturing costs. The criteria are verified FEM together with an RSM. These methods are used to optimize the stator and rotor shape and the magnetization system. These methods allow us to produce an efficient system for mass production of the motor. Originality/valueThis study proposed a design method that uses rare earth magnets in a system to replace the spoke-type IPM. To verify the optimal design, torque characteristics were analysed using FEM and RSM. Excellent results were achieved regarding the reduction of cogging torque and torque ripple. In addition, the design of the magnetizer enables a cost-effective mass production system for the motor.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:15Z
      DOI: 10.1108/COMPEL-12-2016-0536
       
  • Application of the corrected response surface methodology for the
           optimization of a permanent magnet synchronous machine
    • Pages: 740 - 754
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 740-754, March 2018.
      PurposeThis paper aims to introduce an original application of the corrected response surface method (CRSM) in the context of the optimal design of a permanent magnet synchronous machine used as an integrated starter generator. This method makes it possible to carry out this design in a very efficient manner, in comparison with conventional optimization approaches. Design/methodology/approachThe search for optimal conditions is achieved by the joint use of two multi-physics models of the machine to be optimized. The former models most finely the physical functioning of the machine; it is called “fine model”. The second model describes the same physical phenomena as the fine model but must be much quicker to evaluate. Thus, to minimize its evaluation time, it is necessary to simplify it considerably. It is called “coarse model”. The lightness of the coarse model allows it to be used intensively by conventional optimization algorithms. On the other hand, the fine reference model makes it possible to recalibrate the results obtained from the coarse model at any instant, and mainly at the end of each classical optimization. The difference in definition between fine and coarse models implies that these two models do not give the same output values for the same input configuration. The approach described in this study proposes to correct the values of the coarse model outputs by constructing an adjustment (correcting) response surface. This gives the name to this method. It then becomes possible to have the entire load of the optimization carried over to the coarse model adjusted by the addition of this correction response surface. FindingsThe application of this method shows satisfactory results, in particular in comparison with those obtained with a traditional optimization approach based on a single (fine) model. It thus appears that the approach by CRSM makes it possible to converge much more quickly toward the optimal configurations. Also, the use of response surfaces for optimization makes it possible to capitalize the modeling data, thus making it possible to reuse them, if necessary, for subsequent optimal design studies. Numerous tests show that this approach is relatively robust to the variations of many important functioning parameters. Originality/valueThe CRSM technique is an indirect multi-model optimization method. This paper presents the application of this relatively undeveloped optimization approach, combining the features and benefits of (Indirect) efficient global optimization techniques and (multi-model) space mapping methods.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:23Z
      DOI: 10.1108/COMPEL-11-2016-0480
       
  • Nonlinear analysis of VCO jitter generation using Volterra series
    • Pages: 755 - 771
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 755-771, March 2018.
      PurposeCharge pump phase locked loops (CPPLLs) are nonlinear systems as a result of the nonlinear behavior of voltage-controlled oscillators (VCO). This paper aims to specify jitter generation of voltage controlled oscillator phase noise in CPPLLs, by considering approximated practical model for VCO. Design/methodology/approachCPPLL, in practice, shows nonlinear behavior, and usually in LC-VCOs, it follows second-degree polynomial function behavior. Therefore, the nonlinear differential equation of the system is obtained which shows the CPPLLs are a nonlinear system with memory, and that Volterra series expansion is useful for such systems. FindingsIn this paper, by considering approximated practical model for VCO, jitter generation of voltage controlled oscillator phase noise in CPPLLs is specified. Behavioral simulation is used to validate the analytical results. The results show a suitable agreement between analytical equations and simulation results. Originality/valueThe proposed method in this paper has two advantages over the conventional design and analysis methods. First, in contrast to an ideal CPPLL, in which the characteristic of the VCO’s output frequency based on the control voltage is linear, in the present paper, a nonlinear behavior was considered for this characteristic in accordance with the real situations. Besides, regarding the simulations in this paper, a behavior similar to the second-degree polynomial was considered, which caused the dependence of the produced jitter’s characteristic corner frequency on the jitter’s amplitude. Second, some new nonlinear differential equations were proposed for the system, which ensured the calculation of the produced jitter of the VCO phase noise in CPPLLs. The presented method is general enough to be used for designing the CPPLL.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:36Z
      DOI: 10.1108/COMPEL-04-2017-0166
       
  • Nonlinear impedance boundary condition for 2D BEM
    • Pages: 772 - 783
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 772-783, March 2018.
      PurposeThe purpose of this paper is the derivation and efficient implementation of surface impedance boundary conditions (SIBCs) for nonlinear magnetic conductors. Design/methodology/approachAn approach based on perturbation theory is proposed, which expands to nonlinear problems the methods already developed by the authors for linear problems. Differently from the linear case, for which the analytical solution of the diffusion equation in the semi-infinite space for the magnetic field is available, in the nonlinear case the corresponding nonlinear diffusion equation must be solved numerically. To this aim, a suitable smooth map is defined to reduce the semi-infinite computational domain to a finite one; then the diffusion equation is solved by a Galerkin method relying on basis functions constructed via the push-forward of a Lagrangian polynomial basis whose degrees of freedom are collocated at Gauss–Lobatto nodes. The use of such basis in connection with a suitable under-integration naturally leads to mass-lumping without impacting the order of the method. The solution of the diffusion equation is coupled with a boundary element method formulation for the case of parallel magnetic conductors in terms of E and B fields. FindingsThe results are validated by comparison with full nonlinear finite element method simulations showing very good accordance at a much lower computational cost. Research limitations/implicationsLimitations of the method are those arising from perturbation theory: the introduced small parameter must be much less than one. This implies that the penetration depth of the magnetic field into the magnetic and conductive media must be much smaller than the characteristic size of the conductor. Originality/valueThe efficient implementation of a nonlinear SIBC based on a perturbation approach is proposed for an electric and magnetic field formulation of the two-dimensional problem of current driven parallel solid conductors.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:34Z
      DOI: 10.1108/COMPEL-01-2017-0035
       
  • Observer based control scheme for DC-DC boost converter using
           sigma–delta modulator
    • Pages: 784 - 798
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 784-798, March 2018.
      PurposeIn actual application of a DC-DC boost converter, the input voltage and resistive load may be changed frequently, and these variations deteriorate the conventional controller performance. The purpose of this paper is to present an observer-based control scheme for a DC-DC boost converter with an unknown resistive load and input voltage. Design/methodology/approachTo estimate the unknown input voltage and resistive load, a nonlinear observer is designed by using the Lyapunov stability theorem. In addition, the closed-loop stability of the proposed control scheme for the DC-DC boost converter is proven. To convert the continuous control input to discrete mode, a sigma–delta modulator is used. FindingsThe proposed control scheme is validated in different situations. The adaptive structure of the proposed control scheme is tested by the input voltage, load and reference signal variation, and the simulation results confirm the capability of the proposed observer-based control strategy. Originality/valueThe contribution of this paper is twofold: according to nonlinear controller design, the feedforward term of the nonlinear controller is obtained via the observer, and unlike the proportional–integral controller, performance deterioration in the input voltage and load variations are unraveled. The effectiveness of this method is validated by experimental implementation in the presence of load and input voltage variations, and the experimental results confirm the efficacy of the proposed strategy.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:47Z
      DOI: 10.1108/COMPEL-02-2017-0102
       
  • An approach based on ANFIS and input selection procedure for microwave
           characterization of dielectric materials
    • Pages: 799 - 813
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 799-813, March 2018.
      PurposeThe principle of microwave characterization of dielectric materials using open-ended coaxial line probe is to link the dielectric properties of the sample under test to the measurements of the probe admittance (Y(f) = G(f)+ jB(f )). The purpose of this paper is to develop an alternative inversion tool able to predict the evolution of the complex permittivity (ε = ε′ – jε″) on a broad band frequency (f from 1 MHz to 1.8 GHz). Design/methodology/approachThe inverse problem is solved using adaptive network based fuzzy inference system (ANFIS) which needs the creation of a database for its learning. Unfortunately, train ANFIS using f, G and B as inputs has given unsatisfying results. Therefore, an inputs selection procedure is used to select the three optimal inputs from new inputs, created mathematically from original ones, using the Jang method. FindingsInversion results of measurements give, after training, in real time the complex permittivity of solid and liquid samples with a very good accuracy which prove the applicability of ANFIS to solve inverse problems in microwave characterization. Originality/valueThe originality of this paper consists on the use of ANFIS with input selection procedure based on the Jang method to solve the inverse problem where the three optimal inputs are selected from 26 new inputs created mathematically from original ones (f, G and B).
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:20Z
      DOI: 10.1108/COMPEL-05-2017-0208
       
  • Analytical study and simulation of a transformer-less photovoltaic
           grid-connected inverter with a delta-type tri-direction clamping cell for
           leakage current elimination
    • Pages: 814 - 831
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 814-831, March 2018.
      PurposeThis paper aims to propose a new transformer-less inverter structure to reduce the common-mode leakage current in grid-connected photovoltaic (PV) systems. Design/methodology/approachThe proposed circuit structure is the same as the conventional full-bridge inverter with three additional power switches in a triangular structure. These three power switches are between the bridge and the output filter, and they mitigate the common-mode leakage current flowing toward the PV panels’ capacitors. The common-mode leakage current mitigation is done through the three-direction clamping cell (TDCC) concept. By clamping the common-mode voltage to the middle voltage of the DC-link capacitors, the leakage current and the total harmonic distortion (THD) of the injected current to the grid is effectively reduced. Therefore, the efficiency is improved. FindingsThe switching modes and the control method are introduced. A comparison is carried out between the proposed structure and other solutions in the literature. The proposed topology and its respective control method are simulated by PSCAD/EMTDC software. The simulation results validate the advantages of the presented structure such as clamping the common-mode voltage and reducing leakage current and THD of injected current to the grid. Originality/valuePresenting a single phase-improved inverter structure with low-leakage current for grid-connected PV power systems represents a significant original contribution to this work. The proposed structure can inject a sinusoidal current with low THD to the AC grid, and the power factor is unity on the AC side. In the half positive cycle, one of the switches in the TDCC is turned off under zero current. Besides, one of the other switches in TDCC is turned on with zero voltage and, therefore, its turn-on switching losses are zero. The efficiency of the proposed topology is high because of the reduction of leakage current and power losses. Accordingly, the presented topology can be a good solution to the leakage current elimination.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:29Z
      DOI: 10.1108/COMPEL-03-2017-0114
       
  • Taylor series expansion for evaluating the bounds of electric potentials
           in an electrostatic system with interval parameters
    • Pages: 832 - 848
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 832-848, March 2018.
      PurposeUncertainty is ubiquitous in practical engineering and scientific research. The uncertainties in parameters can be treated as interval numbers. The prediction of upper and lower bounds of the response of a system including uncertain parameters is of immense significance in uncertainty analysis. This paper aims to evaluate the upper and lower bounds of electric potentials in an electrostatic system efficiently with interval parameters. Design/methodology/approachThe Taylor series expansion is proposed for evaluating the upper and lower bounds of electric potentials in an electrostatic system with interval parameters. The uncertain parameters of the electrostatic system are represented by interval notations. By performing Taylor series expansion on the electric potentials obtained using the equilibrium governing equation and by using the properties of interval mathematics, the upper and lower bounds of the electric potentials of an electrostatic system can be calculated. FindingsTo evaluate the accuracy and efficiency of the proposed method, the upper and lower bounds of the electric potentials and the computation time of the proposed method are compared with those obtained using the Monte Carlo simulation, which is referred to as a reference solution. Numerical examples illustrate that the bounds of electric potentials of this method are consistent with those obtained using the Monte Carlo simulation. Moreover, the proposed method is significantly more time-saving. Originality/valueThis paper provides a rapid computational method to estimate the upper and lower bounds of electric potentials in electrostatics analysis with interval parameters. The precision of the proposed method is acceptable for engineering applications, and the computation time of the proposed method is significantly less than that of the Monte Carlo simulation, which is the most widely used method related to uncertainties. The Monte Carlo simulation requires a large number of samplings, and this leads to significant runtime consumption.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:25Z
      DOI: 10.1108/COMPEL-05-2017-0200
       
  • An energy-efficient scalar control taking core losses into account
    • Pages: 849 - 867
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 849-867, March 2018.
      PurposeIn the need to optimize the energy efficiency, control structures can have a positive effect by tracking the optimal operating point according to the speed and mechanical load of the motor. The purpose of this paper is to present an energy-efficient scalar control for squirrel-cage induction motors (IMs), taking into consideration the effect of core losses. Design/methodology/approachThe proposed technique is based on the modification of the stator flux reference, to track the best efficiency point. The optimal flux values are computed through an improved model of the IM including core losses, then stored in a look-up table. FindingsSimulations of the proposed scalar control are carried out, and results show the efficiency improvement when the flux is optimized especially at low load cases. Results were validated experimentally on two motors compliant with different efficiency standards. Practical implicationsThe proposed approach can be used in several fields and applications using the scalar-controlled IM with a proper implementation in variable speed drives, as in the cases of pumps, compressors and blowers. Originality/valueThe proposed technique is compared to existing optimization methods in literature, and the results show an improvement in the dynamic performance and in the response delays. The approach is also compared to an optimization technique used in industries like Leroy-Somer for variable speed drives, and efficiency improvements are shown.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:47Z
      DOI: 10.1108/COMPEL-08-2017-0324
       
  • Design and simulation of electro-thermal compliant MEMS logic gates
    • Pages: 868 - 889
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 868-889, March 2018.
      PurposeThe purpose of this paper is to design an out-of-plane micro electro-thermal-compliant actuator based logic gates which work analogously to complementary metal oxide semiconductor (CMOS) based logic gates. The proposed logic gates used a single-bit mechanical micro ETC actuator per logic instead of using 6-14 individual transistors as in CMOS. Design/methodology/approachA complete analytical modelling is performed on a single ETC vertical actuator, and a relation between the applied voltage and the out-of-plane deflection is derived. Its coupled electro-thermo-mechanical analysis is carried out using micro electro mechanical system (MEMS) CAD tool CoventorWare to illustrate its performance. FindingsThis paper reports analytical and numerical simulation of basic MEMS ETC actuator-based logic gates. The proposed logic gate operates on 5 V, which suits well with conventional CMOS logic, which in turn reduces the power consumption of the device. Originality/valueThe proposed logic gates uses a single-bit MEMS ETC actuator per logic instead of using more transistors as in CMOS. The unique feature of this proposed logic gates is that the basic mechanical ETC actuator is customized in its structure to function as specific logic gates depending upon the given inputs.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:49Z
      DOI: 10.1108/COMPEL-08-2017-0325
       
  • Design and prototyping of the novel axial flux-switching permanent-magnet
           motor
    • Pages: 890 - 910
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 890-910, March 2018.
      PurposeThe purpose of this paper is to propose a novel axial field flux-switching machine with sandwiched permanent magnets. It is one of the most efficient machines which is appropriate for high-torque and low-speed direct-drive applications. The proposed model is equipped with an advanced phase-group concentrated-coil winding to obtain a unity displacement winding factor. Two configurations of the proposed motors with 6-stator-slot (S)/10-rotor-pole (P) and 12S/19P are investigated. These two structures are compared with optimized a conventional axial-field flux-switching permanent-magnet (CAFFSPM) machine. Unity displacement winding factor increases the back-EMF and electromagnetic torque. Moreover, the prototype 12S/19P motor is built to verify the design. Design/methodology/approachThe torque equation is obtained and the dimensions of the two proposed motors are determined. Some specific design issues, including the stator/rotor pole sandwiching pole angle, the stator tooth angle and the rotor pole angle have been optimized to minimize the cogging torque while maintaining the high torque density by means of response surface methodology (RSM) and 3-D finite element model of the machine. FindingsTo improve the performance, especially at high torque density, low cogging torque and high level of fault-tolerant capability, the 12S/19P axial field flux-switching sandwiched permanent-magnet (AFFSSPM) motor is proposed. Based on the optimized design, a prototype of the 12S/19P AFFSSPM motor is fabricated and tested. It is found that the experimental results validate the 3-D finite element method (FEM) simulation results. Originality/valueThe AFFSSPM motor is one of the most efficient motors, but the 12S/19P AFFSSPM motor with sandwiched permanent magnet and unity displacement winding factor has not been specially reported to date. Thus, in this paper, the authors report on optimal design of a novel axial flux-switching sandwiched permanent-magnet machine for electric vehicles and fabricate a prototype of the 12S/19P AFFSSPM motor.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:38Z
      DOI: 10.1108/COMPEL-05-2017-0213
       
  • Event triggered non-inverting chopper fed networked DC motor speed
           synchronization
    • Pages: 911 - 929
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 911-929, March 2018.
      PurposeThis paper aims to provide a new approach to address the problem of reaching the synchronous speed in the network connected multiple motors. Design/methodology/approachPractically, all the control approaches require continuous monitoring of the system thereby consuming extra energy. The method proposed in this paper uses an event-based approach with the multi-agent system (MAS) consensus control alongside with linear quadratic regulator control, thus saving a larger amount of energy. The proposed system is developed by using non-inverting buck boost chopper to provide necessary electrical power for the direct current motor, hence creating a single agent of bigger MAS with identical dynamics. The system stability is formulated by using Lyapunov stability theory. The proposed system is simulated via MATLAB. FindingsThe acquired simulated results validate that the proposed methodology and the multi-motor system worked successfully, thereby achieving common speed, i.e. consensus. The proposed system also validates the energy-saving concept. Practical implicationsPresently, the multiple motor synchronous speed system found application in paper-making machines, textile printing machines, offset printing, etc. The proposed study will contribute greatly to the existing methodologies and overcome their deficiencies by making the system more flexible and error-free due to the presence of network connectivity. Originality/valueThe system is simulated to verify theoretical concepts.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:06Z
      DOI: 10.1108/COMPEL-09-2017-0397
       
  • Predicting the unstable period-1 orbit (UPO-1) of DC–DC converters by
           extracting harmonic content
    • Pages: 930 - 947
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 930-947, March 2018.
      PurposeThis study aims to predict the unstable period-1 orbit (UPO-1) of DC–DC converters and find analytical expressions to describe it. Design/methodology/approachNonlinear dynamical phenomena of a peak–current–mode controlled direct current–direct current (DC–DC) Boost converter are discussed briefly first. Then fast fourier transform (FFT) analysis of state variables under different dynamic states is provided, and the characteristic of the harmonic content in different states is summarized. Following these, a scientific hypothesis on the harmonic content of the UPO-1 is presented, and the Equivalent Small Parameter method is adopted then, thus analytic-form expressions of the UPO-1 can be derived. FindingsAccording to results of theoretical analysis, numerical simulations and experiments, this paper illustrates that, like stable period-1 orbit, the UPO-1 is also made up of the DC component and harmonics with integer times of switching frequency. Originality/valueThis work provides an unreported approach for extracting the UPO-1 of DC–DC converters, which is mainly based on predicting the harmonic structure information of the orbit. According to experimental parts of the work, it shows that the stabilizer can be designed easier by using the proposed method. Additionally, from a broader perspective, the results could also have implications in a wide class of forced oscillation systems.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:39Z
      DOI: 10.1108/COMPEL-06-2017-0256
       
  • Defect localization and characterization in eddy current nondestructive
           testing by change detection and global optimization
    • Pages: 948 - 970
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 948-970, March 2018.
      PurposeThis paper aims to present a data-processing methodology combining kernel change detection (KCD) and efficient global optimization algorithms for solving inverse problem in eddy current non-destructive testing. The main purpose is to reduce the computation cost of eddy current data inversion, which is essentially because of the heavy forward modelling with finite element method and the non-linearity of the parameter estimation problem. Design/methodology/approachThe KCD algorithm is adapted and applied to detect damaged parts in an inspected conductive tube using probe impedance signal. The localization step allows in reducing the number of measurement data that will be processed for estimating the flaw characteristics using a global optimization algorithm (efficient global optimization). Actually, the minimized objective function is calculated from data related to defect detection indexes provided by KCD. FindingsSimulation results show the efficiency of the proposed methodology in terms of defect detection and localization; a significant reduction of computing time is obtained in the step of defect characterization. Originality/valueThis study is the first of its kind that combines a change detection method (KCD) with a global optimization algorithm (efficient global optimization) for defect detection and characterization. To show that such approach allows to reduce the numerical cost of ECT data inversion.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:27Z
      DOI: 10.1108/COMPEL-05-2017-0201
       
  • Modified MPC based grid-connected five-level inverter for photovoltaic
           applications
    • Pages: 971 - 985
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 971-985, March 2018.
      PurposeThe main purpose of this paper is to select appropriate voltage vectors in the switching techniques and, by selecting the proper voltage vectors, be able to achieve a DC link with the same outputs and a symmetric multi-level inverter. Design/methodology/approachThe proposed structure, a two-stage DC–AC symmetric multi-level inverter with modified Model Predictive Control (MMPC) method, is presented for Photovoltaic (PV) applications. The voltage of DC-link capacitors of the boost converter is controlled by MMPC control method to select appropriate switching vectors for the multi-level inverter. The proposed structure is provided for single-phase power system, which increases 65 V input voltage to 220 V/50 Hz output voltage, with 400 V DC link. Simulation results of proposed structure with MMPC method are carried out by PSCAD/EMTDC software. FindingsBased on the proposed structure and control method, total harmonic distortion (THD) reduces, which leads to lower power losses and higher circuit reliability. In addition, reducing the number of active switches in current path causes to lower voltage stress on the switches, lower PV leakage current and higher overall efficiency. Originality/valueIn the proposed structure, a new control method is presented that can make a symmetric five-level voltage with lower THD by selecting proper switching for PV applications.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:38:16Z
      DOI: 10.1108/COMPEL-02-2017-0056
       
  • Numerical modelling on partial discharge in HVDC XLPE cable
    • Pages: 986 - 999
      Abstract: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Volume 37, Issue 2, Page 986-999, March 2018.
      PurposeHigh voltage direct current (HVDC) cable is an important part in the electric power transmission and distribution systems. However, very little research has been carried out on partial discharge under direct current (DC) conditions. Niemeyer’s model has been widely used under alternating current (AC) conditions. This paper aims to intend to modify the Niemeyer’s model considering both electric field and charge dynamics under DC conditions, and therefore proposes a numerical model describing partial discharge characteristics in HVDC cable. Design/methodology/approachThis paper intends to understand partial discharge characteristics under DC conditions through numerical modelling. Niemeyer’s model that has been widely used under AC conditions has been modified, taking both electric field and charge dynamics under DC conditions into consideration. The effects of loading level or current through the conductor, cavity location and material properties on partial discharges have also been studied. FindingsElectrical conductivity is important in determining the characteristics of partial discharge under DC conditions and discharges tend to happen in short when the cavity field exceeds the inception level under the parameter values studied in the paper. Research limitations/implicationsBuilding the numerical model is the purpose of the paper, and there is lack in experiment and the comparison between the simulation results and experiment. Practical implicationsThe proposed model provides the numerical model describing partial discharge in HVDC cable and helps understand the partial discharge mechanism under DC voltage. Originality/valueTo the best of the author’s knowledge, this paper is a very early research on the numerical modelling work on partial discharge under DC voltage.
      Citation: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering
      PubDate: 2018-04-09T10:37:55Z
      DOI: 10.1108/COMPEL-07-2017-0297
       
 
 
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