Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Estimation of electromagnetic material properties with application to high-voltage power cables
Linnaeus University, Faculty of Technology, Department of Physics and Electrical Engineering.
2017 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Efficient design of high-voltage power cables is important to achieve an economical delivery of electric power from wind farms and power plants over the very long distances as well as the overseas electric power. The main focus of this thesis is the investigation of electromagnetic losses in components of high-voltage power cables. The objective of the ongoing research is to develop the theory and optimization techniques as tools to make material choices and geometry designs to minimize the high-frequency attenuation and dispersion for HVDC power cables and the power losses associated with HVAC cables. Physical limitations, dispersion relationships and the application of sum rules as well as convex optimization will be investigated to obtain adequate physical insight and a priori modeling information for these problems.

For HVAC power cables, the objectives are addressed by performing measurements and estimation of complex valued permeability of cable armour steel in Papers I and II. Efficient analytical solutions for the electromagnetic field generated by helical structures with applications for HVAC power cables have been obtained in Paper III.

For HVDC power cables, estimation of insulation characteristics from dielectric spectroscopy data using Herglotz functions, convex optimization and B-splines, has been investigated in Papers V and VI. The unique solution requirements in waveguide problems have been reviewed in Paper IV.

Place, publisher, year, edition, pages
Linnaeus University Press, 2017. , 19 p.
Series
Lnu Licentiate, 2
Keyword [en]
Material losses, power cables, cylindrical multipole expansion, Herglotz functions, convex optimization, sum rules
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Waves and Signals
Identifiers
URN: urn:nbn:se:lnu:diva-64265ISBN: 978-91-88357-77-9 (print)OAI: oai:DiVA.org:lnu-64265DiVA: diva2:1107212
Presentation
2017-06-14, C1202, Newton, Hus C, Växjö, 10:15 (English)
Opponent
Supervisors
Funder
Swedish Foundation for Strategic Research , AM13-0011
Available from: 2017-06-09 Created: 2017-06-09 Last updated: 2017-09-01Bibliographically approved
List of papers
1. Measurements and estimation of the complex valued permeability of magnetic steel
Open this publication in new window or tab >>Measurements and estimation of the complex valued permeability of magnetic steel
2015 (English)Report (Other academic)
Abstract [en]

This report is intended as a tutorial on electromagnetic modeling to measure and estimate the complex valued relative permeability of magnetic steel. The main application is with the estimation of the electromagnetic material parameters of the armour wires used with high-voltage AC power cables.

When the magnetic field intensity is sufficiently far from saturating the magnetic steel, the magnetic hysteresis phenomena can be approximated by using a linearization approach based on a complex valued (and frequency and amplitude dependent) relative permeability. In the report it is demonstrated how the complex valued permeability of magnetic steel can be efficiently estimated in the presence of a strong skin-effect. This is achieved by using a simple transformer coil built on the magnetic steel to be tested and by efficient numerical modeling based on waveguide theory and complex analysis. Numerical computations based on the Finite Element Method (FEM) and the commercial software COMSOL are employed to establish when edge effects can be ignored in the simplified analytical model.

Publisher
29 p.
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-48445 (URN)
Funder
Swedish Foundation for Strategic Research
Available from: 2015-12-18 Created: 2015-12-18 Last updated: 2017-06-09Bibliographically approved
2. Estimation of complex valued permeability of cable armour steel
Open this publication in new window or tab >>Estimation of complex valued permeability of cable armour steel
2016 (English)In: 2016 URSI International Symposium on Electromagnetic Theory (EMTS), IEEE Press, 2016Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a model based technique to estimate the complex valued permeability of cable armour steel. An efficient analytical model is derived for the linearized mutual impedance of a transformer coil built on a core of magnetic armour steel. A numerical residue calculation is used to solve the related inverse problem based on impedance data. The analytical model is validated using commercial finite element (FEM) software to establish that edge effects can be neglected. The numerical residue calculation is investigated by studying its convergence based on a simple rectangular quadrature rule in comparison to the composite Simpson's rule. When there are no measurement errors, both methods converge with an unexpected high order (superconvergence). However, in practice the estimation performance will be governed by measurement and model errors. Assuming that there are Gaussian measurement errors, the present performance of the estimation technique is quantified and investigated by means of the Cramér-Rao lower bound. In future, the proposed method will be useful as an input to general calculations of power losses in three-phase power cables.

Place, publisher, year, edition, pages
IEEE Press, 2016
National Category
Signal Processing
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-59499 (URN)10.1109/URSI-EMTS.2016.7571532 (DOI)978-1-5090-2503-9 (ISBN)978-1-5090-2502-2 (ISBN)
Conference
International Symposium on Electromagnetic Theory (EMTS 2016, 14–18 August 2016 in Espoo, Finland
Available from: 2016-12-23 Created: 2016-12-23 Last updated: 2017-06-09Bibliographically approved
3. Cylindrical multipole expansion for periodic sources with applications for three-phase power cables
Open this publication in new window or tab >>Cylindrical multipole expansion for periodic sources with applications for three-phase power cables
Show others...
2016 (English)In: Mathematical methods in the applied sciences, ISSN 0170-4214, E-ISSN 1099-1476Article in journal (Refereed) Epub ahead of print
Abstract [en]

This paper presents a c ylindrical multipole expansion for periodic sources with applications for three-phase power cables.It is the aim of the contribution to provide some analytical solutions and techniques that can be useful in the calculation ofcable losses. Explicit analytical results are given for the fields generated by a three-phase helical current distribution andwhich can be computed efficiently as an input to other numerical methods such as, for example , the Method of Moments.It is shown that the field computations are numerically stable at low frequencies (such as 50 Hz) as well as in the quasi-magnetostatic limit provided that sources are divergence-free. The cylindrical multipole expansion is fur thermore usedto derive an efficient analytical model of a measurement coil to measure and estimate the complex valued permeability ofmagnetic steel armour in the presence of a strong skin-effect.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Signal Processing
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-59497 (URN)10.1002/mma.3992 (DOI)
Available from: 2016-12-23 Created: 2016-12-23 Last updated: 2017-09-14
4. On absence of sources at infinity and uniqueness for waveguide solutions
Open this publication in new window or tab >>On absence of sources at infinity and uniqueness for waveguide solutions
2016 (English)In: Proceedings of the 2016 18th International Conference on Electromagnetics in Advanced Applications, ICEEA 2016, IEEE Press, 2016, 780-783 p.Conference paper, Published paper (Refereed)
Abstract [en]

This paper discusses criteria for establishing uniqueness of wave propagation problems. Causality, or passivity that implies causality, is adopted as the fundamental principle. It is stressed that radiation conditions are not applicable for waveguide modes that carry no active power. The Jones' criteria for causality in the frequency domain, which covers the convectively unstable case, are presented and analysed, the vanishing absorption principle, VAP, in particular. It is proposed to use L2 for a lossy medium but a weighted L2 for the lossless case.

Place, publisher, year, edition, pages
IEEE Press, 2016
National Category
Mathematical Analysis
Research subject
Mathematics, Applied Mathematics; Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-60614 (URN)10.1109/ICEAA.2016.7731515 (DOI)978-1-4673-9811-4 (ISBN)978-1-4673-9810-7 (ISBN)
Conference
2016 18th International Conference on Electromagnetics in Advanced Applications, ICEEA, 19-23 Sept. 2016
Available from: 2017-02-09 Created: 2017-02-09 Last updated: 2017-06-09Bibliographically approved
5. Approximation of dielectric spectroscopy data with Herglotz functions on the real line and convex optimization
Open this publication in new window or tab >>Approximation of dielectric spectroscopy data with Herglotz functions on the real line and convex optimization
2016 (English)In: Proceedings of the  2016 18th International Conference on Electromagnetics in Advanced Applications, IEEE, 2016, 863-866 p.Conference paper, Published paper (Refereed)
Abstract [en]

This paper describes the ongoing research on approximation of frequency dielectric spectroscopy measurement data. The algorithm based on passive approximation, Hilbert transform and Tikhonov regularization for non-uniformly sampled data is derived. The interpolation and extrapolation problems with application to the dielectric spectroscopy measurement data are solved using convex optimization. 

Place, publisher, year, edition, pages
IEEE, 2016
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-64263 (URN)10.1109/ICEAA.2016.7731537 (DOI)9781467398114 (ISBN)
Conference
2016 18th International Conference on Electromagnetics in Advanced Applications, ICEAA, 19-23 Sept. Cairns, Australia, 2016
Funder
Swedish Foundation for Strategic Research , AM13-0011
Available from: 2017-05-22 Created: 2017-05-22 Last updated: 2017-06-09Bibliographically approved
6. Passive approximation and optimization with B-splines
Open this publication in new window or tab >>Passive approximation and optimization with B-splines
Show others...
2017 (English)Report (Other academic)
Abstract [en]

A passive approximation problem is formulated where the target function is an arbitrary complex valued continuous function defined on an approximation domain consisting of a closed interval of the real axis. The approximating function is any Herglotz function with a generating measure that is absolutely continuous with Hölder continuous density in an arbitrary neighborhood of the approximation domain. The norm used is induced by any of the standard Lp-norms where 1 ≤ p ≤ ∞. The problem of interest is to study the convergence properties of simple Herglotz functions where the generating measures are given by finite B-spline expansions, and where the real part of the approximating functions are obtained via the Hilbert transform. In practice, such approximations are readily obtained as the solution to a finite- dimensional convex optimization problem. A constructive convergence proof is given in the case with linear B-splines, which is valid for all Lp-norms with 1 ≤ p ≤ ∞. A number of useful analytical expressions are provided regarding general B-splines and their Hilbert transforms. A typical physical application example is given regarding the passive approximation of a linear system having metamaterial characteristics. Finally, the flexibility of the optimization approach is illustrated with an example concerning the estimation of dielectric material parameters based on given dispersion data. 

Publisher
24 p.
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-63878 (URN)
Funder
Swedish Foundation for Strategic Research , AM13-0011
Available from: 2017-05-18 Created: 2017-05-18 Last updated: 2017-06-09Bibliographically approved

Open Access in DiVA

Licentiate Thesis (Full Text)(9320 kB)33 downloads
File information
File name FULLTEXT01.pdfFile size 9320 kBChecksum SHA-512
28edbc396ce69eceaebbed4e740fea1992a11ecf9f8cc49e6c800f7a86c238d5ae431713478859b6c685ad8e4379d5c02574145d28efc38833bc4ebda6c97d1d
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Ivanenko, Yevhen
By organisation
Department of Physics and Electrical Engineering
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 33 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 87 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf