Change search
Link to record
Permanent link

Direct link
Publications (6 of 6) Show all publications
Nilsson, F., Moyassari, A., Bautista, A., Castro, A., Arbeloa, I., Järn, M., . . . Johansson, K. (2019). Modelling anti-icing of railway overhead catenary wires by resistive heating. International Journal of Heat and Mass Transfer, 143, Article ID 118505.
Open this publication in new window or tab >>Modelling anti-icing of railway overhead catenary wires by resistive heating
Show others...
2019 (English)In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 143, article id 118505Article in journal (Refereed) Published
Abstract [en]

Aggregation of ice on electrical cables and apparatus can cause severe equipment malfunction and is thus considered as a serious problem, especially in arctic climate zones. In particular, cable damage caused by ice accumulation on railway catenary wires is in wintertime a common origin for delayed trains in the northern parts of Europe. This study examines how resistive heating can be used for preventing formation of ice on metallic, non-insulated electrical cables. The heat equation and the Navier Stokes equations were solved simultaneously with FEM in 3D in order to predict the cable temperature as function of external temperature, applied voltage, wind speed, wind direction, and heating time. An analytical expression for the heat transfer coefficient was derived from the FEM simulations and it was concluded that the influence of wind direction can typically be neglected. Experimental validation measurements were performed on Kanthal cables in a climate chamber, giving temperature increase results in good agreement with the simulation predictions. The resistive heating efficiency, i.e. the ratio between applied electrical energy and resulting thermal energy, was found to be approximately 68% in this particular study.

Place, publisher, year, edition, pages
Elsevier Ltd, 2019
Keywords
FEM, Ice-prevention, Kanthal, Railway overhead lines, Resistive heating
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39790 (URN)10.1016/j.ijheatmasstransfer.2019.118505 (DOI)2-s2.0-85070233997 (Scopus ID)
Note

Funding text 1: The SP Technical Institute of Sweden is gratefully acknowledged for financial support as part of the Eurostars-funded project IceControl. Appendix A Zsolt et al [40] developed a model for predicting the current I needed to prevent ice accretion of electrical overhead lines by resistive heating. In this case the factors in the heat-balance are q j (resistive joule heating), q c (heat loss due to convection), q f (heat flow rate due to stagnation and friction in the boundary layer), q e (heat loss due to evaporation) and q w (heat loss due to impinging droplets [63–66] : (A1) q j = q c - q f + q e + q w (A2) q j = R I 2 L (A3) q c = h ( T - T ref ) 2 π r ∼ L (A4) q f = 0.79 · 2 π r ∼ L · h v 2 / ( 2 c p ) (A5) q e = 0.622 h l e · π r ∼ L · ( p s - p a ) / c p p (A6) q w = κ 1 κ 2 W v E · 2 r L c w ( T - T 0 ) The parameters used in A1-A6 are: resistance (per meter) R , current I , cable length L , heat transfer coefficient h , cable surface temperature T , atmosphere temperature T 0 , effective cable radius r ∼ , wind speed v , specific heat c p , latent heat of evaporation l e , saturation vapour pressure at cable surface p s and in atmosphere p a , atmospheric pressure p , correction factors κ 1 and κ 2 , liquid water content W , collection efficiency E , cable radius r, and specific heat of liquid water c w . When Eqs. A1-A7 are combined, they can be used to calculate the current needed to prevent ice accretion: (A7) I = 2 π r ∼ R h ( T - T 0 ) - 0.79 h v 2 2 c p + 0.622 h l e ( p s - p a ) 2 c p p + r κ 1 κ 2 E W v c w ( T - T 0 ) r ∼ π 0.5

Available from: 2019-08-19 Created: 2019-08-19 Last updated: 2023-05-25Bibliographically approved
Zucca, M., Loader, B., Schmidt, M., Welinder, J., Tammi, K., Bruna Romero, J., . . . Kuster, N. (2018). The Project 'Metrology for Inductive Charging of Electric Vehicles'. In: CPEM 2018 - Conference on Precision Electromagnetic Measurements: . Paper presented at 2018 Conference on Precision Electromagnetic Measurements, CPEM 2018, 8 July 2018 through 13 July 2018.
Open this publication in new window or tab >>The Project 'Metrology for Inductive Charging of Electric Vehicles'
Show others...
2018 (English)In: CPEM 2018 - Conference on Precision Electromagnetic Measurements, 2018Conference paper, Published paper (Refereed)
Abstract [en]

The European metrology programme for innovation and research (EMPIR) is the current main programme for European research on metrology. In 2016, within the EMPIR call, the project 'Metrology for inductive charging of electric vehicles' (MICEV) was approved and it started in September 2017. Inductive charging is a wireless charging technology that will be widely used with electric vehicles (EVs) in the near future, offering many advantages over traditionally fuelled and current EVs. The project aims to advance inductive power transfer (IPT) for EV charging by developing metrology techniques for measuring power transfer efficiency and reliable demonstration of compliance with existing safety standards for human exposure. The main research topics are: measurement of the power transmitted on-board, transmission efficiency, requirements for measurements in the dynamic charging, assessment of magnetic field exposure.

Keywords
Electromagnetic measurements, electromagnetic modeling, measurement techniques, metrology, power measurement, uncertainty, Charging (batteries), Computational electromagnetics, Efficiency, Electric power measurement, Electric vehicles, Energy transfer, Inductive power transmission, Measurement, Regulatory compliance, Electric Vehicles (EVs), Electromagnetic measurement, Inductive power transfers (IPT), Power transfer efficiency, Transmission efficiency, Uncertainty analysis
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36604 (URN)10.1109/CPEM.2018.8501202 (DOI)2-s2.0-85056997423 (Scopus ID)9781538609736 (ISBN)
Conference
2018 Conference on Precision Electromagnetic Measurements, CPEM 2018, 8 July 2018 through 13 July 2018
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2018-12-17Bibliographically approved
Karlsson, S., Österlund, L., Niklasson, G., Granqvist, C.-G., Järn, M., Eriksson, J., . . . Ludvigsson, M. (2018). “Transparent Intelligence” for Sustainable Development. In: : . Paper presented at 15th International Conference on the Physics of Non-Crystalline Solids (PNCS) and European Society of Glass Science and Technology Conference (ESG, Saint Malo, France.
Open this publication in new window or tab >>“Transparent Intelligence” for Sustainable Development
Show others...
2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Transparent materials are essential in everyone’s life. They enable daylight to reach the interior of buildings, thereby contributing to both our physical and mental well-being; they are the primary component for communication via optical fibers and a key component in electronic devices such as protective cover and/or dielectric material; and they enable clean energy production through solar panels or algae reactors by acting as protective and light transmitting barriers. Adding functions to transparent materials in an intelligent way creates further opportunities to use and enhance the beneficial impacts of transparency. The concept Transparent Intelligence covers transparent materials and products with integral intelligent functions – passive, active or interactive. By using Transparent Intelligence it is possible to embrace many of the societal challenges that we are facing today. The concept can be divided into five broad industrial sectors: Built Environment, Information and Communication Technologies (ICT), Solar Energy, Mobility, and Materials. A perspective on how Transparent Intelligence can improve the sustainable development of our world will be presented, using examples of electrochromic windows for energy-efficient buildings, photocatalytic coatings for improved indoor air quality, transparent conductive coatings for antennas, bandpass filters for mobile phone indoor coverage, UV down-converting components for efficient solar energy, hygienic surfaces for infection mitigation on electronic devices, printed electronics for sustainable glass packaging, and IR-reflecting coatings for fire safety.

National Category
Materials Engineering
Identifiers
urn:nbn:se:ri:diva-34106 (URN)
Conference
15th International Conference on the Physics of Non-Crystalline Solids (PNCS) and European Society of Glass Science and Technology Conference (ESG, Saint Malo, France
Projects
Smart Housing Småland
Funder
Vinnova, 2016-04218
Note

Funding: Vinnova 2016-04218

Available from: 2018-07-11 Created: 2018-07-11 Last updated: 2023-05-25Bibliographically approved
Karlsson, S., Järn, M., Welinder, J., Andersson, A., Liinanki, M. & Försth, M. (2017). Transparent intelligens för en bättre värld - en sammanfattning av fyra år med TIME. GLAS (2), 58-59
Open this publication in new window or tab >>Transparent intelligens för en bättre värld - en sammanfattning av fyra år med TIME
Show others...
2017 (Swedish)In: GLAS, no 2, p. 58-59Article in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
Stockholm: Glastjänster för GBF AB, 2017
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:ri:diva-29886 (URN)
Available from: 2017-06-13 Created: 2017-06-13 Last updated: 2023-05-25Bibliographically approved
Ödman, T., Welinder, J., Andersson, N., Otterskog, M., Lindén, M., Ödman, N. & Larsson, C. U. (2015). A study of different fabrics to increase radar cross section of humans. In: Stud. Health Technol. Informatics: . Paper presented at 2 June 2015 through 4 June 2015 (pp. 201-206). IOS Press, 211
Open this publication in new window or tab >>A study of different fabrics to increase radar cross section of humans
Show others...
2015 (English)In: Stud. Health Technol. Informatics, IOS Press , 2015, Vol. 211, p. 201-206Conference paper, Published paper (Refereed)
Abstract [en]

This purpose of the study was to increase the visibility on radar for unprotected pedestrians with the aid of conducting fabric. The experiment comprised measurements of four types of fabric to determine the radio frequency properties, such as radar cross section (RCS) for the vehicle radar frequency 77 GHz and transmission (shielding) in the frequency range 3-18 GHz. Two different thicknesses of polypyrrole (PPy) nonvowen fabric were tested and one thickness for 30 % and 40 % stainless steel fabrics respectively. A jacket with the thinner nonvowen material and one with 40 % steel were tested and compared to an unmodified jacket in the RCS measurement. The measurement showed an increase in RCS of 4 dB for the jacket with the 40 % steel lining compared to the unmodified jacket. The transmission measurement was aimed at determining the fabric with the highest transmission of an incoming radio wave. The 30 % steel fabric and the two thicknesses of the nonvowen fabrics were tested. One practical application is for example the use of radar reflective material in search and rescue (SAR) clothes. The study showed that the 30 % steel fabric was the best candidate for further RCS measurements. © 2015 The authors and IOS Press. All rights reserved.

Place, publisher, year, edition, pages
IOS Press, 2015
Keywords
Conductive fabric, Polypyrrole fabric, Radar cross section, RCS, SAR, Nanotechnology, Polypyrroles, Radar measurement, Radar shielding, Radio transmission, Radio waves, Steel testing, Synthetic aperture radar, Vehicle transmissions, Wearable technology, Conductive fabrics, Radar cross sections (RCS), Radar frequencies, Radio-frequency properties, Reflective materials, Search and rescue, Stainless steel fabrics, Transmission measurements, polymer, polypyrrole, pyrrole derivative, stainless steel, biomedical technology assessment, equipment design, human, telecommunication, textile, Humans, Polymers, Pyrroles, Radar, Technology Assessment, Biomedical, Textiles
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-43161 (URN)10.3233/978-1-61499-516-6-201 (DOI)2-s2.0-84939244723 (Scopus ID)9781614995159 (ISBN)
Conference
2 June 2015 through 4 June 2015
Available from: 2020-01-29 Created: 2020-01-29 Last updated: 2020-12-01Bibliographically approved
Lundgren, U., Welinder, J. & Carlsson, J. (2013). Analysis of electrical appliance power supplies and a potential impact on the electrical grid stability. In: IEEE International Symposium on Electromagnetic Compatibility: . Paper presented at 2013 International Symposium on Electromagnetic Compatibility, EMC Europe 2013, 2 September 2013 through 6 September 2013, Brugge (pp. 688-692). , Article ID 6653389.
Open this publication in new window or tab >>Analysis of electrical appliance power supplies and a potential impact on the electrical grid stability
2013 (English)In: IEEE International Symposium on Electromagnetic Compatibility, 2013, p. 688-692, article id 6653389Conference paper, Published paper (Refereed)
Abstract [en]

This paper considers an increasing problem in the consumer end of the electrical grid. The ongoing change from constant impedance loads towards constant power characteristics in new household electrical appliances may affect the network voltage stability. Can the smart grid development disarm this potential threat? This work points out an important target for load modeling in network simulation.

Keywords
Energy efficiency, Load model, Smart grid, Switched mode power supply, Voltage stability, Electrical appliances, Electrical grids, Household electrical appliances, Load modeling, Ongoing changes, Potential impacts, Potential threats, Electromagnetic compatibility, Smart power grids, Switched mode power supplies, Voltage control, Voltage stabilizing circuits, Computer simulation
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-48613 (URN)2-s2.0-84890591939 (Scopus ID)9781467349796 (ISBN)
Conference
2013 International Symposium on Electromagnetic Compatibility, EMC Europe 2013, 2 September 2013 through 6 September 2013, Brugge
Available from: 2020-10-05 Created: 2020-10-05 Last updated: 2020-12-01Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6274-3158

Search in DiVA

Show all publications