Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Studies of high-temperature superconducting tapes and their application in power apparatus
KTH, School of Electrical Engineering (EES).
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Intensive development in the field of high-temperature superconductors (HTS) has resulted in long length HTS with high current carrying capacity. The performance of HTS in the form of multifilamentary silver sheathed Bi-2223 tapes is close to the requirements for power application. Several power apparatus prototypes based on HTS have been and are being demonstrated. Recently the first commercial order for a HTS power apparatus was placed. Tennessee Valley Authority ordered two 12 MVA synchronous condensers with HTS rotor windings for reactive power compensation.

In most power devices the conductor is carrying an AC transport current while it is exposed to an AC magnetic field transverse to the current path. In certain applications such as multi-layer power transmission cables or the control winding in a controllable reactor, the conductors are exposed to a magnetic field component longitudinal to the tape axis that is parallel with the current path. In this thesis, the losses in HTS tapes in longitudinally applied magnetic field are investigated and a single phase small scale controllable reactor with a loss optimized HTS control winding is designed, constructed and tested.

An experimental setup to measure the losses in tapes exposed to longitudinal magnetic fields, transport currents, frequencies, and temperatures is presented. The system is based on a calorimetric loss measuring method where the losses are determined by the temperature response of the conductor when exposed to magnetic field and/or carrying transport current.

Semi-empirical loss models are developed from the results of the loss measurements of non-twisted multifilamentary Bi-2223 tapes. The losses when the sample is carrying transport currents and is exposed to longitudinal magnetic fields are found to consist of hysteresis, flux flow, and eddy current losses. The hysteresis losses can be modeled with the critical state model. The flux flow losses can be described with a power law dependent current voltage characteristic.

The loss models are well suited for the design of power devices in which HTS is exposed to longitudinal magnetic fields. Based on the knowledge of the losses a single phase small scale controllable reactor with a loss optimized HTS control winding is designed, constructed and tested. A simple model of the magnetic circuit of the controllable reactor is presented. Calculations from the model are compared with experimental measurements. The feasibility to design controllable shunt reactors with large linear dynamic range, low losses and limited harmonic distortion is demonstrated. Compared to a copper control winding the HTS control winding increases the dynamic range and reduces the size due to the high current density and reduces the losses of the control winding.

Place, publisher, year, edition, pages
Stockholm: KTH , 2006. , xi, 73 p.
Series
Trita-EE, ISSN 1653-5146 ; 2006:038
Keyword [en]
electrocity physics, magnetism, electronics engineering, electrical engineering
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-4112ISBN: 91-7178-439-X (print)OAI: oai:DiVA.org:kth-4112DiVA: diva2:10793
Public defence
2006-10-03, Fal F3, 00:00
Opponent
Supervisors
Note

QC 20100927

Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2013-01-22Bibliographically approved
List of papers
1. Impact of DC components in transport current and external magnetic field on hysteresis losses in an HTS tape
Open this publication in new window or tab >>Impact of DC components in transport current and external magnetic field on hysteresis losses in an HTS tape
2004 (English)In: IEEE transactions on applied superconductivity (Print), ISSN 1051-8223, Vol. 14, no 3, 1955-1958 p.Article in journal (Refereed) Published
Abstract [en]

The high-temperature superconductor (HTS) development is presently intensive, and one can expect that HTSs will be used in different electric devices in the future. In some of these devices, e.g., a magnetostrictive actuator, the conductor will be exposed to both ac and dc transport currents and external magnetic fields. One of the most important parameters in the design of electric devices is the power loss. It is, therefore, of importance to develop models that are able to predict the power loss in devices based on HTSs. In this paper, we present an experimental characterization of the hysteresis losses in an HTS tape exposed to ac or dc transport currents in combination with external magnetic fields. The experimental results are compared to some existing models based on the critical state model. The power loss was measured on a multifilamentary Bi-2223 tape at constant temperature (70 K) and frequency (50 Hz).

Keyword
AC, Calorimetric measurements, DC, High-temperature superconductor, Hysteresis losses, Models
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6156 (URN)10.1109/TASC.2004.830604 (DOI)000223724800003 ()2-s2.0-4544383315 (Scopus ID)
Note
QC 20100917Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2011-09-23Bibliographically approved
2. Experimental set-up for calorimetric AC loss measurements on HTS tapes in applied longitudinal magnetic fields carrying transport currents at variable temperatures
Open this publication in new window or tab >>Experimental set-up for calorimetric AC loss measurements on HTS tapes in applied longitudinal magnetic fields carrying transport currents at variable temperatures
2004 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 75, no 1, 99-103 p.Article in journal (Refereed) Published
Abstract [en]

In most power devices, the conductor is carrying an ac transport current while it is exposed to an ac magnetic field transverse to the current path. In certain applications, such as multilayer power cables or the control winding in a controllable reactor, the conductors are exposed to a magnetic field component parallel with the current path that is longitudinal to the tape axis. An experimental setup to measure the losses at a different longitudinal magnetic field, transport currents, frequency, and temperature is presented. The system is based on a calorimetric measuring method. Examples are given of power loss measurements on multifilamentary Bi 2223 tapes at different longitudinal ac magnetic fields 0-250 mT peak value, frequencies 0-1000 Hz, ac transport currents 0-70 A peak value, and temperatures 55-85 K. The calorimetric technique presented is fast, accurate, and capable of measuring losses between 0.5-100 mW/m. The data obtained from the apparatus can provide an improved base for the design of power devices.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6157 (URN)10.1063/1.1633002 (DOI)000187536500016 ()2-s2.0-0942267674 (Scopus ID)
Note
QC 20100927 QC 20111031Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2011-10-31Bibliographically approved
3. AC losses in applied longitudinal magnetic fields at variable temperatures
Open this publication in new window or tab >>AC losses in applied longitudinal magnetic fields at variable temperatures
2004 (English)In: IEEE transactions on applied superconductivity (Print), ISSN 1051-8223, Vol. 14, no 1, 22-27 p.Article in journal (Refereed) Published
Abstract [en]

In most power devices, the conductor is carrying anac transport current while it is exposed to an ac magnetic fieldtransverse to the current path. In certain applications, such aspower cables or a control winding in a controllable reactor, theconductors are exposed to a magnetic field component longitudinalto the tape axis that is parallel to the current path. To createan improved base for the design of such power devices it is ofinterest to study the losses in high-temperature superconductortapes due to longitudinal field in detail. We have investigated thelosses at several temperatures of a nontwisted multifilamentaryBi-2223 tape when it was exposed to a longitudinal magnetic field.The losses were measured with a calorimetric method and theresults were compared with the critical state hysteresis loss model.The hysteresis losses are dominating at power frequencies (50,60 Hz) in the investigated field range 2–200 mT and are accuratelydescribed by the critical state hysteresis model.

Keyword
AC losses, high-temperature superconductor (HTS) tape, longitudinal magnetic field.
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-6158 (URN)10.1109/TASC.2004.825389 (DOI)000220946300004 ()2-s2.0-2442688115 (Scopus ID)
Note
QC 20100927Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2011-10-31Bibliographically approved
4. Losses in HTS tapes carrying DC transport currents exposed to an AC magnetic field parallel with the current
Open this publication in new window or tab >>Losses in HTS tapes carrying DC transport currents exposed to an AC magnetic field parallel with the current
2003 (English)In: Proceedings of the6th European Conference on Applied Superconductivity, Sorrento, Italy, 14-18 September 2003., 2003, Vol. 118, 2005-2012 p.Conference paper, Published paper (Refereed)
Series
Institute of Physics Conference Series, 181
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6159 (URN)
Note
QC 20100927Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2010-09-27Bibliographically approved
5. The design and construction of a controllable reactor with a HTS control winding.
Open this publication in new window or tab >>The design and construction of a controllable reactor with a HTS control winding.
2006 (English)In: 7TH EUROPEAN CONFERENCE ON APPLIED SUPERCONDUCTIVITY (EUCAS'05), 2006, 873-876 p.Conference paper, Published paper (Refereed)
Abstract [en]

Reactive power compensation is vital for obtaining efficient operation of long transmission power lines or cables. The need of reactive power changes with the load of the transmission line. Discrete units of conventional reactors are therefore switched in and out in order to obtain more efficient reactive power compensation. A continuous reactive compensation will reduce the transmission losses and increase the transmission capacity of active power. We have designed and constructed a one phase small scale prototype of a controllable shunt reactor with a high temperature superconducting control winding. The reactor consists basically of two windings and an iron core. The control winding is placed so that it generates a DC magnetic field perpendicular to the main AC magnetic field. Thus the DC current in the control winding can control the direction of the magnetization of the iron core and thereby the reactance of the reactor. Such a control winding will have low losses and give the reactor a large dynamic range. For this small scale reactor we found that the reactive power could be varied with a factor six. We have demonstrated the feasibility to design large scale controllable shunt reactors with large dynamic range and low losses utilizing a control winding made of a high temperature superconductor.

Series
Journal of Physics Conference Series, ISSN 1742-6588 ; 43
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6162 (URN)10.1088/1742-6596/43/1/213 (DOI)000277479400213 ()2-s2.0-33746288643 (Scopus ID)
Conference
7th European Conference on Applied Superconductivity Vienna Univ Technol, Vienna, AUSTRIA, SEP 11-15, 2005
Note
Uppdaterad från submitted till published: 20100927. Tidigare titel: The design of a HTS control winding of a controllable reactor QC 20100927Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2010-09-27Bibliographically approved
6. The magnetic circuit of a controllable reactor
Open this publication in new window or tab >>The magnetic circuit of a controllable reactor
2006 (English)In: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 42, no 9, 2196-2200 p.Article in journal (Refereed) Published
Abstract [en]

Reactive power compensation is vital for obtaining efficient operation of long transmission power lines or cables. A controllable shunt reactor that controls the transmission of power by continuous reactive power compensation will reduce the transmission losses and increase the transmission capacity of active power. We show that the saturation phenomena of iron and the high current density of a high-temperature superconductor can be utilized to design controllable reactors with large dynamic range, low losses, and limited harmonic distortion. We have designed and constructed a small-scale prototype of a controllable shunt reactor with a high-temperature superconductor control winding. We present a simple model of the magnetic circuit of the controllable reactor and we compare alculations from the model to experimental measurements on the controllable reactor.

Keyword
high-temperature superconductors, magnetic core, reactive power control, saturable core
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6161 (URN)10.1109/TMAG.2006.878307 (DOI)000240009000011 ()2-s2.0-33748314729 (Scopus ID)
Note
QC 20100927Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2010-09-27Bibliographically approved
7. The design and construction of a controllable reactor with a HTS control winding.
Open this publication in new window or tab >>The design and construction of a controllable reactor with a HTS control winding.
2006 (English)In: 7TH EUROPEAN CONFERENCE ON APPLIED SUPERCONDUCTIVITY (EUCAS'05), 2006, 873-876 p.Conference paper, Published paper (Refereed)
Abstract [en]

Reactive power compensation is vital for obtaining efficient operation of long transmission power lines or cables. The need of reactive power changes with the load of the transmission line. Discrete units of conventional reactors are therefore switched in and out in order to obtain more efficient reactive power compensation. A continuous reactive compensation will reduce the transmission losses and increase the transmission capacity of active power. We have designed and constructed a one phase small scale prototype of a controllable shunt reactor with a high temperature superconducting control winding. The reactor consists basically of two windings and an iron core. The control winding is placed so that it generates a DC magnetic field perpendicular to the main AC magnetic field. Thus the DC current in the control winding can control the direction of the magnetization of the iron core and thereby the reactance of the reactor. Such a control winding will have low losses and give the reactor a large dynamic range. For this small scale reactor we found that the reactive power could be varied with a factor six. We have demonstrated the feasibility to design large scale controllable shunt reactors with large dynamic range and low losses utilizing a control winding made of a high temperature superconductor.

Series
Journal of Physics Conference Series, ISSN 1742-6588 ; 43
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-6162 (URN)10.1088/1742-6596/43/1/213 (DOI)000277479400213 ()2-s2.0-33746288643 (Scopus ID)
Conference
7th European Conference on Applied Superconductivity Vienna Univ Technol, Vienna, AUSTRIA, SEP 11-15, 2005
Note
Uppdaterad från submitted till published: 20100927. Tidigare titel: The design of a HTS control winding of a controllable reactor QC 20100927Available from: 2006-09-22 Created: 2006-09-22 Last updated: 2010-09-27Bibliographically approved

Open Access in DiVA

fulltext(2287 kB)1535 downloads
File information
File name FULLTEXT01.pdfFile size 2287 kBChecksum MD5
aaba84c76ba4337997862542bb5cf437ee7eeb63c98266f44826fe3b0fc15bd14769f748
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Wass, Torbjörn
By organisation
School of Electrical Engineering (EES)
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1535 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

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 565 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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