uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
Critical Speed Control for a Fixed Blade Variable Speed Wind Turbine
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.ORCID iD: 0000-0001-5467-4527
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.ORCID iD: 0000-0002-6975-1588
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.ORCID iD: 0000-0001-8598-2565
2017 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 11, 1699Article in journal (Refereed) Published
Abstract [en]

A critical speed controller for avoiding a certain rotational speed is presented. The controller is useful for variable speed wind turbines with a natural frequency in the operating range. The controller has been simulated, implemented and tested on an open site 12 kW vertical axis wind turbine prototype. The controller is based on an adaptation of the optimum torque control. Two lookup tables and a simple state machine provide the control logic of the controller. The controller requires low computational resources, and no wind speed measurement is needed. The results suggest that the controller is a feasible method for critical speed control. The skipping behavior can be adjusted using only two parameters. While tested on a vertical axis wind turbine, it may be used on any variable speed turbine with the control of generator power.

Place, publisher, year, edition, pages
2017. Vol. 10, no 11, 1699
Keyword [en]
vertical axis wind turbine, variable speed, control, optimal torque, critical speed, speed exclusion zone, natural frequencies, eigenfrequencies
National Category
Energy Systems
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
URN: urn:nbn:se:uu:diva-331782DOI: 10.3390/en10111699OAI: oai:DiVA.org:uu-331782DiVA: diva2:1150356
Funder
StandUpStandUp for Wind
Available from: 2017-10-18 Created: 2017-10-18 Last updated: 2017-10-26
In thesis
1. Electromechanics of Vertical Axis Wind Turbines
Open this publication in new window or tab >>Electromechanics of Vertical Axis Wind Turbines
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Wind power is an established mean of clean energy production and the modern horizontal axis wind turbine has become a common sight. The need for maintenance is high and future wind turbines may need to be improved to enable more remote and offshore locations. Vertical axis wind turbines have possible benefits, such as higher reliability, less noise and lower centre of gravity. This thesis focuses on electromechanical interaction in the straight bladed Darrieus rotor (H-rotor) concept studied at Uppsala University.

One of the challenges with vertical axis technology is the oscillating aerodynamic forces. A force measurement setup has been implemented to capture the forces on a three-bladed 12 kW open site prototype. The normal force showed good agreement with simulations. An aerodynamic torque could be estimated from the system. The total electrical torque in the generator was determined from electrical measurements. Both torque estimations lacked the expected aerodynamic ripple at three times per revolution. The even torque detected is an important result and more studies are required to confirm and understand it.

The force measurement was also used to study the loads on the turbine in parked conditions. It was discovered that there is a strong dependence on wind direction and that there is a positive torque on the turbine at stand still. The results can assist to determine the best parking strategies for an H-rotor turbine.

The studied concept also features diode rectification of the voltage from the permanent magnet synchronous generator. Diodes are considered a cheap and robust solution for rectification at the drawback of inducing ripple in the torque and output voltage. The propagation of the torque ripple was measured on the prototype and studied with simulations and analytical expressions. One key conclusion was that the mechanical driveline of the turbine is an effective filter of the diode induced torque ripple.

A critical speed controller was implemented on the prototype. The controller was based on optimal torque control and according to the experiments and the simulations it was able to avoid a rotational speed span. Finally, the optimal torque control was evaluated for multiple turbines with diode rectification to a common DC-link. The setup can potentially reduce the overall complexity of wind farms. The simulations suggest that stability of the system can be obtained by controlling the DC-link load as a semi constant voltage.

The thesis is based on nine papers of which six are treated in the thesis summary.

 

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. 81 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1581
Keyword
Wind power, Diode rectification, Control, Measurement, Simulation, Electromechanical coupling, vindkraft, diodlikriktning, reglering, mätning, simulering
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Energy Systems
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
urn:nbn:se:uu:diva-331844 (URN)978-91-513-0117-4 (ISBN)
Public defence
2017-12-08, Å2005, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, 09:15 (English)
Opponent
Supervisors
Funder
StandUpStandUp for Wind
Available from: 2017-11-14 Created: 2017-10-18 Last updated: 2017-11-14

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Rossander, MorganGoude, AndersEriksson, Sandra
By organisation
Electricity
In the same journal
Energies
Energy Systems

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 50 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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