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

Direct link
Tuning primary frequency controllers using robust control theory in a power system dominated by hydropower
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. (Hydropower)
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. (Hydropower)
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. (Hydropower)
2016 (English)Conference paper (Refereed)
Abstract [en]

A deterioration of the grid frequency quality has been observed in the Nordic synchronous system, and an oscillation with period 40-90 seconds is often clearly visible in the frequency deviation. A working group, consisting of e.g. transmission system operators and power producers, has been initiated to improve and harmonise the technical requirements for primary frequency control in the Nordic countries. In this paper, a method to optimise the tuning of hydropower governors providing primary frequency control to the system is suggested. A model of the Nordic power system is set up, nominal values of the system parameters and their typical ranges of variation are presented, and a controller structure is defined. The objectives of primary frequency control are discussed and interpreted as requirements on the gain of the closed loop transfer functions of the system. These requirements are then used to define tuning goals for an optimisation of the controller parameters. The optimisation is carried out as a weighted minimisation of the closed loop system transfer functions in frequency domain. The result is evaluated in frequency domain and by time domain simulations of a system with added actuator non-linearities. The sensitivity to system parameter variation is analysed in terms of the performance of the optimised controllers in a system with changing parameters, but also in terms of how the optimisation result changes if the nominal system parameters are changed. The results show that compared to the governor tuning currently used in many hydropower plants in the system, retuned governors could reduce the amplitude of the 40-90 second oscillation considerably. A small, floating deadband on the controller output signal is discussed as a means to reduce the number of small movements in the actuators and turbines. The advantage of the presented method is that many different aspects and requirements on primary frequency control are taken into account and the trade-off between different aspects of the performance is visualised and can be controlled directly.

Place, publisher, year, edition, pages
2016.
Keyword [en]
frequency control, power system stability, governor, PID tuning, robust control, primary control
National Category
Engineering and Technology Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Science with specialization in Science of Electricity
Identifiers
URN: urn:nbn:se:uu:diva-308436OAI: oai:DiVA.org:uu-308436DiVA: diva2:1049861
Conference
CIGRE Session 2016
Available from: 2016-11-25 Created: 2016-11-25 Last updated: 2016-11-30
In thesis
1.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Saarinen, LinnNorrlund, PerLundin, Urban
By organisation
Electricity
Engineering and TechnologyElectrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

Total: 4 hits
ReferencesLink to record
Permanent link

Direct link