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HILP - Analysis of extraordinary events in power systems

HILP - Analysis of extraordinary events in power systems

Society is crucially dependent on an adequate level of security of electricity supply. This imposes requirements for the planning and operation of modern power systems.

The complexity and uncertainties of the power system are increasing, due to integration of distributed renewable power generation, the introduction of new technologies (smartgrids), more extreme weather and stronger integration between the Nordic and European power systems. This development imposes risks and vulnerabilities in the power system needing to be dealt with. In particular, extraordinary events are of special interest as they imply substantial consequences to society. The mechanisms behind these events are not well understood today, and there is a need to increase the ability to identify, understand and assess extraordinary events.

By building on today's best methods and theories, methods and tools for analysing extraordinary events in power systems will be developed. The main challenges to be addressed are the identification of causes and underlying mechanisms, quantification of the consequences and handling uncertainties. The use of case studies of the Nordic power transmission system will ensure the applicability of methods.

The project results provide decision support to make a best possible trade-off between security of supply and societal costs in planning and operation of the Nordic power system. The project build new competence for analysis of extraordinary events, and the collaboration with transmission system operators and authorities ensures that the developed methodologies increase situational awareness as well as aid for deciding on remedial actions and preparedness plans for the power system. Improved understanding of the risks associated with extraordinary events will also be of great value for electric utilities, households and industry in general, as modern society is heavily dependent on a reliable electric supply.


Sperstad, I. B.; Kjølle, G. H.; Gjerde, O.:  A Comprehensive Framework for Vulnerability Analysis of Extraordinary Events in Power Systems. Reliability Engineering & System Safety, Vol. 196, April 2020.

Kiel, E. S.; Kjølle, G. H.:  The impact of protection system failures and weather exposure on power system reliability. IEEE International Conference on Environment and Electrical Engineering, June 2019, Genova, Italy.

Solvang, E. H.; Sperstad, I. B.; Jakobsen, S. H.; Uhlen, K.: Dynamic simulation of simultaneous HVDC contingencies relevant for vulnerability assessment of the nordic power systemIEEE Milan PowerTech, June 2019, Milan, Italy.

Kiel, E. S.; Kjølle, G. H.: Transmission line unavailability due to correlated threat exposureIEEE Milan PowerTech, Milan, Italy, June 2019.

Kiel, E. S.; Kjølle, G. H.: Identification, visualization and reduction of risk related to HILP events in power systems54th International Universities Power Engineering Conference (UPEC), Sept. 2019, Bucharest, Romania.

Sperstad, I. B.; Kiel, E. S.: Development of a Qualitative Framework for Analysing High-Impact Low-Probability Events in Power Systems. European Safety & Reliability Conference (ESREL), 2018, Trondheim, Norway.

Sperstad, I. B.: Identifying high-impact operating states in power system reliability analysis. Probabilistic Methods Applied to Power Systems (PMAPS), 2018, IEEE International Conference on, Boise, ID, USA, IEEE.

Sperstad, I. B.; Kjølle, G. H.; Gjerde, O.; Vrana, T. K.; Jakobsen, S. H.; Turunen, J.; Haarla, L. (2018). Vulnerability Analysis of HVDC Contingencies in the Nordic Power SystemSINTEFblog. Report no. C2-132, CIGRE Session, 2018, Paris, France.

Solheim, Ø.R.; Trötscher, T.; Kjølle, G. H.: Wind Dependent Failure Rates for Overhead Transmission Lines Using Reanalysis Data and a Bayesian Updating Scheme. International Conference on Probabilistic Methods Applied to Power Systems (PMAPS), Oct. 2016, Beijing, China.


Published 18 August 2016

Project duration

2016 - 2019