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SweGRIDS research area CIPOWER Controllable Power Components
SweGRIDS project code CP26
Project type PhD
Status running
Researcher Sanja Duvnjak Zarkovic   (webpage)
University KTH (EME)
Project period 2017-02-01 to 2023 (delayed by periods of leave)   
Project supervisor Patrik Hilber   (webpage)
Industrial sponsors Vattenfall, Ellevio


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Project abstract

The importance of electricity in everyday life and demands to improve the reliability of distribution systems force utilities to operate and plan their networks in a more secure and economical manner. With higher demands on reliability from both customers and regulators, a big pressure has been put on the security of electricity supply that is considered as a fundamental requirement for modern societies. Thus, efficient solutions for reliability and security of supply improvements are not just of increasing interest, but also have significant socio-economic relevance. Distribution system planning (DSP) is one of the major activities of distribution utilities to deal with reliability enhancement.

The first part of the project (Licentiate degree) deals with developing optimization algorithms, which aim is to minimize customer interruption costs, and thus maximize the reliability of the system. This is implemented either by decreasing customer interruption duration, frequency of customer interruptions or both. The algorithms are applied on a single or multiple DSP problems. Mixed-integer programming has been used as an optimization approach. The idea behind the optimization is to achieve balance between reliability and the means to achieve this reliability. It is a decision making process, i.e. a trade-off between physical and pricing dimension of security of supply.

Afterwards, it is identified that in today’s power system, with innovation and technological development, but also new emerging treats, it is not enough anymore to present only certain reliability indices as performance indicators. There is a need for a comprehensive health index that will include not only reliability, but also different aspects of physical dimension of security of supply, such as resilience, power quality, stability, assets’ conditions, etc.

Thus, the idea of the second part of the project is to define power system health and give a comprehensive overview of all relevant concepts that can help in defining power system health. Furthermore, the ideas of creating a system health index and health plan algorithm need to be elaborated and certain framework needs to be established. The analyses of the outage statistics in Swedish power system between over certain period of time will be performed, in order to emphasize the importance of data analysis in creating a global view on power system health. Moreover, this analysis will help in identifying weak points in the system and creating a framework for improving power system health.

The idea of the health plan algorithm is to be applicable on different systems and subsystems. A good approach is to focus on smaller system and gather data that would capture deep knowledge about that specific system and specific event that affects the system. Moreover, by aggregating this algorithm on different systems, an overall view of power system health could be obtained. This would be beneficial not only for energy companies, but also for authorities and most importantly for customers and end-users.


Summary of work

2017. Literature review study finalized with the paper ”On the Security of Electricity Supply in Power Distribution Systems”.

2018. Recently finished conference paper “MILP vs. GA: Reliability improvement of radial distribution system through distribution system planning”, that compares two different optimization methods applied to the same distribution system planning problem. Working on the journal paper “Reliability improvement of radial distribution network through combination of network expansion planning and optimal switch placement”. By this time, almost all courses finalized (71/75 ECTS).

2019. Acceptance of the paper “MILP vs. GA: Reliability improvement of radial distribution system through distribution system planning” at PowerTech in Milano. All courses finished (78.5/75 ECTS).

Parental leave July 2019 – March 2020

2020. Licentiate thesis defended in October 2020. Three journal papers are submitted and currently under revision process (all three are mentioned in Licentiate thesis and they deal with different aspects of reliability centered distribution system planning). Supervised master thesis (A. Karlsson, “Guidelines for implementing monitoring and remote control equipment in an urban distribution network”). Currently working on the paper (CIRED conference 2021) that is based on this MSc thesis (follow-up).

2021. 80% PhD completion seminar presented in October 2021. Two journal papers accepted and published, two conference papers accepted and presented at the conferences. Paper "Defining power system health - process towards a system health index" finalized and submitted to a journal, currently under review process. Currently working on a conference paper that deals with adverse weather conditions that affect Swedish power system.


Event log

2017. KTH-EES Program of Excellence award

2018. Attendance and oral presentation at IEEE International Conference on Probabilistic Methods Applied to Power Systems (PMAPS), Boise, US (24th – 28th June 2018); work presented "On the Security of Electricity Supply in Power Distribution Systems"

2019. Presentation of paper “MILP vs. GA: Reliability improvement of radial distribution system through distribution system planning” at IEEE PES Conference PowerTech, Milano, Italy (23rd – 27th June 2019)

2020. Defense of Licentiate thesis “Security of electricity supply in power distribution system – Optimization algorithms for reliability centered distribution system planning” (20th October 2020)

2021. 80% PhD completion seminar finalized (7th October 2021). Attended CIRED 2021 and ICAE2021 virtual conferences and presented papers (September and November 2021).


Project reference-group

Erik Lejerskog,  Ellevio
Susanne Stjernfeldt,  Energiforsk
Fredrik Carlsson,  Vattenfall
Anna Lilly Brodersson,  Vattenfall
Robert Saers,  ABB CRC
Nilanga Abeywickrama,  ABB CRC
Malin Wihlén,  Ellevio
Claes Ahlrot,  E.ON
Tommie Lindquist,  Svenska kraftnät
Milan Radosavljevic,  Svenska kraftnät
Matz Tapper,  Svensk Energi
Lars Enarsson,  Ellevio
Tor Laneryd,  ABB CRC
Åsa Elmqvist,  Vindforsk/Energiforsk
Ola Ivarsson,  E.ON
Ying He,  Vattenfall
Kitimbo Andrew,  Vattenfall
Erik Jenelius,  KTH
Thomas Welte,  Sintef
Johan Öckerman,  Vattenfall Distribution
Ebrahim Shayesteh,  Vattenfall


Publications by this researcher

See alternatively the researcher's full DiVA list of publications, with options for sorting.
Publications in journals and conferences usually will not show until a while after they are published.

Onshore wind farm - Reliability centered cable routing
Sanja Duvnjak Zarkovic,   Ebrahim Shayesteh,   Patrik Hilber.
2021,   Electric power systems research, vol. 196

Integrated reliability centered distribution system planning — Cable routing and switch placement
Sanja Duvnjak Zarkovic,   Ebrahim Shayesteh,   Patrik Hilber.
2021,   Energy Reports, vol. 7

Security of Electricity Supply in Power Distribution System : Optimization Algorithms for Reliability Centered Distribution System Planning
Sanja Duvnjak Zarkovic.
2020,   Thesis (Licentiate), KTH Royal Institute of Technology, TRITA-EECS-AVL 2020:47

Impact of the fault location methods on SAIDI of a resonant-earthed distribution system
Md Zakaria Habib,   Md Tanbhir Hoq,   Sanja Duvnjak Zarkovic,   Nathaniel Taylor.
2020,   2020 IEEE International Conference on Power Systems Technology, POWERCON 2020, 14 September 2020 through 16 September 2020

Reliability improvement of distribution system through distribution system planning: MILP vs. GA
Sanja Duvnjak Zarkovic,   Stefan Stankovic,   Ebrahim Shayesteh,   Patrik Hilber.
2019,   2019 IEEE Milan PowerTech

On the Security of Electricity Supply in Power Distribution Systems
Sanja Duvnjak Zarkovic,   Patrik Hilber,   Ebrahim Shayesteh.
2018,   2018 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2018

Publication list last updated from DiVA on 2022-04-16 02:35.


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Page started: 2017-02-01
Last generated: 2022-04-16