Doctoral Thesis

Advanced Tools for Critical Infrastructure Analysis

Final Thesis 12.39 MB Summary of Thesis 12.39 MB

Author of thesis: Ing. Matěj Vrtal, Ph.D.

Acad. year: 2024/2025

Supervisor: prof. Ing. Petr Toman, Ph.D.

Reviewers: prof. Ing. Radomír Goňo, Ph.D., prof. Matti Lehtonen

Abstract:

This doctoral thesis focuses on advanced methods and tools for simulating and analyzing interdependent critical infrastructures, with a primary emphasis on the energy and data communication sectors. The motivation arises from the growing complexity and interconnectivity of urban infrastructures, which introduce new challenges related to reliability, unavailability, cascading failures, and maintenance planning. The proposed platform enables combined simulation of multiple infrastructure layers through a modular and scalable architecture, allowing future integration of additional systems such as water supply, transportation, or gas networks. A key contribution is the implementation of a structured simulation engine based on state matrix management, which enables detailed tracking and visualization of failure propagation and mutual dependencies across domains. Reliability analysis is supported by stochastic modeling techniques, including time-dependent unavailability evaluation using Weibull distributions and the simulation of corrective and preventive maintenance strategies. The platform includes a graphical user interface with map-based visualization, supporting intuitive scenario design and resilience assessment. A dedicated module for maintenance optimization was implemented, leveraging reliability metrics to identify cost-effective maintenance schedules. A novel synthetic test network combining power and data infrastructures was developed to evaluate the simulator’s capabilities and support reproducible research. The platform was validated using both anonymized real-world data and synthetic scenarios, and its performance and accuracy were benchmarked against existing open-source reliability tools. The presented research delivers a robust simulation and analysis framework for interdependent infrastructure systems and supports informed decision-making in the domains of energy and communication. It establishes a foundation for future developments in predictive maintenance, interdependency modeling, and resilience assessment in smart city environments.

Keywords:

Critical infrastructure, interdependency, simulation platform, smart grid, reliability analysis, unavailability modeling, maintenance optimization, cascading failures, communication network.

Date of defence

25.06.2025

Result of the defence

Defended (thesis was successfully defended)

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Process of defence

Defence of the thesis The defense took place in the presence of all committee members. During the defense, the doctoral student presented the results of his dissertation to the committee, including his own contributions. After the doctoral student's presentation, his supervisor informed the attendees about his evaluation of the entire course of study. This was followed by the presentation of the referees' reports and a discussion of the referees' questions and comments. Then, in the public discussion, questions and comments on the dissertation were presented by prof. Drapela, prof. Goňo, doc. Mašek. A written record of the questions is attached to the minutes. All questions raised by the opponents and in the public discussion were correctly addressed by the PhD student. The PhD student has demonstrated creative ability in the given research area, and the thesis meets the standard requirements for a dissertation in the field. In a closed discussion and after a secret ballot, the committee concluded that the doctoral candidate has fulfilled the conditions of Section 47, Paragraph 4 of the Higher Education Act No. 111/98 and can therefore be awarded the degree of Doctor (PhD).

Language of thesis

English

Faculty

Fakulta elektrotechniky a komunikačních technologií

Department

Department of Electrical Power Engineering

Study programme

Power Systems and Power Electronics (DKC-SEE)

Composition of Committee

prof. RNDr. Vladimír Aubrecht, CSc. (předseda)
doc. Ing. Ondřej Vítek, Ph.D. (člen)
doc. Ing. Jaroslava Orságová, Ph.D. (člen)
doc. Ing. Jiří Hošek, Ph.D. (člen)
Ing. Petr Modlitba, CSc. (člen)
prof. Ing. Peter Braciník, Ph.D. (člen)
prof. Ing. Radomír Goňo, Ph.D. (člen)
prof. Matti Lehtonen (člen)
prof. Ing. Jiří Drápela, Ph.D. (člen)

Supervisor’s report
prof. Ing. Petr Toman, Ph.D.

Matěj Vrtal started his PhD study in 2020. He passed doctoral state examination in 2022 and in April 2025 he submitted his doctoral dissertation.
The thesis deals with advanced methods and tools for simulating and analyzing interdependent critical infrastructures, with a primary emphasis on the energy and data communication sectors.
The thesis is written as a set of scientific papers, which are focused on the topic of the dissertation, and which were published in conference proceedings and in journals.
The papers cover three main research areas: (i) design and development of a simulation tool, (ii) modelling of system unavailability and maintenance optimization, and (iii) validation of the applied methods in real-world scenarios.
The developed simulation platform enables multilayer simulation of interconnected infrastructures with a modular and scalable architecture and support for future integration of additional subsystems.
The simulator provides a tool for risk assessment, outage prediction and reliability optimization and is to be primarily utilized by two key user groups: distribution system operators and municipalities.
The topic of this dissertation is up-to-date. The doctoral dissertation brings substantial scientific progress and new findings relevant to the given subject.
During his studies, Matěj Vrtal devoted a lot of effort to the elaboration of the theoretical and practical parts of the dissertation and demonstrated the ability to do independent scientific work.
As part of his studies, he has participated in the teaching of exercises in the subject of Design of Power and Data Network including international project Micro degree for modern harmonized electrical engineering, where he has coordinated part on Modern Electrical Design.
In 2021/2022 he spent 3 months at Aalto University in Finland and in 2022/23 3 months at University of Wuppertal in Germany.
He is a member of several research project teams and was a significant member of the teams which prepared project proposals.
Matej Vrtal is the author or co-author of 14 articles in the proceedings of international and national conferences and 3 articles in journals with impact factor. There are 17 records in the Scopus database and 5 records in the Web of Science database, h index is 1.
I am convinced that the candidate meets all the prerequisites for the award of the academic title Doctor.
I recommend the dissertation for defence.

Reviewer’s report
prof. Ing. Radomír Goňo, Ph.D.

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Posudek oponenta [.pdf] 172,23 kB

Reviewer’s report
prof. Matti Lehtonen

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File inserted by the reviewer Size
Posudek oponenta [.pdf] 875,66 kB

Responsibility: Mgr. et Mgr. Hana Odstrčilová