Search for dissertations about: "protection of power systems"

Showing result 1 - 5 of 83 swedish dissertations containing the words protection of power systems.

  2. 1. Steady State Operation and Control of Power Distribution Systems in the Presence of Distributed Generation

    Author : Ferry Viawan; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distance protection; stochastic assessment; voltage dip; line drop compensation; distribution systems; on-load tap changer; overcurrent protection; sensitive equipment; voltage dip immunity; voltage control; short circuit; reactive power control; pilot protection.; protection coordination; protection; Distributed Generation; losses;

    Abstract : In this thesis, the impact of distributed generation (DG) on steady state operation and control of power distribution systems is investigated. Over the last few years, a number of factors have led to an increased interest in DG schemes. DG is gaining more and more attention worldwide as an alternative to large-scale central generating stations. READ MORE

  4. 2. Towards Systemic Governance of Critical Infrastructure Protection : State and Relevance of a Swedish Case

    Author : Christine Große; Aron Larsson; Olof Björkqvist; Pär M. Olausson; Alexander Fekete; Mittuniversitetet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Systemic Thinking; Infrastructure; Governance; Critical Infrastructure Protection; Complex Systems; Soft Operations Research; design-oriented Information Systems Research; Integrative System Analysis; KISA; STYREL; Multi-level Planning; Adaption; Emergence; Entropy; Systemic Governance;

    Abstract : The protection of infrastructure that is critical to society’s functionality, survival and progression has gained significance for both national security and research because of its large-scale and interdependent nature. Critical infrastructure can be viewed as a complex, socio-technical system-of-systems that imposes extensive requirements on governance efforts to foster critical infrastructure protection (CIP), regardless of whether it involves public organisations, private organisations or both. READ MORE

  5. 3. Modeling, Control and Protection of Low-Voltage DC Microgrids

    Author : Daniel Salomonsson; Lennart Söder; Brian K. Johnsson; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; circuit transient analysis; dc power systems; dispersed storage and generation; load modeling; power conversion; power distribution control; power distribution faults; power distribution protection; power electronics; Electric power engineering; Elkraftteknik;

    Abstract : Current trends in electric power consumption indicate an increasing use of dc in end-user equipment, such as computers and other electronic appliances used in households and offices. With a dc power system, ac/dc conversion within these loads can be avoided, and losses reduced. READ MORE

  6. 4. Protection Strategies to Mitigate Major Power Systems Breakdowns

    Author : Mattias Jonsson; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; system protection schemes; transient instability; distance protection; power swing detectors; voltage instability; generator coherency; wide area protection; out-of-step protection;

    Abstract : This thesis deals with new methods to improve the performance of power system protection in the case of voltage- and transient instability. These methods are designed primarily to mitigate power system breakdown. Relay algorithms are proposed where conventional distance protection is combined with additional relay criteria. READ MORE

  7. 5. Differential Protection for Arbitrary Three-Phase Power Transformers

    Author : Zoran Gajic; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric power systems; power transformers; differential protection; power system protection;

    Abstract : This thesis describes how to provide standardized, current based, differential protection for any three-phase power transformer, including phase-shifting transformers with variable phase angle shift and transformers of all construction types and internal on-load tap-changer configurations. The use of standard transformer differential protection for such applications is considered impossible in the protective relaying standards and practices currently applied. READ MORE