Search for dissertations about: "circuit breaker"

Showing result 1 - 5 of 7 swedish dissertations containing the words circuit breaker.

  1. 1. On the design of hybrid DC-breakers consisting of a mechanical switch and semiconductor devices

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Jesper Magnusson; KTH.; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DC; circuit breaker; hybrid breaker; DC systems; DC; brytare; hybridbrytare; likström;

    Abstract : The interest of using direct current in networks for both transmission and distribution of power is increasing due to the higher efficiency compared to the alternating current used today. As no natural zero crossings exist in direct current, the interruption of fault currents becomes a challenge. READ MORE

  2. 2. Condition measuring and lifetime modelling of disconnectors, circuit breakers and other electrical power transmission equipment

    University dissertation from Stockholm : Kungliga Tekniska högskolan

    Author : Per Westerlund; KTH.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reliability; maintenance; condition monitoring; disconnector; circuit breaker; Weibull distribution; prediction; risk analysis; decision making; beta distribution; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The supply of electricity is important in modern society, so the outages of the electric grid should be few and short, especially for the transmission grid. A summary of the history of the Swedish electrical system is presented. The objective is to be able to plan the maintenance better by following the condition of the equipment. READ MORE

  3. 3. On reliability and maintenance modelling of ageing equipment in electric power systems

    University dissertation from Stockholm : KTH

    Author : Tommie Lindquist; KTH.; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reliability; maintenance; electric power systems; circuit breaker; disconnector; thermography; TECHNOLOGY Electrical engineering; electronics and photonics Electric power engineering; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Elkraftteknik;

    Abstract : Maintenance optimisation is essential to achieve cost-efficiency, availability and reliability of supply in electric power systems. The process of maintenance optimisation requires information about the costs of preventive and corrective maintenance, as well as the costs of failures borne by both electricity suppliers and customers. READ MORE

  4. 4. Three Phase Controlled Fault Interruption Using High Voltage SF6 Circuit Breakers

    University dissertation from Stockholm : KTH

    Author : Richard Thomas; [2007]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; controlled switching; high voltage; hypothesis testing; circuit breakers; fault interruption; least mean squares regression; power system protection;

    Abstract : A method is presented for implementing controlled fault interruption,using high voltage, SF6 circuit breakers on three phase high voltage powernetworks. The main goal of the method is to synchronize the opening or tripcommands to each phase of a circuit breaker with respect to target currentzero times so that each phase will interrupt with a preselected arcingtime. READ MORE

  5. 5. Studies on Current Commutation in Hybrid DC-breakers

    University dissertation from KTH Royal Institute of Technology

    Author : Jesper Magnusson; KTH.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commutation; Hybrid DC-breakers; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Compared to conventional AC-circuit breakers, a DC-breaker has to act fast and force the current down to zero. Many different DC-breaker topologies are available, and this thesis is focused on the hybrid DC-breaker comprising a mechanical switch and high power semiconductors. READ MORE