Search for dissertations about: "circuit breaker"

Showing result 1 - 5 of 8 swedish dissertations containing the words circuit breaker.

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

   Author : Jesper Magnusson; Göran Engdahl; Staffan Norrga; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

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

   Author : Per Westerlund; Patrik Hilber; Tommie Lindquist; William Q Meeker; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

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

   Author : Tommie Lindquist; Roland Eriksson; Lina Bertling; George Anders; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reliability; maintenance; electric power systems; circuit breaker; disconnector; thermography; Electric power engineering; 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

6. 4. Studies on Current Commutation in Hybrid DC-breakers

   Author : Jesper Magnusson; Göran Engdahl; Magne Runde; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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

7. 5. On reliability modelling of ageing equipment in electric power systems with regard to the effect of maintenance

   Author : Tommie Lindquist; Prof. Roland Eriksson; Dr. Lina Bertling; Docent Carl-Ejnar Sölver; KTH; []
   Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; Maintenance; reliability modelling; electrical power systems; ageing; failure mechanisms; Elkraftteknik; Electric power engineering; Elkraftteknik;

   Abstract : Power system maintenance optimisation involves obtaining the minimum total costs, including preventive and corrective maintenance costs and the cost of failures for both supplier and customer. To calculate the cost of failure, information is needed about the equipment reliability characteristics. READ MORE