Search for dissertations about: "circuit breakers"

Showing result 1 - 5 of 16 swedish dissertations containing the words circuit breakers.

  2. 1. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

    Author : Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

    Abstract : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. READ MORE

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

    Author : Richard Thomas; Chalmers tekniska högskola; []
    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. 3. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

    Author : Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
    Keywords : Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. READ MORE

  6. 4. 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 : 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

  7. 5. Condition measuring and lifetime modelling of electrical power transmission equipment

    Author : Per Westerlund; Patrik Hilber; Tommie Lindquist; Carl-Ejnar Sölver; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; disconnectors; circuit breakers; reliability; lifetime; electric contacts; electric power transmission; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The electric grid is important in modern society, so the outages should be few. The transmission grid should have a real high availability, since it transports electrical energy across the country. Then, it is difficult to plan outages for maintenance and installation. READ MORE