Search for dissertations about: "snubber"
Showing result 1 - 5 of 7 swedish dissertations containing the word snubber.
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1. Cost-effective Cells for High-power Modular Multilevel Converters
Abstract : The modular multilevel converter (MMC) topology was introduced in 2003and has since been receiving considerable attention from industry and academia.Notable benefits compared to two- or three-level voltage source convertersare its scalability, low switching losses, low output filter requirementsand ease of adding redundancy combined with fail-safe operation. READ MORE
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2. Energy Evaluation for DC/DC Converters in DC-Based Wind Farms
Abstract : In this thesis the suitability of three topologies for DC/DC converters in a DC wind farm grid is investigated from an energy efficiency and energy production cost point of view. The three selected topologies are the fullbridge converter, the single active bridge converter and the series parallel resonant converter. READ MORE
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3. On the design of hybrid DC-breakers consisting of a mechanical switch and semiconductor devices
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
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4. High Frequency Model of Electrified Railway Propulsion System for EMC Analysis
Abstract : A model of the electrified railway propulsion system working in a wide frequency range is studied in this thesis. The high frequency modeling is the first stage to study and predict the Electromagnetic compatibility (EMC) problems in the electrified railway propulsion system, which are safety and reliability issues of high concern. READ MORE
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5. Studies on Current Commutation in Hybrid DC-breakers
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