Search for dissertations about: "Variable Speed Limits"

Showing result 11 - 15 of 16 swedish dissertations containing the words Variable Speed Limits.

  2. 11. Diving Deep into Saturn's Equatorial Ionosphere with Cassini : Insights from the Grand Finale

    Author : Joshua Dreyer; Erik Vigren; Michiko Morooka; Jan-Erik Wahlund; Ingo Müller-Wodarg; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Saturn; Cassini; Grand Finale; Ionosphere; Photochemistry; Planetary Rings; Planetary Science; Space Plasma; Space Physics; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Abstract : In the summer of 2017, the Cassini mission concluded its nearly 13 years orbiting Saturn with a series of daring dives between the rings and the upper reaches of Saturn's atmosphere. This last phase of the mission, called the Grand Finale, revealed a highly variable equatorial ionosphere dominated by a large influx of ring material from Saturn's D ring. READ MORE

  4. 12. Dynamic Rating of Power Lines and Transformers for Wind Energy Integration

    Author : Kateryna Morozovska; Patrik Hilber; Rajeev Thottappillil; Rebei Bel Fdhila; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic line rating; dynamic transformer rating; power transformers; heat balance; thermal modeling; wind power; wind energy integration; reliability analysis; risk analysis; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Dynamic Rating (DR) is usually associated with unlocking the capacity of power lines and transformers using available information on weather conditions. Our studies show that Dynamic Rating is a broad concept that requires further study and development. READ MORE

  5. 13. Partial Discharges at Fast Rising Voltages

    Author : Thomas Hammarström; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; short rise time; cavities; high dV dt.; measurements; Partial discharges; square like voltages; repetitive voltages;

    Abstract : The present demand for higher efficiency and flexibility in the energy sector has led to an increased use of power electronic generated waveforms as these allow energy conversion between different frequencies including DC. The generated waveforms are usually synthesized by so called Pulse Width Modulation (PWM) techniques, where the desired waveform is approximated by a number of square shaped pulses with a short rise time. READ MORE

  6. 14. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

    Author : Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power system control; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; fundamental control limitations; frequency stability; hydro power; wind power; non-minimum phase; zero dynamics; eigenvalue analysis; Electrical Engineering; Elektro- och systemteknik;

    Abstract : With the transition towards renewable energy and the deregulation of the electricity markets, the power system is changing. Growing electricity demand and more intermittent power production increase the need for transfer capacity. Lower inertia levels due to a higher share of renewables increase the need for fast frequency reserves (FFR). READ MORE

  7. 15. The Internalization of External Effects in Swedish Transport Policy - A Comparison Between Road and Rail Traffic

    Author : Lars Hansson; Internationella miljöinstitutet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Commercial and industrial economics; rail traffic; road traffic; transport policy; internalization; External effects; pricing-relevant costs; Industriell ekonomi;

    Abstract : Transport is a key factor for economic growth. It has enabled both the economic scale of production and an increase in competition. No one can question this role of transportation. There is, however, a back-side to the coin: the environmental challenge. READ MORE