Search for dissertations about: "tillförlitlighet"

Showing result 1 - 5 of 144 swedish dissertations containing the word tillförlitlighet.

  2. 1. Reliability-based fatigue assessment of existing steel bridges

    Author : Ruoqi Wang; John Leander; Raid Karoumi; John Dalsgaard Sørensen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; steel bridges; reliability analysis; spatial correlation; risk analysis; Monte Carlo simulation; Utmattning; stålbroar; tillförlitlighet; rumslig korrelation; riskanalys; Monte Carlo-simulering; Structural Engineering and Bridges; Bro- och stålbyggnad;

    Abstract : Fatigue is among the most critical forms of deterioration damage that occurs tosteel bridges. It causes a decline of the safety level of bridges over time. Therefore,the performance of steel bridges, which may be seriously affected by fatigue, shouldbe assessed and predicted. READ MORE

  4. 2. Fatigue of existing steel bridges : Reliability and risk analyses for decision-making

    Author : Ruoqi Wang; John Leander; Raid Karoumi; Boulent Imam; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; steel bridges; decision-making; reliability analysis; risk analysis; spatial correlation; system modelling; inspection and maintenance; Utmattning; stålbroar; beslutsfattande; tillförlitlighet; riskanalys; rumslig korrelation; systemmodellering; inspektion och underhåll; Bro- och stålbyggnad; Structural Engineering and Bridges;

    Abstract : Fatigue is one of the primary reasons that limit the service life of steel bridges. Many bridges in Sweden and other countries have progressively approached their anticipated service lives. Since funding and resources are limited, simultaneously replacement or maintenance of bridges is impractical. READ MORE

  5. 3. Fault location in resonant earthed medium voltage distribution systems

    Author : Md Zakaria Habib; Nathaniel Taylor; Mohamed F. Abdelfattah; Matti Lehtonen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical distribution; Distribution network; Reliability; SAIDI; Fault location; FL; Fault passage indicator; FPI; Compensated neutral; Resonant earthing; Resonant grounding; Petersen coil; Arc suppression coil.; Distributionsnät; Tillförlitlighet; Fellokalisering; FL; Felpassageindikation; FPI; Kompenserat nät; Spoljordat nät; Petersenspole.; Electrical Engineering; Elektro- och systemteknik;

    Abstract : A major challenge in electric distribution systems is to increase the reliability of the electricity supply in an economical way. At the final medium-voltage level in the system, such as 10 kV or 20 kV, a single feeder may supply tens of medium/low-voltage transformers and hundreds of customers, with many branches of lines and cables where faults can occur. READ MORE

  6. 4. Refining the fatigue assessment procedure of existing steel bridges

    Author : John Leander; Raid Karoumi; Bert Norlin; John D. Sørensen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; Steel bridges; Assessment; Reliability; Monitoring; Utmattning; stålbroar; bärighetsberäkning; tillförlitlighet; mätningar; Söderström; getingmidjan;

    Abstract : This thesis treats the fatigue assessment process of steel bridges. The purpose is to identify areas with potential of enhancement with an overall aim of attaining a longer service life. The aging bridge stock in Sweden and in many other developed countries is an impending economical burden. READ MORE

  7. 5. On Reliability of SiC Power Devices in Power Electronics

    Author : Diane-Perle Sadik; Hans-Peter Nee; Per Ranstad; Nando Kaminski; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon Carbide; Metal-Oxide-Semiconductor Field-Effect Transistor MOSFET ; Junction Field-Effect Transistor JFET ; Bipolar Junction Transistor BJT ; Reliability; Failure Analysis; Reliability Testing; Short- Circuit Currents; Humidity; Resonant converter; Series-resonant converter SLR ; Base drive circuits; Gate drive circuits; Life-Cycle Cost Analysis LCCA ; Kiselkarbid; MOSFETar; JFETar; Bipolär Junction Transistor BJT ; Tillförlitlighet; Robusthet; Felanalys; Tillförlitlighetstestning; Kortslutningsströmmar; Luftfuktighet; Resonansomvandlare; Serie-resonansomvandlare SLR ; Basdrivkretsar; Gate-drivkretsar; Felskydd; Livscykelkostnadsanalys; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Silicon Carbide (SiC) is a wide-bandgap (WBG) semiconductor materialwhich has several advantages such as higher maximum electric field, lowerON-state resistance, higher switching speeds, and higher maximum allowablejunction operation temperature compared to Silicon (Si). In the 1.2 kV - 1. READ MORE