Sökning: "multilevel modeling"
Visar resultat 1 - 5 av 32 avhandlingar innehållade orden multilevel modeling.
1. Efficient Modeling of Modular Multilevel Converters for HVDC Transmission Systems
Sammanfattning : The drive towards getting more and more electrical energy from renewable sources, requires more efficient electric transmission systems. A stronger grid, with more controllability and higher capacity, that can handle power fluctuations due to a mismatch between generation and load is also needed. LÄS MER
2. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges
Sammanfattning : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. LÄS MER
3. Modeling of Modular Multilevel Converters for Stability Analysis
Sammanfattning : Modular multilevel converters (MMCs) have recently become the state-of-the-art solution for various grid-connected applications, such as high-voltage direct current (HVDC) systems and flexible alternating current transmission systems (FACTS). Modularity, scalability, low power losses, and low harmonic distortion are the outstanding properties that make MMCs a key technology for a sustainable future. LÄS MER
4. Modeling and Design of Modular Multilevel Converters for Grid Applications
Sammanfattning : This thesis aims to bring clarity to the dimensioning aspects and limiting factors of the modular multilevel converter (MMC). Special consideration is given to the dc capacitors in the submodules as they are a driving factor for the size and weight of the converter. LÄS MER
5. Effective schools in a segregated landscape : Studies of academic achievement and psychological well-being among adolescents in Sweden
Sammanfattning : Equitable educational opportunities necessitate equitable access to a favourable academic and social school environment. This thesis aims to explore the role of the school as an educational and social arena for the academic achievement and psychological well-being of lower secondary school students in Sweden. LÄS MER