Sökning: "Lennart Harnefors"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Lennart Harnefors.
1. On analysis, control and estimation of variable-speed drives
Sammanfattning : .... LÄS MER
2. On the Internal Dynamics and AC-Motor Drive Application of Modular Multilevel Converters
Sammanfattning : This thesis is an effort to investigate the operation and the performanceof modular multilevel converters (M2Cs). Proven to be the most promisingtopology in high-voltage high-power applications, it is necessary to put aneffort in understanding the physical laws that govern the internal dynamicsof such converters, in order to design appropriate control methods. LÄS MER
3. Hybrid Converters for HVDC Transmission
Sammanfattning : The line-commutated converter (LCC) and the voltage-source converter (VSC) are the two main converter technologies utilized in high-voltage direct current (HVDC) transmission applications. Depending on the application requirements, one technology might be more advantageous than the other. LÄS MER
4. 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
5. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability
Sammanfattning : 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). LÄS MER