Showing 1 - 10 of 27,048
This paper aims to explore a viable solution for a doubly-fed induction generator (DFIG)-based wind farm to meet the reactive support requirement of the low voltage ride-through (LVRT) grid code with safe grid-connected operation during asymmetrical grid faults. First, the control scheme for the...
Persistent link: https://www.econbiz.de/10010692414
In the last 15 years, the use of doubly fed induction machines in modern variable-speed wind turbines has increased rapidly. This development has been driven by the cost reduction as well as the low-loss generation of Insulated Gate Bipolar Transistors (IGBT). According to new grid code...
Persistent link: https://www.econbiz.de/10011030829
A power router has been recently developed for both AC and DC applications that has the potential for smart-grid applications. This study focuses on three-phase power switching through the development of an experimental setup which consists of a three-phase direct AC/AC matrix converter with a...
Persistent link: https://www.econbiz.de/10011261877
For achieving the European renewable electricity targets, a significant contribution is foreseen to come from offshore wind energy. Considering the large scale of the future planned offshore wind farms and the increasing distances to shore, grid integration through a transnational DC network is...
Persistent link: https://www.econbiz.de/10011031366
In the field of photovoltaic (PV) plants and energy conversion from renewable sources, a large part of the technical literature is more devoted to practical aspects (new solar cells, electrically driven PV panels, safety, reduction of parasitic currents, etc.) than to theoretical investigations....
Persistent link: https://www.econbiz.de/10010668141
The second law of thermodynamics and, specifically, exergy analysis have been traditionally used for the assessment and optimization of energy systems. Nevertheless, as shown in this paper, exergy could also constitute a powerful tool for the evaluation of mineral commodities. That said, new or...
Persistent link: https://www.econbiz.de/10011133882
The paper proposes a back-to-back 2L-3L grid connection topology for a marine current energy converter. A prototype marine current energy converter has been deployed by a research group at Uppsala University. The concept behind the prototype revolves around a fixed pitch vertical axis turbine...
Persistent link: https://www.econbiz.de/10011133883
More and more wave energy converter (WEC) concepts are reaching prototypelevel. Once the prototype level is reached, the next step in order to further decrease thelevelized cost of energy (LCOE) is optimizing the overall system with a focus on structuraland maintenance (inspection) costs, as...
Persistent link: https://www.econbiz.de/10011096205
Though the importance of curvature continuity on compressor blade performances has been realized, there are two major questions that need to be solved,<i> i.e.</i>, the respective effects of curvature continuity at the leading-edge blend point and the main surface, and the contradiction between the...
Persistent link: https://www.econbiz.de/10011096206
This paper presents the results of an extensive study of two thermal energy storage (TES) systems. The goal of the research is to make solar energy cost-competitive with other forms of electricity. A small-scale TES system was first built. The inner to outer layers were made of firebrick (FB),...
Persistent link: https://www.econbiz.de/10011096207