Project

HVDC offshore wind farms with MVDC power collection have recently aroused researchers' interest as these systems offer lower losses and fabrication expenses. Numerous potential MVDC converters could be used in the power collection stage of offshore wind farms; however, when it comes to the technology level, these DC/DC converters are still immature since no substantial studies concerning their control exist. Thus, this Ph.D. project aims to address the research gap to enhance the performance as well as the efficiency of an MVDC converter. The novel switching and control technique proposed in this project together with the significant features of wide bandgap switches provide the condition based on which the MVDC converter could operate at higher switching frequencies than what is already possible. Hence, the controlled MVDC converter will be smaller in size and lighter in weight compared to the conventional ones which reduces the LCOE and provides better possibilities for modularity.

This Bubble Project aims to assess the feasibility of revamping offshore oil and gas infrastructures transforming them into units producing methane from wind power.

Turkey is one of the fastest-growing energy markets in the world, with an annual 8% increase in energy demand. By the end of 2018, the total installed capacity and electricity production of Turkey was 88.5 GW and 300.7 TWh, respectively. Nowadays, more than 70% of all electricity production is supplied by fossil resources, and almost 30% of all electricity production comes from renewables, mainly hydro, while wind constitutes only 6.6% of the total electricity mix.

The wind and solar energy rate in total consumption are planned to be increased by at least 30% in the coming five years according to the 2023 vision plan of Turkey. However, due to the intermittent nature of wind energy, large-scale wind power integration may pose some serious challenges to Turkey's power system. Therefore, planning analysis and designing efforts are required to ensure the smooth, secure and reliable operation of Turkey's power system and electricity markets considering large-scale wind power integration. WindFlag aims to solve relevant challenges of large scale OWPP deployment and integration into the Turkish grid, such as extreme weak-grid situations, islanding conditions, and large harmonics and resonances.

The goal of the project is to significantly strengthen the scientific basis for the wind power industry in general and specifically the Danish wind power industry’s position in offshore applications.

To meet the goal the proposed research must have a significant potential for reduction of cost of energy from large offshore wind farms, and for contributing to reduction of the economic risks arising from inadequately founded design.

The key design driver for most offshore structures is safety. For offshore wind turbines/farms, however, the main design driver is economy and therefore there is a strong requirement for enhancing design tools and avoiding conservatism. Consequently, focus is on the following issues:

1. Mutual shadow effect between large blocks of wind turbines – ignorance of the effect may have disastrous consequences for the economy.
2. Extreme structural loading of offshore wind turbines – detailed understanding and description of extreme winds and gusts and resulting loads is crucial for the safety and economics of the wind turbines.
3. Interaction of large wind farms with waves and current – understanding and modeling may lead to reduced design loads on wind turbine units placed in the downwind end of the wind farms.
4. Grid connection and reliability – An unreliable grid caused by high wind energy penetration is an obvious barrier for the dissemination of the technology.
5. Optimized operation and maintenance for offshore wind farms – presently more than a third of the cost of energy from offshore wind farms relates to O&M and the potential for reductions is therefore large.

The project is sponsored by The strategic Research council and have participant from Risø National Laboratory, Elsam Engineering, Insitut for Mekanik, Energi og Konstruktion DTU, DHI, Svend Ole Hansen and Institute of Energy Technology AAU.

The institute of Energy Technology is especially involved in issue 4 in this project, by Birgitte Bak-Jensen, and also a Ph.D project is set up together with Risø and Elsam Engineering, with the title: Offshore Wind Power – Grid Connection and Reliability, see this project.