@phdthesis{01HGX4M0TCVKDF7X0TNHRST5XF,
  abstract     = {{Power systems around the world are witnessing changes that are unprecedented in the history of the electricity grid. The power system from the very beginning has heavily relied upon conventional energy sources such as coal and oil. The reason being the abundance and acceptable efficiency of these sources. The growing demand of electricity and constantly depleting dispatchable sources of energy kindled the need for alternatives. The negative environmental impact of the usage of these sources is evident. The dominance of fossil fuels in the energy industry led to unforeseen detriment to the climate. Such fuels are the main driver of global warming. Their usage release vast amount of harmful greenhouse gases (GHG) such as carbon dioxide CO2. These GHG are responsible for trapping a great amount of heat in the earth's atmosphere leading to disastrous outcomes, droughts, changed rainfall patterns and higher temperatures, to name a few.

Considering the fact that the continued usage of conventional energy sources can result in an irreparable damage to the environment, the world is moving towards an energy transition. Energy transition refers to the shift from conventional polluting energy sources to clean and more sustainable alternatives. The aim is to combat the climate change by reducing GHG and confine or possibly reduce the environmental damage. An irreplaceable tool for this transition is more reliance on renewable energy. Renewable energy sources have the potential to transform the energy system by making it more sustainable. Some of the prime renewable energy sources are wind, solar, hydro, tidal, geothermal and biomass. The energy generated from such sources are tapped from natural processes that have lesser or no impact on the environment. Generating energy from renewable sources does not emit GHG and pollute the atmosphere like fossil fuels. The numerous benefits of renewable energy include improved health due to less air pollution, clean and sustainable energy system, energy security, etc. These advantages have led to a prominence of renewable energy in the past decades. With each passing year the share of renewable energy in the energy mix is increasing, leading a pathway to a more sustainable power system.

Amongst the renewable energy sources, wind energy has the promise of providing an efficient mode of clean energy. Wind energy works on the principle of converting kinetic energy available in the wind to usable electrical energy. At the power production stage, modern wind turbines do not produce any GHG, making them an ideal and reliable alternative for the energy transition. Its abundant and inexhaustible nature makes it a suitable form of energy generation across the world. As a result, with time and improved technologies, wind energy has become more accessible and is now used in international grids as well as small ill-connected island networks. Despite all its benefits, the seamless inclusion of wind energy into the power system does not come without challenges.

Wind is constantly varying, making wind energy intermittent in nature. The production of energy from wind is not constant and fluctuations are seen depending on the geographical location, air pressure, etc. The intermittent nature of wind energy poses challenges for the Transmission System Operator (TSO), as the exact energy production is unpredictable. The advances in technology such as energy storage systems have come to aid, providing reliability to wind energy systems (WES). The accurate forecasting of wind is crucial for the reliability of wind energy. Wind forecasting methods are continuously evolving. Big data analysis and artificial intelligence (AI) based models are now able to predict the short term wind forecast with a high accuracy.

These developments in the area of wind energy have equipped wind power producers (WPPs) to actively participate in ancillary services such as primary reserve. Active primary reserve services such as frequency containment reserve (FCR) and fast frequency reserve (FFR) can greatly benefit from the participation of wind farms. In fact, in the power systems with high penetration of wind energy, such provision of primary reserve is a necessity. However, there has been limited research in the area of the effect of primary reserve provision by wind turbines on the health, surroundings and WPP's revenue. This dissertation addresses these issues.

The primary reserve service, FCR requires a fast adjustment in the power output based on the changes in the grid frequency. This is a challenging task as the required response time is within seconds. Therefore, for the research work presented in this dissertation the first task is to develop a fast acting control system. To validate the effectiveness of the control, it is then validated using the pre-qualification established by the Belgian TSO Elia.

Wake effects are a well known phenomenon in wind farms. A wind turbine located in the wake trail of an operational wind turbine experiences a lower, disturbed wind speed causing a decrease in the former's energy production. Due to this, wind farms are designed such that the interference is minimal. However, many countries such as Belgium have wind farms that have a high capacity density, prevailing the effect of wake. Moreover, the effect of providing FCR on the wake trail behind a wind turbine is not studied. For this purpose, this research aims to study such wake behaviours. The dynamic behaviour of wake is studied for a range of scenarios with varying grid frequency and wind profiles.

Due to the control action related to the provision of FCR, a variation in the loads on different parts of the wind turbine is expected. The major loads on wind turbine components such as main bearing, blades, shaft and tower are studied. These loads are then combined using a methodology to quantify the overall load on a wind turbine. The loading results are used in an optimisation algorithm to generate optimal reserve and energy market bids such that a balance between wind turbine loading and the WPP's revenue is created.

Another aspect presented in this dissertation is related to optimal control strategies of wind turbines. For this objective optimal strategies for WPPs are developed that ensure the power output regulation to meet the energy and reserve market contracted bids while considering the real-time wind variations.}},
  author       = {{Singh, Narender}},
  isbn         = {{9789463557788}},
  keywords     = {{Ancillary services,Primary reserve,Fast frequency reserve,Frequency containment reserve,Wake effect,Wind energy,Wind turbine component lifetime analysis,wind turbine loading}},
  language     = {{eng}},
  pages        = {{XXVI, 145}},
  publisher    = {{Ghent University. Faculty of Engineering and Architecture}},
  school       = {{Ghent University}},
  title        = {{The dynamic impact of ancillary service provision on wind turbine operation, loading and wake}},
  year         = {{2023}},
}