Operation and Control of Large Wind Turbines and Wind Farms

The objective of this project is to analyse and assess the possibilities for control of different types of wind turbines and different wind farm concepts. The potentials of optimising the lifetime/energy production ratio by means of using revised operational strategies for the individual wind turbines are investigated. It is one of the the main objectives to clarify this potential by implementation of a strategy where the power production is decreased to an optimum when taking loads and actual price of produced electricity into account.Models and control strategies for the wind farms are developed, with the aim to optimise the operation of the wind farms considering participation in power system control of power (frequency) and reactive power (voltage), maximise power production, improve the influence on the power quality and limit mechanical loads and life time consumption. The wind farm control will be based on signals from wind turbine controllers. These signals will be used to predict the wind speed at the individual wind turbines on short term (i.e. from seconds to minutes) in order to enable the individual wind turbine controllers to respond in an optimal way to the wind speed fluctuations. The project will be based on 3 different concepts for wind farms, because the possible control will depend on which wind turbines and what wind farm concept is selected. The concepts include electric components such as induction generators with squirrel cages, doubly fed induction generators and modern HVDC techniques based on converters with full control capabilities, i.e. based on force commutated semiconductors. The included wind turbines will be pitch controlled as well as (active) stall controlled.