Control algorithms and implementation for variable speed stall regulated wind turbines

In this research control algorithms and implementation for variable speed stall regulated wind turbines are presented. This type of wind turbine has a simpler and more robust construction and can have lower requirements for maintenance than the existing pitch regulated wind turbines. Due to these features these wind turbines can have reduced cost, which is a crucial parameter especially for large scale wind turbines. However, this type is not commercially available yet due to existing challenges in its control. In this research a complete control scheme for variable speed stall regulated wind turbines has been developed and implemented in a fully dynamic hardware-in-loop simulator for variable speed wind turbines. The simulator was developed as part of the project in order to validate the designed control algorithms. The developed control system uses novel adaptive methods in order to maximize the energy production of the wind turbines at below rated wind speeds as well as to control the power of the wind turbine at above rated wind speeds. In addition, several types of controllers including robust controllers have been used and tested, which resulted to novel control solutions for stall regulated wind turbines. The main advantage of the proposed control method is that it uses existing hardware without requiring additional sensors, so it more effectively exploits information coming from measurements available in existing wind turbine converters. Through software and hardware simulations the proposed control algorithms seem to be quite promising and give confidence for the future development of variable speed stall regulated wind turbines.