Wind generator control in compliance with new norms

Abstract

The level of wind penetration in the total generated electrical energy in Germany is increasing in such a way that new norms for connecting wind power stations to the electric power system are prescribed by the power companies. Windmills are no longer to be seen as "negative" consumers but rather as conventional power stations. This means that wind power stations in the near future must fulfill requirements like supporting the mains supply during faults, controlling reactive power and limiting transient currents at start-up. Brazil is setting a very good example by complying with the Kyoto protocol and its government program for supporting the construction of wind farms. With its potential and the commitment of the new administration in further developing the implantation of renewable energy sources these advances happening in countries like Germany, where the wind energy has achieved such development level, have to be taken into account to guarantee power quality in the future. This work presents a control scheme for a doubly fed induction generator in windmills focusing on power flow optimisation. By controlling reactive power system losses are minimised and other goals are also achieved in meeting the requirements of the new generation of wind power stations.