The Integrated Control of the Rotor Side and Grid Side Converters in a DFIG to Reduce Both Stator Power and Torque Pulsations During Network Voltage Unbalance Conditions.

In Ireland, usually the most productive sites for wind turbines and wind farms are in rural remote areas where the distribution network can be weak and voltage unbalance can be a common feature. Induction generators subjected to network voltage unbalance can overheat due to the excessive currents, and mechanical stress can occur due to torque pulsations. The rotor converter in a double-fed induction generator (DFIG) is also susceptible to high currents during periods of voltage unbalance. A DFIG wind turbine is modelled in Matlab/Simulink to analyse the behaviour of the induction generator and rotor converter to grid network voltage unbalance. The control schemes of the rotor-side converter and grid-side converter are modified in a coordinated method to reduce the DFIG stator power and torque pulsations as a result of supply network voltage unbalance conditions.