Low Voltage Ride Through for a Wind Turbine Based SCAG

This paper develops a control strategy for a large wind turbine based on the squirrel cage asynchronous generator (SCAG). In addition, the transient behavior during Low Voltage Ride Through (LVRT) of the system is studied. To this end, the wind turbine connected to the grid is controlled in such way to inject maximum power into the grid and provide a reactive power to regulate the grid voltage, in order to satisfy the grid code requirement (GCR). Hence, the side-generator converter is used to control the generated power from a wind turbine and oriented the rotor flux whereas the grid side converter is used to maintain the DC link voltage constant and control the active power and reactive power required to maintain the grid voltage. The system under study is developed to select one of two operating modes: the first one is the maximum power point tracking ( MPPT) and the second is the fault mode which, is activated when a fault occur in the grid. The results of simulation are given through MATLAB/Simulink and show that the wind energy conversion system (WECS) is efficient, ensures good performances and satisfies the grid code requirement.