Using predictive model controller and SSR damping controller in order to improve performance of DFIG wind turbines

Nowadays, the doubly fed induction generators are widely used as variable speed wind turbine topology. The operation of series capacitive compensation increases the risk of sub-synchronous resonance. The SSR is occurred when the DFIG wind farm delivers energy to the grid at one or more natural frequencies. In order to prevent occurrence of such frequencies, control strategies should be implemented. In this paper a method of SSR damping control and optimal placement of Rotor side converter and grid side converter of series compensated DFIG wind farm is proposed. SSR damping controller is based on the residue method. Moreover the converters are improved by using model predictive controller (MPC). MPC is used to improve the stator current quality. By using MPC there is no need to PWM modulators and PI regulators and switching tables; hence the dynamic response could be suitably improved. Simulation results proved that the grid side converter is the optimal place for SSR damping controller implementation. Moreover the best control signal is the capacitor voltage.