Coordinated reactive power control of DFIG rotor and grid sides converters

Doubly fed induction generators used in grid interfaced wind energy systems are increasingly being called upon to address voltage regulation and provide adequate reactive power support. This paper presents a new coordinated control strategy using both the grid and rotor side converters for voltage regulation and reactive power support considering operational limits and network side voltage fluctuations. The central idea here is to derive the reactive power reference signal (in the RSC control loop) from the terminal voltage controller in the GSC control loop. Coordinating the control loops in this manner enables the DFIG to regulate the terminal voltage in a superior manner (compared to uncoordinated control). Wind speed is modeled by NREL TurbSim and the turbine model includes wind shear and tower shadow. The maximum power point tracking (MPPT) is taken into account in DFIG active power control. Simulation results demonstrate the effectiveness of proposed control strategy during the variations of network voltage, wind speed, output active and reactive power.