Optimized control of Coordinated Series Resistive Limiter and SMES for improving LVRT using TVC in DFIG-base wind farm

摘要

Maintaining connectivity to the grid and resisting against voltage dip in the grid are important for doubly fed induction generator based wind farms (DFIG-based WFs) to meet the requirements of new grid codes. In this paper, a hybrid approach is proposed to improve low voltage ride through (LVRT) capability in DFIG-based WF using an improved series resistive limiter (SRL) in rotor and superconducting magnetic energy storage (SMES) as an improved chopper circuit (ICC) along with the transient voltage control (TVC) method. The connection of the wind turbine to the grid while preventing the disturbances duo to the voltage dip (VD) through compensating the VD by using the proposed controller and ICC method. The new control method relies on active power control and reactive power injection to the grid for improving the performance of DFIG-based WF during the grid VD. The proposed controller and ICC method reduce the VD at the point of common coupling (PCC) while improving the overall system performance by injecting active and reactive power into the grid during a fault. In addition, the proposed methods effectively improves the LVRT capability of the generator and maintains its controllability during a fault Compared to other solutions including the crowbar parallel resistance. The proposed methods are simpler, cheaper, and have less computational complexity compared to active methods including series voltage compensator of the stator along with power electronic converters (PEC). Finally, the continuous operation of a 9 MW wind turbine during a VD in the grid has been investigated and simulated using the proposed method in Matlab/Simulink (R).