An enhanced Whale Optimization Algorithm based Control Strategy for LVRT Capability Enhancement of Grid-Connected DFIG-WECS

A novel application of enhanced whale optimization algorithm (EWOA) is proposed in this research work to improve the low voltage ride through (LVRT) capability of the grid-connected doubly fed induction generator (DFIG) based wind energy conversion system (WECS). The EWOA is proposed in this article due to rapid convergence velocity, simple construction, and low computational burden. The proposed EWOA modifies the gains of all proportional-integral (PI) controllers at a high convergence speed. The optimal PI controllers are designed by the proposed EWOA. There are four PI controllers are employed in the rotor side converter (RSC), and another four PI controllers are applied in the grid side converter (GSC) under the cascaded structure. The DFIG is integrated into the grid through RSC and GSC with a common dc-link capacitor. The RSC is regulated to reduce the active power loss by using cascaded structure-based PI controllers, whereas GSC is regulated to keep constant the dc-link voltage and grid side reactive power. The validity of the proposed EWOA-PI controllers is verified by comparing the results with whale optimization algorithm (WOA) based PI controllers under severe grid disturbances. The LVRT capability is performed using the MATLAB program.