A reactive power-based adaptive approach for synchronization of DFIG into the weak grid to support existing WE infrastructure

Abstract

The synchronization of the Doubly-Fed Induction Generator (DFIG) into the weak AC grid is significantly affected due to the reactive power limitations associated with the built-in converter of the existing Wind Energy (WE) system. This is further restricted due to non-linear loads and Power Quality (PQ) deterioration. Therefore, there is a strong need for a system capable of managing reactive power without disturbing the existing infrastructure of WE sources. This paper proposes a novel reactive power-based solution for synchronizing the DFIG to the weak grid with high WE penetration by mitigating PQ disturbances and managing reactive power at the interconnection point using an additional Distribution-Static Compensator (DSTATCOM). A feed-forward second-order-based adaptive algorithm controls this reactive power compensator. The adaptive control extracts the active and reactive weights of load current to generate the reference signals by continuously tracking grid voltage, wind generation, and DC-link voltage. The proposed novel approach has been successfully implemented in MATLAB and validated with a laboratory-based experimental setup. The transient and steady-state analysis reveals the practical applicability of a proposed novel synchronization approach with a high WE penetration level.