A study on the dynamic behavior of a DFIG with sensorless-based control in cooperation with a fuzzy controlled energy storage system

The present study deals with the combined operation of a doubly-fed induction generator (DFIG) with sensorless based control, which is common to wind energy conversion systems (WECSs) and an energy storage system (ESS). The scope of this paper is to present a coordinative control system to enhance the DFIG ability to recover from a fault condition. Despite the numerous benefits of the sensorless control, this approach suffers from high sensitivity to the dynamics effects. Herein, a three-phase short-circuit is considered as a significant and most common dynamic effect. The newly protection method - combined with the classical protection methods, i.e. crowbar, breakers - refers to a battery based energy storage system connected to the DC link of the back to back converter through a fuzzy-controlled bidirectional DC/DC converter. The aforementioned configuration aims to mitigate the DC bus voltage fluctuations during grid faults and subsequently to ensure the seamless operation of the overall system. The set-up was modeled via Matlab/Simulink and the simulation results obtained, validated the effectiveness of the proposed control system.