Control coordination between DFIG-based wind turbines and synchronous generators for optimal primary frequency response

Abstract

This paper proposes a novel coordinating mechanism between synchronous generators (SGs) and wind turbines (WTs) based on doubly-fed induction generators (DFIGs) for enhanced primary frequency regulation. WTs are urged to participate on frequency regulation, specially if wind power penetration keeps increasing. WTs control support is possible, but it is transient due to the WTs lack of energy storage. This drawback can result in either a further delayed response from the governors of SGs or further frequency decay when WTs support is over. The proposed coordination attempt to tackle this issue. An artificial neural network (ANN) is used to obtain an optimal coordination signal to improve frequency response. As a proof of concept, the proposed coordination is tested on a 9-bus test system that includes a wind farm with 5 WTs. Simulation results show that frequency nadir is reduced in about 22% and rates of change of the system frequency (RoCoF) in about 29.5%. Further work is needed to validate this concept in large-scale systems, but the development and results obtained so far are promising to strengthen power systems.