Advanced Dispatching of a Wind Farm Based on Doubly Fed Induction Generators for the Improvement of LVRT Capability by the ADRC Approach

Abstract

This paper aims to explore a viable monitoring and management of active and reactive powers for a large-scale wind farm based on Doubly- Fed Induction Generators (DFIG) considering the volt- age Fault-Ride-Through capability (FRT), especially Low-Voltage-Ride-Through (LVRT) capability by using a new control strategy, known as Active Disturbance Rejection Control. This strategy uses real-time estima- tion and compensation of the generalized "total" dis- turbance before it affects the system. The wind farm supervisory unit is used to coordinate the control of the powers production by the entire wind farm, which must take into account the couplings between each wind gen- erator while producing the individual power commands. The turbine control units (local supervisory units) send the appropriate power references depending on the sit- uation. This can be to produce the maximum power, to manage the active and reactive power given by the Transmission System Operator (TSO) or to meet the requirements of the grid code (LVRT capacity). How- ever, to ensure the dispatching of the references of the active and reactive powers over the all wind generators of the wind farm and to satisfy the security of the power grid, we utilized mean of the proportional distribution algorithm. The effectiveness of the proposed supervisory approach and control strategies are tested and vali- dated through a multiples scenarios of simulations that are made under the MATLAB/Simulink Environment. The results obtained have demonstrated the efficiency and robustness of the control methods, and also the fact that they guarantee good performance and safety of the integration of wind farms into the grid while complying with the requirements of the grid code during power system faults.