Research Article
ActiveandReactivePowerControlforWindTurbinesBasedDFIG
Using LQR Controller with Optimal Gain-Scheduling
Ashraf Radaideh , Mu’men Bodoor , and Ayman Al-Quraan
Electrical Power Engineering Department, Yarmouk University, Irbid, Jordan
Correspondence should be addressed to Ashraf Radaideh; a.radaideh@yu.edu.jo
Received 19 May 2021; Revised 24 July 2021; Accepted 15 September 2021; Published 6 October 2021
Academic Editor: François Vall´ ee
Copyright © 2021 Ashraf Radaideh et al. is is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
is paper proposes an optimal gain-scheduling for linear quadratic regulator (LQR) control framework to improve the per-
formance of wind turbines based Doubly Fed Induction Generator (DFIG). Active and reactive power decoupling is performed
using the field-oriented vector control which is used to simplify DFIG’s nonlinearity and derive a compact linearized state-space
model. e performance of the optimal controller represented by a linear quadratic regulator is further enhanced using the whale
optimization algorithm in a multiobjective optimization environment. Adaptiveness against wind speed variation is achieved in
an offline training process at a discretized wind speed domain. Lookup tables are used to store the optimal controller parameter
and called upon during the online implementation. e control framework further integrates the effects of pitch angle control
mechanism for active power ancillary services and possible improvements on reactive power support. e results of the proposed
control framework improve the overall performance of the system compared to the conventional PI controller. Comparison is
performed using the MATLAB Simulink platform.
1. Introduction
Electricity is one of the life necessities that made a quantum
leap in the world. Traditionally, electrical energy is primarily
produced using fossil fuel energy resources. However,
nowadays, the world is witnessing high production levels
from Renewable Energy Sources (RES). Wind turbines
(WTs) are among the leading and fast-growing technologies
over extended geographical areas. Worldwide, the total
installed capacity in 2019 is 650 GW. More than 93 GW is
installed in the year 2020 bringing the total installed capacity
to 743 GW despite the COVID-19 pandemic. is indicates
the importance and effectiveness of power production using
WTs [1].
Wind turbines are initially designed and operated with
fixed-speed induction machines to avoid additional costs
associated with power electronic converters. However, to
improve the conversion efficiency, the variable speed drive
system becomes more dominant. Doubly Fed Induction
Generator (DFIG) facilitates the variable speed feature
through a reduced size converter. is explains the widespread
use of DFIGs with wind turbines. DFIG’s stator is directly
connected to the grid at the nominal grid frequency and its
wound rotor through a bidirectional back-to-back voltage
source converters (VSC) but at variable frequency [2, 3].
In many countries, the integration of wind turbines with
the grid should follow strict codes and standards. Additional
features and capabilities traditionally overlooked have be-
come mandatory in new designs such as low voltage ride-
through, frequency regulation, and reactive power support.
Voltage dips result in large rotor currents due to the high
voltages induced in the rotor windings. erefore, DFIGs are
very sensitive to voltage sags. Large rotor currents may
destroy the Rotor Side Converter (RSC) if not appropriately
disconnected by the protection devices. Hence, the wind
turbine will be out of service during faulty conditions [4, 5].
1.1. Related Work. e history of DFIG development in
WTS and the different representations of modeling and
control techniques are provided in [5]. Modeling and
Hindawi
Journal of Electrical and Computer Engineering
Volume 2021, Article ID 1218236, 19 pages
https://doi.org/10.1155/2021/1218236