Disturbance observer‐based integral sliding mode control for wind energy conversion systems

Abstract

Recently, wind power production has been under the focus in generating power and became one of the main sources of alternative energy. Generating of maximum power from wind energy conversion system (WECS) requires accurate estimation of aerodynamic torque and uncertainties presented in the system. The current paper proposed the generalized high‐order disturbance observer (GHODO) with integral sliding mode control (ISMC) for extraction of maximum power via variable speed wind turbine by accurate estimation of wind speed. The assumption in previous works that considers the aerodynamic torque as slow‐varying is not applicable for the real system. Therefore, the high‐order disturbance observers were designed for precise estimation of uncertainties with fast‐changing behavior. A robust control system was designed to control the speed of the rotor at the optimal speed ratio. The obtained simulation results have shown the better performance characteristics than conventional linear quadratic regulator (LQR) approach. The stability of the proposed algorithm was proven by Lyapunov stability anaysis. Simulations results were obtained in Matlab/Simulink environment.

SDRE-Based Integral Sliding Mode Control for Wind Energy Conversion Systems

“…The performance has been assessed by percentage of average absolute angular shaft speed tracking error |ω| and percentage of average absolute electromagnetic torque error T e function of the quadrature current i q . In the Table 4, the proposed SDRE-based ISMC control system with N = 1 and N = 2 have been assessed and compared with other advanced control methods namely, LQR-based optimal control method published in [4], linear output feedback-based ISMC method [10], and switching output feedback control law based 1 st order SMC method [29]. It should be noted that ISMC control method with N = 0 is same as linear output feedback-based ISMC proposed in [10].…”

“…The latter causes increasing the price of whole system. Also, for class of nonlinear systems, modified hybrid integral SMC and second order ISMC controllers have been proposed to control inverted pendulum [37], the attitude control of the spacecraft [38], anthromorphic industrial robot manipulator [39], ISMC control law in the studies [10], [40] consists the linear optimal feedback control as nominal part and continuously approximated discontinuous switching function. However, the nominal control part cannot guarantee better approximation because it does not take into account nonlinear terms of the WECS.…”

Maximum power tracking of variable‐speed wind energy conversion systems based on a near‐optimal servomechanism control system

“…In order to combat these challenges nonlinear control methods based as sliding mode control (SMC), direct torque control (DTC), fuzzy control (FC), intelligent control (IC), model predictive control (MPC) have been designed for PMSG-based WECS. [18][19][20][21][22][23][24] Integral SMC has ability to eliminate reaching phase with LQR-based linear output feedback controller 19 and conventional state-dependent Riccatti equation (SDRE)-based nonlinear output controller 18 for guaranteeing closed-loop stability. The so-called chattering phenomenon in the sliding surfaces have been reduced by continuous approximation, but in Reference 21 second order SMC controller has been utilized to eliminate chattering.…”

High Order Disturbance Observer Based PI-PI Control System With Tracking Anti-Windup Technique for Improvement of Transient Performance of PMSM

“…On the other hand, comparing with induction motors, it has higher efficiency [1]. However, it has been reported [2]- [7], that the PMSMs with nonlinear multivariable structure, external disturbance, noise, and uncertainties, cannot be controlled precisely [8], [9]. Direct torque control (DTC) is one of the approaches to simplify the control system in PMSM control applications.…”