Fixed-Time Adaptive Robust Synchronization with a State Observer of Chaotic Support Structures for Offshore Wind Turbines

Pooyan Alinaghi Hosseinabadi,Ali Soltani Sharif Abadi,Saad Mekhilef,Hemanshu Roy Pota

doi:10.1007/s40313-021-00707-y

Pooyan Alinaghi Hosseinabadi, Ali Soltani Sharif Abadi + Show 2 more

Open Access

https://doi.org/10.1007/s40313-021-00707-y

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Abstract

The chaotic support structures for offshore wind turbines are often subjected to a severe environment. A robust control scheme needs to be considered to maintain them in a safe operational limit. Robust sliding mode control (SMC) scheme can provide an excellent robust controller against this severe and challenging environment for these chaotic structures. This paper proposes a novel fixed-time adaptive sliding mode control scheme with a state observer to synchronize chaotic support structures for offshore wind turbines in the presence of matched parametric uncertainties. The proposed controller is a new integration of adaptive control concept, SMC method, fixed-time stability concept and a state observer. A fixed-time stability concept is used to provide stability for the system within a presented time regardless of initial conditions. The adaptive concept is utilized to provide an online estimator of the uncertain upper bound. Also, a nonlinear observer is employed to provide an online estimator of an unmeasured state in the controller. Lyapunov stability theorem is used to analyze fixed-time stability of the system based on SMC methodology. The simulation results demonstrate that the proposed controller is able to ensure fixed-time synchronization along with providing precise means to estimate the unmeasured state as well as uncertainty upper bound.

Highlights

In recent decades, synchronization of different systems has been investigated for a variety of control goals
In (Ni et al 2016), a robust sliding mode control (SMC) scheme has been integrated with a fixed-time stability concept for chaos control in the power system
The above literature survey demonstrates that a notable fixed-time stability concept, SMC scheme, adaptive control approach, and state observer have been successfully designed and presented individually for different systems

Summary

Introduction

Synchronization of different systems has been investigated for a variety of control goals. In (Ni et al 2016), a robust SMC scheme has been integrated with a fixed-time stability concept for chaos control in the power system. The SMC scheme has been incorporated with an adaptive control concept to solve this issue by approximating the unknown parametric uncertainty bounds. The above literature survey demonstrates that a notable fixed-time stability concept, SMC scheme, adaptive control approach, and state observer have been successfully designed and presented individually for different systems. A novel FASMC scheme with a state observer is introduced for chaotic synchronization of two support structures for offshore wind turbines with matched parametric uncertainties. The fixed-time stability proof is obtained by utilizing only one candidate Lyapunov function by using designed control law, observer law, and adaptive law, simultaneously.

Mathematical Preliminaries

System Description

Problem Formulation

Controller Design by Using FASMC Scheme with a State Observer

Simulation Results and Discussion

Conclusion