A Disturbance Observer Based Sliding Mode Control for Variable Speed Wind Turbine

Abstract

This paper shows the effectiveness of disturbance observer (DO) based sliding mode control (SMC) scheme as compared to traditional SMC. Both the methods are simulated for variable speed wind turbine (VSWT) to ensure asymptotic tracking of rotor speed even in the presence of disturbances. Two mass model of VSWT is derived which includes the damping effect of the rotor's blade and generator. The stiffness and damping effect of low-speed shaft are also taken into account while modelling the system. The dynamic model of VSWT contains both matched and mismatched uncertainties. Traditional SMC can only attenuate the effect of match uncertainties. The DO-based SMC overcomes the drawback of traditional SMC by attenuating mismatch uncertainties. In the proposed approach, a sliding manifold is chosen based on the estimation of an uncertain parameter (aerodynamic torque), which drives the system's states to equilibrium point in a finite time.

Keywords:

• Aerodynamics
• Disturbance observer
• Robustness
• Sliding mode control
• Wind turbine
• Uncertainties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Ateeq ur Rehman

Ateeq ur Rehman His research interests include nonlinear, linear and robust control of dynamic systems. He completed masters in electrical engineering from COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan. Currently, he is enrolled in PhD Systems Engineering program at Pakistan Institute of Engineering & Applied Sciences. Email: [email protected]

Nihad Ali

Nihad Ali was born in Mardan, Pakistan, in 1992. He has currently completed his masters in electrical engineering from COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan. His research interests include nonlinear, linear and robust control of dynamic systems. Email: [email protected]

Owais Khan

Owais Khan was born in Swabi, Pakistan, in 1989. He completed masters in electrical engineering from COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan. Currently, he is enrolled in PhD Systems Engineering program at Pakistan Institute of Engineering & Applied Sciences. His research interests include fault diagnosis and tolerance, nonlinear and robust control of dynamic systems, optimization, etc. He is an author of one ISI Indexed Journal article and one IEEE Conference article. Email: [email protected]

Mahmood Pervaiz

Mahmood Pervaiz was born in Rawalpindi, Pakistan, in 1948. He has worked for over 15 years in Schlumberger and National Institute of Electronics, Pakistan. Since 2002, he is PhD in electrical engineering with specialization in control systems from COMSATS Institute of Information Technology Islamabad, Pakistan. He is working as senior specialist in Electronics at Electrical Engineering Department at CIIT, Islamabad, Pakistan. He is a renowned authority on nonlinear and robust control of physical systems with a focus on system modelling, identification and optimization. Email: [email protected]