Improvement of Small Wind Turbine Control in the Transition Region

Abstract

Wind energy conversion systems are very challenging from the control system viewpoint. The control difficulties are even more challenging when wind turbines are able to operate at variable speed and variable pitch. The contribution of this work is focused on designing a combined controller that significantly alleviates the wind transient loads in the power tracking and power regulation modes as well as in the transition zone. In a previous work, the authors studied the applicability of different multivariable decoupling methodologies. The methodologies were tested in simulation and verified experimentally in a lab-scale wind turbine. It was demonstrated that multivariable control strategies achieve a good closed-loop response within the transition region, where the interaction level is greater. Nevertheless, although such controllers showed an acceptable performance in the power tracking (region II) and power regulation (region IV) zones, appreciable improvement was possible. To this end, the new proposed methodology employs a multivariable gain-scheduling controller with a static decoupling network for the transition region and monovariable controllers for the power tracking and power regulation regions. To make the transition between regions smoother, a gain scheduling block is incorporated into the multivariable controller. The proposed controller is experimentally compared with a standard switched controller in the lab-scale wind turbine. The experiments carried out suggest that the combination of the proposed multivariable strategy for the transition region to mitigate wind transient loads combined with two monovariable controllers, one dedicated to region II and other to region IV, provide better results than traditional switched control strategies.

Simulador on-line de turbinas eólicas mediante OpenFAST

“…Para vientos superiores que permitan generar la potencia nominal del generador, se modifica el ángulo de inclinación de las palas para disminuir el rendimiento aerodinámico y así mantener la potencia a dicho valor; el par electromagnético permanece fijo a su valor nominal (Lara et al, 2021). Entre estas dos regiones hay una zona de transición (Ruz, et al, 2020).…”

Wind Energy Potential in Urban Area: Case study Prishtina

“…More recently, the improvement in controlling small wind turbines in transition regions was studied in a journal article in 2020 (Ruz et al, 2020). Later at the beginning of 2021, a study was conducted on small wind turbines with Injection Molded Blades.…”

Adaptive Pitch Controller of a Large-Scale Wind Turbine Using Multi-Objective Optimization

“…This can be considered as choosing the solution with the shortest Euclidean distance from the ideal solution and the farthest Euclidean distance from the negative ideal solution [53]. The vector normalized value r ij (x) in (4) is used for the calculation of each weighted normalized value v ij according to (5).…”

“…From a control point of view, this can be achieved by operating wind turbines to generate energy captured from the wind more efficiently and to reduce their different structural loads improving their reliability [3]. Furthermore, the control system design of wind turbines is even more difficult due to the fact that wind turbines are non-linear systems with multiple outputs to be controlled and are subjected to intermittent and variable disturbances such as the wind direction and wind magnitude [4,5].…”