Enhanced Polynomial Interpolation-Based SVPWM Control for A PMSG Horizontal Axis Wind Turbine under Varying Operating Conditions

Abstract

This study presents an improved control strategy for a 5.5 kW horizontal-axis wind turbine. The control schemes are initially developed using state-feedback and backstepping techniques, then improved using polynomial interpolation technique. The control objectives were defined according to distinct wind speed regions. The interpolation-based approach is proposed to determine the pitch angle variations as a function of wind speed, ensuring maximum power extraction even under abrupt wind fluctuations. A second interpolation is employed to compute optimal voltage references for different wind speeds, enabling fast and effective system response under rapidly varying wind conditions. These voltage references are implemented using space vector pulse width modulation (SVPWM), which is well known for its superior performance in terms of energy quality, noise reduction, and harmonic distortion, compared to other modulation techniques. The proposed control strategy mitigates power peaks and irregular transient behavior during transitions between operating regions. Unlike most of the works found in the literature, the proposed strategy is evaluated across all four operating zones rather than focusing only on maximum power point tracking (MPPT) or limiting the maximum extracted power. Additionally, wind gusts are incorporated into the simulation tests to reflect more realistic operating conditions. The simulation results demonstrate that the proposed approach effectively manages wind gusts and operating-zone transitions with stable and robust performances across all four regions.