Linear Parameter Varying Power Regulation of Variable Speed Pitch Manipulated Wind Turbine in the Full Load Regime

TL;DR

This paper presents a Linear Parameter Varying (LPV) H_inf control strategy for wind turbines to improve power regulation and reduce mechanical stresses under turbulent wind conditions, outperforming PI-Fuzzy controllers.

Contribution

The paper introduces a novel LPV H_inf control approach for wind turbine power regulation that handles high turbulence and wind variability more effectively than existing methods.

Findings

LPV controller reduces power fluctuations under turbulent winds.

LPV control improves transient and steady-state performance.

Mechanical loads are significantly decreased with LPV control.

Abstract

In a wind energy conversion system (WECS), changing the pitch angle of the wind turbine blades is a typical practice to regulate the electrical power generation in the full-load regime. Due to the turbulent nature of the wind and the large variations of the mean wind speed during the day, the rotary elements of the WECS are subjected to significant mechanical stresses and fatigue, resulting in conceivably mechanical failures and higher maintenance costs. Consequently, it is imperative to design a control system capable of handling continuous wind changes. In this work, Linear Parameter Varying (LPV) H_inf controller is used to cope with wind variations and turbulent winds with a turbulence intensity greater than 10%. The proposed controller is designed to regulate the rotational rotor speed and generator torque, thus, regulating the output power via pitch angle manipulations. In addition, a PI-Fuzzy control system is designed to be compared with the proposed control system. The closed-loop simulations of both controllers established the robustness and stability of the suggested LPV controller under large wind velocity variations, with minute power fluctuations compared to the PI-Fuzzy controller. The results show that in the presence of turbulent wind speed variations, the proposed LPV controller achieves improved transient and steady-state performance along with reduced mechanical loads in the above-rated wind speed region.