MULTIDIMENSIONAL OPTIMAL CONTROL OF WIND TURBINE GENERATOR

Abstract

Small differences in wind speed can lead to huge differences in energy capture. In wind turbines, the received wind speed determines the power generation and output torque. However, as wind speed, direction and inflow angle vary across time and terrain, power systems need the ability to accurately predict wind power output from wind farms. Due to sudden variations in wind speed, direction and inflow angle, the value of the power output becomes a challenge that demands extensive study. In this thesis work, wind direction and pitch angle are used to control the performance of a wind turbine. The thesis is divided into two main parts. The first focuses on the dynamic analysis and control of a variable wind turbine rotor angle, which is represented by the rotor yaw angle and rotor angular deflection. Both the rotor yaw and rotor angular deflection control of horizontal and vertical axis wind turbine rotor are new control techniques. For dynamic analysis, rotor yaw and rotor angular deflection model techniques and experimental setup mechanisms are done step by step. The second part of the thesis describes the overall model of the multidimensional control of the wind turbine rotor. The model proposed in this research simulates the variable wind turbine rotor angle. The effects of changes in wind speed, direction and inflow angle on wind turbine generators are also considered in the proposed model, and an experimental setup is developed to evaluate acceptable changes in these factors. Three kinds of controllers were chosen to improve system stability: an integral plus pole placement, an integral plus Linear Quadratic Regulator, and a Linear Quadratic Gaussian for each actuation direction of the rotor angle. The controllers outputs indicate robust control of the rotor angle actuators and power output. Furthermore, to demonstrate the differences in energy capture, two types of wind turbines are used fixed and variable wind turbine rotor angles. The findings of this thesis regarding the impact of inflow angle on wind turbines can be applied to improve energy capture, reduce fatigue load, increase product lifetime, and improve overall performance.