This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

A copy of Guangbo jiemu bao [Broadcast Program Report] was being passed from hand to hand among a group of young people eager to be the first to read the article introducing the program "What Is Revolutionary Love?" It said: "… Young friends, you are certainly very concerned about this problem'. So, we would like you to meet the young women workers Meng Xiaoyu and Meng Yamei and the older cadre Miss Feng. They are the three leading characters in the short story ‘The Place of Love.’ Through the description of the love lives of these three, the story induces us to think deeply about two questions that merit further examination.

This is How the Discussion Started

FAST User's Guide

This paper discusses about integrating renewable energy sources into the smart power grid through industrial electronics. This paper discusses photovoltaic power, wind energy conversion, hybrid energy systems, and tidal energy conversion.

Future Energy Systems: Integrating Renewable Energy Sources into the Smart Power Grid Through Industrial Electronics

Energy is an essential ingredient of socio-economic development and economic growth. Renewable energy sources like wind energy is indigenous and can help in reducing the dependency on fossil fuels. Wind is the indirect form of solar energy and is always being replenished by the sun. Wind is caused by differential heating of the earth's surface by the sun. It has been estimated that roughly 10 million MW of energy are continuously available in the earth's wind. Wind energy provides a variable and environmental friendly option and national energy security at a time when decreasing global reserves of fossil fuels threatens the long-term sustainability of global economy. This paper reviews the wind resources assessment models, site selection models and aerodynamic models including wake effect. The different existing performance and reliability evaluation models, various problems related to wind turbine components (blade, gearbox, generator and transformer) and grid for wind energy system have been discussed. This paper also reviews different techniques and loads for design, control systems and economics of wind energy conversion system.

A review of wind energy technologies

We review the objectives and techniques used in the control of horizontal axis wind turbines at the individual turbine level, where controls are applied to the turbine blade pitch and generator. The turbine system is modeled as a flexible structure operating in the presence of turbulent wind disturbances. Some overview of the various stages of turbine operation and control strategies used to maximize energy capture in below rated wind speeds is given, but emphasis is on control to alleviate loads when the turbine is operating at maximum power. After reviewing basic turbine control objectives, we provide an overview of the common basic linear control approaches and then describe more advanced control architectures and why they may provide significant advantages.

/pdf/control-of-wind-turbines-past-present-and-future-2i0li1bgsp.pdf

Control of wind turbines: Past, present, and future

An adaptive feedforward controller based on a filtered-x recursive least square (FX-RLS) algorithm and a non-adaptive feedforward controller based on a zero-phase-error tracking control (ZPETC) technique have been designed to augment a collective pitch proportional-integral (PI) feedback controller for wind turbine rotor speed regulation and component load reduction when the wind turbine is operating above rated wind speed The inputs to the adaptive feedforward controller include measurements of the rotor speed error and the incoming wind speed, where wind speed would be provided by a commercial light detection and ranging (LIDAR) system Simulation results are based on comparison with a PI feedback only controller Simulations show that augmenting the baseline PI feedback control with ZPETC feedforward control improves the blade loads but worsens the tower loads The FX-RLS feedforward algorithm gives better performance than both the baseline PI feedback and the ZPETC feedforward in both tower (fore-aft and side-to-side) and blade (flapwise and edgewise) bending moment mitigation Even with realistic 1 Hz LIDAR data update rate, the FX-RLS feedforward strategy can effectively mitigate the tower and blade bending moment while providing better rotor speed tracking and only a small energy drop

FX-RLS-Based Feedforward Control for LIDAR-Enabled Wind Turbine Load Mitigation

In this paper, a nacelle-mounted lidar was used to improve the yaw alignment of an experimental wind turbine. Using lidar-recorded data during normal operation, an error correction value for the nacelle vane wind direction measurement used in the yaw controller was determined. A field test was then conducted in which the turbine was operated with and without the correction applied to the yaw controller. Results demonstrated a significant increase in power capture. In addition, the study includes analysis on the impacts on loading of applying this yaw correction. The study demonstrates a successful application in field testing of using a nacelle-mounted lidar to improve turbine performance.

https://iopscience.iop.org/article/10.1088/1742-6596/524/1/012002/pdf

Field-test results using a nacelle-mounted lidar for improving wind turbine power capture by reducing yaw misalignment

Pitching the individual blades of a horizontal-axis wind turbine allows control of asymmetric aerodynamic loads, which in turn influences structural loads in the nonrotating frame such as tower side-side bending. These loads are not easily controlled by traditional collective pitch algorithms. This paper presents the design of individual pitch control systems for implementation on the Controls Advanced Research Turbine (CART) in Colorado to verify controller performance for load attenuation. The control designs are based on linear time-periodic state-space models of the turbine and use optimal control methods for gain calculation. Comparisons are made between new individual pitch, new collective pitch, and baseline controller performance in both above rated and below rated wind conditions. Results from simulations show the potential of individual pitch to reduce tower side-side fatigue damage in above rated wind speeds (by 70% compared to baseline control) but with no improvement over collective pitch in below rated wind speeds. Fatigue load reductions in tower fore-aft, shaft torsion, and blade flap are also observed. From 13h of field testing, both collective and individual pitch controllers achieve a reduction in fatigue damage. However, the superior performance of individual pitch control observed in simulation was not verified by the field test results.

Individual Blade Pitch Control for the Controls Advanced Research Turbine "CART…

https://www.tpbin.com/Uploads/Subjects/f45646b1-fe82-4026-9021-364b880307b7.pdf

Alan Wright

Papers

Control of wind turbines: Past, present, and future

FX-RLS-Based Feedforward Control for LIDAR-Enabled Wind Turbine Load Mitigation

Field-test results using a nacelle-mounted lidar for improving wind turbine power capture by reducing yaw misalignment

Individual Blade Pitch Control for the Controls Advanced Research Turbine "CART…

Adding feedforward blade pitch control to standard feedback controllers for load mitigation in wind turbines