A Sliding Mode Observer-Based Icing Detection and Estimation Scheme for Wind Turbines

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Maria Letizia Corradini ◽  
Gianluca Ippoliti ◽  
Giuseppe Orlando
Keyword(s):  
Renewable Energy ◽  
Wind Turbines ◽  
Sliding Mode ◽  
Angular Acceleration ◽  
Power Coefficient ◽  
Control Law ◽  
National Renewable Energy Laboratory ◽  
Robust Observer ◽  
Medium Speed ◽  
Estimation Scheme

In this paper, the problem of icing detection is considered for wind turbines (WTs) operating in medium speed wind region (region 2) and subject to a control law tracking the maximum delivery point of the power coefficient characteristic. Based on a robust observer of the rotor angular acceleration, rotor inertia is estimated in order to detect its eventual increase due to icing. Moreover, the observed value of rotor inertia can be potentially used for updating the controller parameters or to stop the turbine when icing is too severe. The proposed approach has been tested by intensive MatLab® simulations using the National Renewable Energy Laboratory 5 MW WT model.

A Preliminary Evaluation of a Multiple-Generator Drivetrain Configuration for Wind Turbines

2002 ◽  
Author(s):  
Jason R. Cotrell
Keyword(s):  
Renewable Energy ◽  
Wind Turbines ◽  
Recent Trend ◽  
Component Technology ◽  
Preliminary Evaluation ◽  
National Renewable Energy Laboratory ◽  
Energy Capture ◽  
Large Wind

The recent trend toward large wind turbines has led to very expensive gearboxes that hinder their feasibility. The gearboxes for these wind turbines are more expensive per kilowatt (kW) of rated power than for smaller turbines because the torque increases more quickly than the power when increasing the rotor diameter. Multiple-generator drivetrain configurations can reduce the drivetrain cost for large wind turbines while increasing the energy capture and reliability. The National Renewable Energy Laboratory (NREL) is reexamining the benefits of multiple-generator configurations through the Wind Partnership for Advanced Component Technology (WindPACT) program. This paper qualitatively compares a multiple-generator drivetrain configuration to a conventional drivetrain.

scholarly journals Robust fault estimation of a blade pitch and drivetrain system in wind turbine model

2020 ◽  
pp. 107754632092627
Author(s):  
Seyedeh Hamideh Sedigh Ziyabari ◽  
Mahdi Aliyari Shoorehdeli ◽  
Madjid Karimirad
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Sliding Mode ◽  
Sliding Mode Observer ◽  
Fault Estimation ◽  
Unknown Input ◽  
Unknown Input Observer ◽  
Reduced Order ◽  
Unknown Inputs ◽  
Estimation Scheme

In this article, a novel robust fault estimation scheme to ensure efficient and reliable operation of wind turbines has been presented. Wind turbines are complex systems with large flexible structures that work under very turbulent and unpredictable environmental conditions for a variable electrical grid. The proposed observer-based estimation scheme consists of a set of possible faults affecting the dynamics, sensors, and actuators of wind turbines. First, the pitch and drivetrain system faults occur simultaneously with process and sensor disturbances that are called unknown input signals. Second, through a series of coordinate transformations, the faulty subsystem is decoupled from the rest of the system. The first subsystem is affected by unknown inputs, and the second one is affected by faults. A reduced-order unknown input observer is designed to reconstruct states accurately, whereas a reduced-order sliding mode observer is designed for the second subsystem such that it is robust against unknown inputs and faults. Moreover, the reduced-order unknown input observer guarantees the asymptotic stability of the error dynamics using the Lyapunov theory method and completely removes unknown inputs; on the other hand, the reduced-order sliding mode observer is designed to reconstruct faults for the faulty subsystem accurately. Until now, authors only focused on an unknown input signal in the dynamics of the system, especially in nonlinear systems. The estimated fault will be adequate to accommodate the control loop, and sufficient conditions are developed to guarantee the stability of the state estimation error. In the next step, to figure the effectiveness of the proposed approach, a wind turbine benchmark system model is considered with faults and unknown inputs scenarios. The simulation results are used to validate the robustness of the proposed algorithms under noise conditions, and the results show that the algorithm could classify faults robustly.

scholarly journals Potential of Shrouded Micro Wind Turbine

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 340
Author(s):  
Kishor Sontakke ◽  
Samir Deshmukh ◽  
Sandip Patil
Keyword(s):  
Renewable Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Renewable Energy Sources ◽  
Turbine Blades ◽  
Weather Conditions ◽  
Power Coefficient ◽  
Solar Panels ◽  
Wind Speeds ◽  
Low Wind Speeds

The growing demand for electrical energy for industrial and domestic use, coupled with the limited amount of available fossil fuel reserves and its negative effects on the environment, have made it necessary to seek alternative and renewable energy sources. The use of renewable energy is promoted worldwide to be less dependent on conventional fuels and nuclear energy. Therefore research in the field is motivated to increase efficiency of renewable energy systems. This study aimed to study potential of micro wind turbine and velocity profile through shroud for low wind speeds. Although there is a greater inclination to use solar panels because of the local weather conditions, there are some practical implications that have place the use of solar panels in certain areas to an end. The biggest problem is panel stealing. Also, in some parts of the country the weather is more appropriate to apply wind turbines. Thus, this study paying attention on the design of a new concept to improve wind turbines to be appropriate for the low wind speeds in India. The concept involves the implementation of a concentrator and diffuser to a wind turbine, to increase the power coefficient. Although the wind turbine was not tested for starting speeds, the realization of the shroud should contribute to improved starting of the wind turbine at lower wind speeds. The configuration were not manufactured, but simulated with the use of a program to obtain the power production of the wind turbine over a range of wind speeds. These values were compared to measured results of an open wind turbine developed. The most important topic at hand when dealing with a shrouded wind turbine is to find out if the overall diameter or the blade diameter of the turbine should be the point of reference. As the wind turbine is situated in a shroud that has a larger diameter than the turbine blades, some researchers believe that the overall diameter should be used to calculate the efficiency. The benefits of shrouded wind turbines are discussed.

Nonlinear Speed Control of a Series DC Motor

2010 ◽  
Vol 33 ◽  
pp. 612-617
Author(s):  
Bing Xing Tang ◽  
Zhang Jun Wang
Keyword(s):  
Steady State ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Angular Acceleration ◽  
Speed Control ◽  
Dc Motor ◽  
Pi Controller ◽  
Control Law ◽  
Luenberger Observer ◽  
Mode Control

The nonlinear speed control problem of a series dc motor was considered. Based on the nonlinear model built by a hybrid method, in which the local stability was proved by the Lyapunov’s first method to ensure the meaningfulness of the identification of the steady-state-about plant parameters, a sliding-mode control law, with a load torque Luenberger observer and an angular acceleration estimator, was derived theoretically, which effectiveness demonstrated by simulations and experiments. In order to reduce the steady-state error caused by the discrete implementation, a modified sliding-mode control with an auxiliary PI controller was proposed. The experiments show that the modified sliding-mode control law is superior to the PID regulator and the ordinary sliding-mode control law.

scholarly journals Wind Tunnel Testing of an Optimal Feedback/feedfoward Control Law for Wind Turbines

2020 ◽  
Vol 53 (2) ◽  
pp. 12638-12643
Author(s):  
Michael Sinner ◽  
Vlaho Petrović ◽  
Frederik Berger ◽  
Lars Neuhaus ◽  
Martin Kühn ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbines ◽  
Control Law ◽  
Wind Tunnel Testing ◽  
Optimal Feedback ◽  
Tunnel Testing

scholarly journals A Robust Observer—Based Adaptive Control of Second—Order Systems with Input Saturation via Dead-Zone Lyapunov Functions

Computation ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 82
Author(s):  
Alejandro Rincón ◽  
Gloria M. Restrepo ◽  
Fredy E. Hoyos
Keyword(s):  
Lyapunov Functions ◽  
Dead Zone ◽  
Tracking Error ◽  
Input Saturation ◽  
Chemical Reactor ◽  
Second Order ◽  
Control Law ◽  
Compact Set ◽  
State Variables ◽  
Robust Observer

In this study, a novel robust observer-based adaptive controller was formulated for systems represented by second-order input–output dynamics with unknown second state, and it was applied to concentration tracking in a chemical reactor. By using dead-zone Lyapunov functions and adaptive backstepping method, an improved control law was derived, exhibiting faster response to changes in the output tracking error while avoiding input chattering and providing robustness to uncertain model terms. Moreover, a state observer was formulated for estimating the unknown state. The main contributions with respect to closely related designs are (i) the control law, the update law and the observer equations involve no discontinuous signals; (ii) it is guaranteed that the developed controller leads to the convergence of the tracking error to a compact set whose width is user-defined, and it does not depend on upper bounds of model terms, state variables or disturbances; and (iii) the control law exhibits a fast response to changes in the tracking error, whereas the control effort can be reduced through the controller parameters. Finally, the effectiveness of the developed controller is illustrated by the simulation of concentration tracking in a stirred chemical reactor.

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