scholarly journals Disturbance Accommodating Control Design for Wind Turbines Using Solvability Conditions

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Na Wang ◽  
Alan D. Wright ◽  
Mark J. Balas
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Kronecker Product ◽  
Solvability Condition ◽  
Control Design ◽  
Rotor Speed ◽  
Solvability Conditions ◽  
Speed Regulation ◽  
Disturbance Accommodating Control

In this paper, solvability conditions for disturbance accommodating control (DAC) have been discussed and applied on wind turbine controller design in above-rated wind speed to regulate rotor speed and to mitigate turbine structural loads. An asymptotically stabilizing DAC controller with disturbance impact on the wind turbine being totally canceled out can be found if certain conditions are fulfilled. Designing a rotor speed regulation controller without steady-state error is important for applying linear control methodology such as DAC on wind turbines. Therefore, solvability conditions of DAC without steady-state error are attractive and can be taken as examples when designing a multitask turbine controller. DAC controllers solved via Moore–Penrose Pseudoinverse and the Kronecker product are discussed, and solvability conditions of using them are given. Additionally, a new solvability condition based on inverting the feed-through D term is proposed for the sake of reducing computational burden in the Kronecker product. Applications of designing collective pitch and independent pitch controllers based on DAC are presented. Recommendations of designing a DAC-based wind turbine controller are given. A DAC controller motivated by the proposed solvability condition that utilizes the inverse of feed-through D term is developed to mitigate the blade flapwise once-per-revolution bending moment together with a standard proportional integral controller in the control loop to assist rotor speed regulation. Simulation studies verify the discussed solvability conditions of DAC and show the effectiveness of the proposed DAC control design methodology.

scholarly journals Fault Tolerant Control of Internal Faults in Wind Turbine: Case Study of Gearbox Efficiency Decrease

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Younes Ait El Maati ◽  
Lhoussain El Bahir ◽  
Khalid Faitah
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Operating Point ◽  
Rotor Speed ◽  
Integral Term ◽  
Internal Faults

This paper presents a method to control the rotor speed of wind turbines in presence of gearbox efficiency fault. This kind of faults happens due to lack of lubrication. It affects the dynamic of the principal shaft and thus the rotor speed. The principle of the fault tolerant control is to find a bloc that equalizes the dynamics of the healthy and faulty situations. The effectiveness decrease impacts on not only the dynamics but also the steady state value of the rotor speed. The last reason makes it mandatory to add an integral term on the steady state error to cancel the residual between the measured and operating point rotor speed. The convergence of the method is proven with respect to the rotor parameters and its effectiveness is evaluated through the rotor speed.

scholarly journals Design of Supervisory Control for Speed Control of Wind Turbine using Torque-Control Method Based on Buck Converter

2020 ◽  
Vol 190 ◽  
pp. 00019
Author(s):  
Katherin Indriawati ◽  
Choirul Mufit ◽  
Andi Rahmadiansah
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Supervisory Control ◽  
Control Method ◽  
Speed Control ◽  
Buck Converter ◽  
Torque Control ◽  
Control Mode ◽  
Rotor Speed ◽  
Integral Control

The variation of wind speed causes the electric power generated by the turbine also varies. To obtain maximum power, the rotor speed of wind turbines must be optimally rated. The rotor speed can be controlled by manipulating the torque from the generator; this method is called Torque Control. In that case, a DC-DC converter is needed as the control actuator. In this study, a buck converter-based supervisory control design was performed on the Horizontal-axis wind turbines (HAWT). Supervisory control is composed of two control loops arranged in cascade, and there is a formula algorithm as the supervisory level. The primary loop uses proportional control mode with a proportional gain of 0.3, whereas in the secondary loop using proportional-integral control mode with a proportional gain of 5.2 and an integral gain of 0.1. The Supervisory control has been implemented successfully and resulted in an average increase in turbine power of 4.1 % at 5 m s–1 and 10.58 % at 6 m s–1 and 11.65 % at 7 m s–1, compared to wind turbine systems without speed control.

Disturbance Observer-Based Pitch Control of Wind Turbines for Enhanced Speed Regulation

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Yuan Yuan ◽  
X. Chen ◽  
J. Tang
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Disturbance Observer ◽  
Low Frequency ◽  
Time Varying ◽  
Control Loop ◽  
Wind Speeds ◽  
Speed Regulation ◽  
Guaranteed Stability ◽  
Linearized Model

Time-varying unknown wind disturbances influence significantly the dynamics of wind turbines. In this research, we formulate a disturbance observer (DOB) structure that is added to a proportional-integral-derivative (PID) feedback controller, aiming at asymptotically rejecting disturbances to wind turbines at above-rated wind speeds. Specifically, our objective is to maintain a constant output power and achieve better generator speed regulation when a wind turbine is operated under time-varying and turbulent wind conditions. The fundamental idea of DOB control is to conduct internal model-based observation and cancelation of disturbances directly using an inner feedback control loop. While the outer-loop PID controller provides the basic capability of suppressing disturbance effects with guaranteed stability, the inner-loop disturbance observer is designed to yield further disturbance rejection in the low frequency region. The DOB controller can be built as an on–off loop, that is, independent of the original control loop, which makes it easy to be implemented and validated in existing wind turbines. The proposed algorithm is applied to both linearized and nonlinear National Renewable Energy Laboratory (NREL) offshore 5-MW baseline wind turbine models. In order to deal with the mismatch between the linearized model and the nonlinear turbine, an extra compensator is proposed to enhance the robustness of augmented controller. The application of the augmented DOB pitch controller demonstrates enhanced power and speed regulations in the above-rated region for both linearized and nonlinear plant models.

Dynamic Optimization of Drivetrain Gear Ratio to Maximize Wind Turbine Power Generation—Part 2: Control Design

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
John F. Hall ◽  
Dongmei Chen
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Electrical Power ◽  
Control Design ◽  
Gear Ratio ◽  
Small Wind Turbines ◽  
Full Load Operation ◽  
Wind Profiles ◽  
Turbine Model

The cost of electrical power produced by small wind turbines impedes the use of this technology, which can otherwise provide power to millions of homes in rural regions worldwide. To encourage their use, small wind turbines must capture wind energy more effectively while avoiding increased equipment costs. A variable ratio gearbox (VRG) can provide this capability to the simple fixed-speed wind turbine through discrete operating speeds. This is the second of a two-part publication that focuses on the control of a VRG-enabled wind turbine. The first part presented a 100 kW fixed speed, wind turbine model, and a method for manipulating the VRG and mechanical brake to achieve full load operation. In this study, an optimal control algorithm is developed to maximize the power production in light of the limited brake pad life. Recorded wind data are used to develop a customized control design that is specific to a given site. Three decision-making modules interact with the wind turbine model developed in Part 1 to create possible VRG gear ratio (GR) combinations. Dynamic programming is applied to select the optimal combination and establish the operating protocol. The technique is performed on 20 different wind profiles. The results suggest an increase in wind energy production of nearly 10%.

The Effect of Distributed Roughness on the Power Performance of Wind Turbines

2010 ◽  
Author(s):  
G. Pechlivanoglou ◽  
S. Fuehr ◽  
C. N. Nayeri ◽  
C. O. Paschereit
Keyword(s):  
Steady State ◽  
Wind Tunnel ◽  
Numerical Simulations ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Power Production ◽  
Aerodynamic Performance ◽  
Power Performance ◽  
Turbine Performance ◽  
Wind Tunnel Measurements

The effects of distributed roughness on wind turbines are extensively investigated in this paper. The sources of roughness are identified and analyzed and their effects on airfoil are estimated from simulations and measured with wind tunnel measurements. In addition to the environmental and manufacturing induced roughness, several forms of roughness-related shape deviations are investigated and their effects on the aerodynamic performance of airfoils is qualitatively predicted through numerical simulations. The actual effects of roughness on wind turbine performance are also presented through power production measurements of wind turbines installed in sandy environments. These measurements are correlated with simulated power predictions, utilizing a steady state BEM code.

scholarly journals Research of Power Control for Grid-connected Wind Turbine with Differential Speed Regulation

2018 ◽  
Author(s):  
Su Rui ◽  
Zhang Huan ◽  
Wang Fujun ◽  
Li Gangjun
Keyword(s):  
Wind Speed ◽  
Power Control ◽  
Wind Turbine ◽  
Control Method ◽  
Frequency Converter ◽  
Gear Train ◽  
Speed Ratio ◽  
Rotor Speed ◽  
Speed Regulation ◽  
Differential Speed

The differential gear train and speed regulating motor constitute the variable ratio transmission for grid-connected wind turbine with differential speed regulation. The synchronous generator in the system can accessing the power grid without frequency converter. The transmission can realize the mode of variable speed constant frequency that the wind rotor speed is varying and the generator rotor speed is constant. The power control method is studied under the different wind speed which is lower or higher than rated wind speed with using the relational expression of utilization rate of wind energy Cp, pitch angle β and the tip speed ratio λ. The SIMULINK software is used to build the 1500 kW wind turbine model with differential speed regulation. Some different wind speed is made as input. The feasibility of power control method for grid-connected wind turbine with differential speed regulation is verified by the comparison between the simulation results and the theoretical value of the key parameters.

scholarly journals Simulating the Speed control System of Wind Turbines Using MATLAB Software

2020 ◽  
Vol 4 (2) ◽  
pp. 1-6
Author(s):  
Seyed Mojtaba Hosseini Bafoghi ◽  
Hamidreza Khezri
Keyword(s):  
Mathematical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Pid Controller ◽  
Electrical Energy ◽  
Induction Generator ◽  
Rotor Speed ◽  
Output Frequency ◽  
Static Loads ◽  
Simulation Results

In this paper, a mathematical method is proposed to control the output frequency of a self-excited induction generator using wind turbines and static loads. A dynamic model of the wind turbine is implemented to model the Connections and fittings of the wind turbine to convert the wing energy to electrical energy. Also a PID controller system is proposed to control the rotor speed of the wind turbine. The proposed mathematical model is developed in MATLAB-Simulink software. The simulation results showed that the developed controller can be used to control the wind turbine velocity.

Optimal Pitch Control Design With Disturbance Rejection for the Controls Advanced Research Turbine

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
David Wenzhong Gao ◽  
Xiao Wang ◽  
Jianhui Wang ◽  
Tianqi Gao ◽  
Margareta Stefanovic ◽  
...  
Keyword(s):  
Steady State ◽  
Wind Turbine ◽  
Feedforward Control ◽  
State Regulation ◽  
Rotor Speed ◽  
Coupled Modes ◽  
Control Approach ◽  
Pitch Control ◽  
Model Based ◽  
The Impact

Advanced and model-based control techniques have become prevalent in modern wind turbine controls in the past decade. These methods are more attractive compared to the commonly used proportional-integral-derivative (PID) controller, as the turbine structural flexibility is increased with multiple and coupled modes. The disturbance accommodating control (DAC) is an effective turbine control approach for the above-rated wind speed region. DAC augments the turbine state-space model with a predefined disturbance waveform model, based on which the controller reduces the impact of wind disturbances on the system output (e.g., rotor speed). However, DAC cannot completely reject the wind disturbance in certain situations, and this results in steady-state regulation errors in the turbine rotor speed and electric power. In this paper, we propose a novel wind turbine pitch control using optimal control theory. The obtained feedback and feedforward control terms function to stabilize the turbine system and reject wind disturbances, respectively, derived systematically based on the Hamilton–Jacobi–Bellman (HJB) equation. Simulation results show that the proposed method achieves desired rotor speed regulation with significantly reduced steady-state errors under turbulent winds, which is simulated on the model of the three-bladed controls advanced research turbine (CART3) using the FAST code.

scholarly journals Grid-Connected Control of Wind Turbine with Differential Speed Regulation Based on Fuzzy Decision Makings

2019 ◽  
Vol 13 (9) ◽  
pp. 10
Author(s):  
Xiaoming Rui ◽  
Lubing Xie ◽  
Xiaochao Fan ◽  
Changkai Xiu
Keyword(s):  
Control System ◽  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Fuzzy Controller ◽  
Control Function ◽  
Load Condition ◽  
Speed Regulation ◽  
Set Up ◽  
Differential Speed

To solve the problem of grid-connected control of differential speed-regulating wind turbines, the wind turbine, transmission chain, speed-regulating motor, and generator model of the unit are constructed using the MATLAB/Simulink platform. The differential speed-regulating control system is designed on the basis of slip-frequency and fuzzy control theories. The speed control function and characteristics on maximum power tracing of wind turbine is tested via simulation. Meanwhile, the experimental bench for the differential speed-regulating wind power system is set up. Test results indicate that the generator speed is controlled by speed-regulating motor with output voltage and frequency that are approximately synchronized with those of power grid under idle load condition. The maximum wind-power utilization coefficient is maintained by fuzzy controller under the rated wind speed. Thus, the accuracy and efficiency of the designed control system is proven and provide important implications for further investigations on the grid-connected control of wind turbines with differential speed regulation.

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