Research on Loads Control of Wind Turbine Based on Disturbance Accommodating Control

2012 ◽  
Vol 522 ◽  
pp. 838-841
Author(s):  
Guo Yu Hu ◽  
Wen Lei Sun ◽  
Ji Zhe Hai ◽  
Yan Xu
Keyword(s):  
Wind Turbine ◽  
State Space ◽  
High Speed ◽  
Control Design ◽  
Maximum Power ◽  
Pi Control ◽  
Low Speed ◽  
Pitch Control ◽  
Disturbance Accommodating Control ◽  
Simulation Results

This paper uses modern control based on DAC control to numerically simulate a 1.5MW wind turbine. Through linearized modeling of 1.5MW wind turbine, this paper illustrates state-space control design and simulation for a 1.5MW wind turbine. This paper emphasizes on the use of DAC control to alleviate loads when the turbine is operating at maximum power. Loads diagrams of 1.5MW wind turbine including generator, low-speed shaft and high-speed shaft are obtained. The simulation results show that the collective pitch control based on DAC has certain effects on load alleviation compared to PI control.

scholarly journals Vibration Reduction Strategy for Offshore Wind Turbines

2020 ◽  
Vol 10 (17) ◽  
pp. 6091
Author(s):  
Haoming Liu ◽  
Suxiang Yang ◽  
Wei Tian ◽  
Min Zhao ◽  
Xiaoling Yuan ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Wind Turbines ◽  
Reference Signal ◽  
Offshore Wind ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
Pitch Control ◽  
Simulation Results ◽  
Aerodynamic Torque

The operational environment of offshore wind turbines is much more complex than that of onshore wind turbines. Facing the persistent wind and wave forces, offshore wind turbines are prone to vibration problems, which are not conducive to their long-term operation. Under this background, first, how the wave affects the vibration characteristics of offshore wind turbines is analyzed. Based on the existing wave and wave load models, we analytically show that there exist fluctuating components related to the hydrodynamic frequency in the aerodynamic load and aerodynamic torque of offshore wind turbines. Simulation results based on a GH Bladed platform further validates the analysis. Second, in order to reduce the joint impacts of the wave, wind shear and tower shadow on the wind turbine, a variable pitch control method is proposed. The integrated tower top vibration acceleration signal is superimposed on the collective pitch reference signal, then the triple frequency (3P) fluctuating component of the wind turbine output power and the azimuth angle of each blade are converted into the pitch angle adjustment signal of each blade, which is superimposed on the collective pitch signal for individual pitch control. The simulation results show that the proposed pitch control strategy can effectively smooth the fluctuation of blade root flap-wise load caused by wind and wave, and significantly reduce the fluctuation of aerodynamic torque and output power of offshore wind turbines.

Individual Pitch Control for Wind Turbine Load Reduction Enhanced With Inter-Turbine Wake Modelling

2011 ◽  
Author(s):  
Zhongzhou Yang ◽  
Yaoyu Li ◽  
John E. Seem
Keyword(s):  
Wind Turbine ◽  
State Space ◽  
Wind Profile ◽  
State Space Models ◽  
Load Reduction ◽  
Pitch Control ◽  
Wake Interaction ◽  
Wake Model ◽  
Individual Pitch Control ◽  
Turbine Wake

Individual pitch control (IPC) for wind turbine load reduction in Region 3 operation is improved when wake interaction is considered. The Larsen wake model is applied for composing the rotor wind profile for downstream turbines under wake interaction. The wind profile of the turbine wake was generated by modifying the NREL’s TurbSim codes. The state-space models of wind turbine were obtained via linearization of wind turbine model available in the NREL’s aeroelastic design code FAST. In particular, in order to obtain more accurate state-space models, equivalent circular wind profile was generated so as to better determine the local pitch reference. Based on such models, IPC controllers were designed following the disturbance accommodating control (DAC) and periodic control framework. The simulation results showed that the turbine loads can be further reduced using the switching control scheme based on wake modeling, as compared with the generic DAC without wake consideration.

Mechatronic Design of Mobile Robots for Stable Obstacle Crossing at Low and High Speeds

2015 ◽  
pp. 567-630
Author(s):  
Jean-Christophe Fauroux ◽  
Frédéric Chapelle ◽  
Belhassen-Chedli Bouzgarrou ◽  
Philippe Vaslin ◽  
Mohamed Krid ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Mobile Robots ◽  
High Speed ◽  
Legged Locomotion ◽  
Improve Performance ◽  
Obstacle Crossing ◽  
Low Speed ◽  
Pitch Control ◽  
High Speeds ◽  
Hybrid Locomotion

This chapter presents recent mechatronics developments to create original terrestrial mobile robots capable of crossing obstacles and maintaining their stability on irregular grounds. Obstacle crossing is both considered at low and high speeds. The developed robots use wheeled propulsion, efficient on smooth grounds, and improve performance on irregular grounds with additional mobilities, bringing them closer to legged locomotion (hybrid locomotion). Two sections are dedicated to low speed obstacle crossing. Section two presents an original mobile robot combining four actuated wheels with an articulated frame to improve obstacle climbing. Section three extends this work to a new concept of modular poly-robot for agile transport of long payloads. The last two sections deal with high-speed motion. Section four describes new suspensions with four mobilities that maintain pitch stability of vehicles crossing obstacles at high speed. After the shock, section five demonstrates stable pitch control during ballistic phase by accelerating-braking the wheels in flight.

scholarly journals Active steering control based on preview theory for articulated heavy vehicles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252098
Author(s):  
Jie Tian ◽  
Qingkang Zeng ◽  
Peng Wang ◽  
Xiaoqing Wang
Keyword(s):  
High Speed ◽  
Single Point ◽  
Path Tracking ◽  
Lateral Stability ◽  
Steering Control ◽  
Linear Quadratic ◽  
Low Speed ◽  
Active Steering ◽  
Simulation Results ◽  
Active Steering Control

This paper investigates the active steering control of the tractor and the trailer for the articulated heavy vehicle (AHV) to improve its high-speed lateral stability and low-speed path following. The four-degree-of-freedom (4-DOF) single track dynamic model of the AHV with a front-wheel steered trailer is established. Considering that the road information at the driver’s focus is the most clear and those away from the focus blurred, a new kind controller based on the fractional calculus, i.e., a focus preview controller is designed to provide the steering input for the tractor to make it travel along the desired path. In addition, the active steering controllers based on the linear quadratic regulator (LQR) and single-point preview controller respectively are also proposed for the trailer. However, the latter is designed on the basis of the articulation angle between the tractor and trailer, inspired by the idea of the driver’s single-point preview controller. Finally, the single lane change maneuver and 90o turn maneuver are carried out. And the simulation results show that compared with the single-point preview controller, the new kind preview controller for the tractor can have good high speed maneuvering stability and low speed path tracking ability by adjusting the fractional order of the controller. On this basis, three different AHVs with the same tractor are simulated and the simulation results show that the AHV whose trailer adopts the single-point preview controller has better high-speed lateral stability and low-speed path tracking than the AHV whose trailer adopts the LQR controller.

Pitch Control for Wind Turbine in Yawed Inflow Condition

2014 ◽  
Author(s):  
Irving Paul Girsang ◽  
Jaspreet Singh Dhupia
Keyword(s):  
Wind Turbine ◽  
Bending Moments ◽  
Misalignment Angle ◽  
Operating Condition ◽  
Pitch Control ◽  
Angle Correction ◽  
Inflow Condition ◽  
Simulation Results ◽  
Blade Loads ◽  
Inflow Conditions

A wind turbine can experience yawed inflow with large yaw misalignment angle during faulty cases, such as faults in the yaw controller/drives, or during extreme atmospheric cases, such as thunderstorm downbursts. In such cases, it is risky for the turbine to continue operation because it is being exposed to large loads. Instead, it is recommended for the turbine to be transited to parking conditions. Currently, most turbine pitch controllers are designed without considering the yaw misalignment angle, correction of which is normally assigned to the yaw controller. This paper investigates the contribution of both a baseline and a proposed collective pitch controllers under yawed inflow conditions. The baseline controller tries to maintain the rated operating condition at an expense of large blade loads. On the contrary, simulation results show that the proposed controller slows down the turbine under the presence of yawed inflow, which helps to park the turbine and reduces the average blade root bending moments.

scholarly journals Performance Prediction and Validation of a Small-Capacity Twisted Savonius Wind Turbine

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1721 ◽  
Author(s):  
Hyeonmu Jang ◽  
Insu Paek ◽  
Seungjoo Kim ◽  
Deockjin Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Performance Test ◽  
Cfd Simulation ◽  
Power Production ◽  
Maximum Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Simulation Results

In this study, an off-grid–type small wind turbine for street lighting was designed and analyzed. Its performance was predicted using a computational fluid dynamics model. The proposed wind turbine has two blades with a radius of 0.29 m and a height of 1.30 m. Ansys Fluent, a commercial computational fluid dynamics solver, was used to predict the performance, and the k-omega SST model was used as the turbulence model. The simulation result revealed a tip-speed ratio of 0.54 with a maximum power coefficient, or an aerodynamic rotor efficiency of 0.17. A wind turbine was installed at a measurement site to validate the simulation, and a performance test was used to measure the power production. To compare the simulation results obtained from the CFD simulation with the measured electrical power performance, the efficiencies of the generator and the controller were measured using a motor-generator testbed. Also, the control strategy of the controller was found from the field test and applied to the simulation results. Comparing the results of the numerical simulation with the experiment, the maximum power-production error at the same wind speed was found to be 4.32%.

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.

Robust Control Design for Load Reduction on a Liberty Wind Turbine

2016 ◽  
Author(s):  
Daniel Ossmann ◽  
Julian Theis ◽  
Peter Seiler
Keyword(s):  
Wind Turbine ◽  
Control Strategies ◽  
Control Design ◽  
Load Reduction ◽  
University Of Minnesota ◽  
Control Loops ◽  
Pitch Control ◽  
Robust Control Design ◽  
And Performance ◽  
Utility Scale

The increasing size of modern wind turbines also increases the structural loads on the turbine caused by effects like turbulence or asymmetries in the inflowing wind field. Consequently, the use of advanced control algorithms for active load reduction has become a relevant part of current wind turbine control systems. In this paper, an H∞-norm optimal multivariable control design approach for an individual blade-pitch control law is presented. It reduces the structural loads both on the rotating and non-rotating parts of the turbine. Classical individual blade-pitch control strategies rely on single control loops with low bandwidth. The proposed approach makes it possible to use a higher bandwidth since it takes into account coupling at higher frequencies. A controller is designed for the utility-scale 2.5 MW Liberty research turbine operated by the University of Minnesota. Stability and performance are verified using a high-fidelity nonlinear benchmark model.

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