Zeitschriftenartikel: „Blade pitch control“

1

Chen, Lei, und Zhen Luo. „The Realization of Individual Pitch Control“. Applied Mechanics and Materials 291-294 (Februar 2013): 477–80. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.477.

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This paper describes the classical individual pitch control algorithm. Firstly, transform the out-of-plane bending moment of each blade in the rotational coordinate to the hub loads proportional to the tilt and yaw moment in the fixed coordinate. Secondly, design the PI controllers to minimize the load. And then attach the increment pitch angle to the collective one. Simulations in the Bladed show that the individual pitch control can minimize the loads not only in hub tilt and yaw, but also in blade root.

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Samani, Arash E., Jeroen D. M. De Kooning, Nezmin Kayedpour, Narender Singh und Lieven Vandevelde. „The Impact of Pitch-To-Stall and Pitch-To-Feather Control on the Structural Loads and the Pitch Mechanism of a Wind Turbine“. Energies 13, Nr. 17 (01.09.2020): 4503. http://dx.doi.org/10.3390/en13174503.

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This article investigates the impact of the pitch-to-stall and pitch-to-feather control concepts on horizontal axis wind turbines (HAWTs) with different blade designs. Pitch-to-feather control is widely used to limit the power output of wind turbines in high wind speed conditions. However, stall control has not been taken forward in the industry because of the low predictability of stalled rotor aerodynamics. Despite this drawback, this article investigates the possible advantages of this control concept when compared to pitch-to-feather control with an emphasis on the control performance and its impact on the pitch mechanism and structural loads. In this study, three HAWTs with different blade designs, i.e., untwisted, stall-regulated, and pitch-regulated blades, are investigated. The control system is validated in both uniform and turbulent wind speed. The results show that pitch-to-stall control enhances the constant power control for wind turbines with untwisted and stall-regulated blade designs. Stall control alleviates the fore-aft tower loading and the blades flapwise moment of the wind turbine with stall-regulated blades in uniform winds. However, in turbulent winds, the flapwise moment increases to a certain extent as compared to pitch-to-feather control. Moreover, pitch-to-stall control considerably reduces the summed blade pitch movement, despite that it increases the risk of surface damage in the rolling bearings due to oscillating movements with a small amplitude.

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Liu, Liqun, Chunxia Liu und Xuyang Zheng. „Modeling, Simulation, Hardware Implementation of a Novel Variable Pitch Control for H-Type Vertical Axis Wind Turbine“. Journal of Electrical Engineering 66, Nr. 5 (01.09.2015): 264–69. http://dx.doi.org/10.2478/jee-2015-0043.

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Abstract It is well known that the fixed pitch vertical axis wind turbine (FP-VAWT) has some disadvantages such as the low start-up torque and inefficient output efficiency. In this paper, the variable pitch vertical axis wind turbine (VP-VAWT) is analyzed to improve the output characteristics of FP-VAWT by discussing the force of the six blade H type vertical axis wind turbine (VAWT) under the stationary and rotating conditions using built the H-type VAWT model. First, the force of single blade at variable pitch and fixed pitch is analyzed, respectively. Then, the resultant force of six blades at different pitch is gained. Finally, a variable pitch control method based on a six blade H type VP-VAWT is proposed, moreover, the technical analysis and simulation results validate that the variable pitch method can improve the start-up torque of VAWT, and increase the utilization efficiency of wind energy, and reduce the blade oscillation, as comparable with that of FP-VAWT.

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Stol, Karl A., Wenxin Zhao und Alan D. Wright. „Individual Blade Pitch Control for the Controls Advanced Research Turbine (CART)“. Journal of Solar Energy Engineering 128, Nr. 4 (26.07.2006): 498–505. http://dx.doi.org/10.1115/1.2349542.

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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.

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Paraschivoiu, I., O. Trifu und F. Saeed. „H-Darrieus Wind Turbine with Blade Pitch Control“. International Journal of Rotating Machinery 2009 (2009): 1–7. http://dx.doi.org/10.1155/2009/505343.

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A procedure for computing the optimal variation of the blades' pitch angle of an H-Darrieus wind turbine that maximizes its torque at given operational conditions is proposed and presented along with the results obtained on a 7 kW prototype. The CARDAAV code, based on the “Double-Multiple Streamtube” model developed by the first author, is used to determine the performances of the straight-bladed vertical axis wind turbine. This was coupled with a genetic algorithm optimizer. The azimuthal variation of the blades' pitch angle is modeled with an analytical function whose coefficients are used as variables in the optimization process. Two types of variations were considered for the pitch angle: a simple sinusoidal one and one which is more general, relating closely the blades' pitch to the local flow conditions along their circular path. A gain of almost 30% in the annual energy production was obtained with the polynomial optimal pitch control.

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Navalkar, S. T., J. W. van Wingerden und G. A. M. van Kuik. „Individual blade pitch for yaw control“. Journal of Physics: Conference Series 524 (16.06.2014): 012057. http://dx.doi.org/10.1088/1742-6596/524/1/012057.

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7

Kong, Yi Gang, Hao Gu, Jie Wang und Zhi Xin Wang. „Hydraulic Variable Pitch Control and Aerodynamic Load Analysis for Wind Turbine Blades“. Advanced Materials Research 201-203 (Februar 2011): 590–93. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.590.

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This paper reviews the principle of power production, and analyses the influnece on aerodynamic load and output power due to the variation of pitch angle. For three-bladed upwind horizontal axis wind turbine, the blade pitch control is used primarily to adjust the power coefficient and obtain the optimal power at high wind speed, but it also make aerodynamic load, such as edgewise, flapwise and torsion moment, change during variable pitch control. Hydraulic mechanism is used in a process requiring large driving forces and torques, fast response and high stiffness. Therefore, the variable pitch mechanism is operated using electro-hydraulic proportional technology in this paper. Simulation results are presented and analysed to show that aerodynamic load and output power are sensitivity to pitch angle for wind turbine blade. These works lay foundation for the further studying of individual pitch, power control, fatigue and dynamical stability for wind turbine.

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Stanisławski, Jarosław. „Simulation of Boundary States of Helicopter Flight“. Journal of KONES 26, Nr. 2 (01.06.2019): 137–44. http://dx.doi.org/10.2478/kones-2019-0042.

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Abstract Results of simulation of main rotor blade loads and deformations, which can be generated during boundary states of helicopter flight, are presented. Concerned cases of flight envelope include hover at maximum height, level flight at high velocity, pull-up manoeuvres applying cyclic pitch and mixed collective and cyclic control. The simulation calculations were executed for data of light helicopter with three-bladed articulated rotor. For analysis, the real blades are treated as elastic axes with distributed masses of blade segments. The model of deformable blade allows for out-of-plane bending, in plane bending, and torsion. For assumed flight state of helicopter, the equations of rotor blades motion are solved applying Runge-Kutta method. According to Galerkin method, for each concerned azimuthal position of blade the parameters of its motions are assumed as a combination of considered bending and torsion eigen modes of the blade. The loads of rotor blades generated during flight depend due to velocity of flight, helicopter mass, position of rotor axis in air and deflections of swashplate that correspond to collective and cyclic pitch angle applied to rotor blades. The results of simulations presenting rotor loads and blade deformations are shown in form of time-runs and as plots of rotor-disk distributions. The simulations of helicopter flight states may be useful for prediction the conditions of flight-tests without exceeding safety boundaries or may help to define limitations for manoeuvre and control of helicopter.

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Liang, Ying-bin, Li-xun Zhang, Er-xiao Li und Feng-yue Zhang. „Blade pitch control of straight-bladed vertical axis wind turbine“. Journal of Central South University 23, Nr. 5 (Mai 2016): 1106–14. http://dx.doi.org/10.1007/s11771-016-0360-0.

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10

McNerney, G. „Unintended Stalling of the USW 56-100 During Optimum Pitch Control Operation“. Journal of Solar Energy Engineering 116, Nr. 3 (01.08.1994): 153–57. http://dx.doi.org/10.1115/1.2930075.

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The U.S. Windpower 56-100 is a three-bladed, free yaw wind turbine, using full span blade pitch control for power regulation. It is theoretically possible to increase the energy capture of the 56-100 by adjusting the blade angle to the optimum pitch angle on a continuing basis at below rated speeds. This concept was field tested on the 56-100, but it was found that the optimum pitch control logic opens a pathway for the 56-100 to fall into stall operation when the winds are above the rated wind speed. The 56-100 then operates as a stall-regulated wind turbine with an overall reduction of energy capture and an increase in system loads.

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Chougule, P. D., S. R. K. Nielsen und Biswajit Basu. „Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design“. Key Engineering Materials 569-570 (Juli 2013): 668–75. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.668.

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As Development of smallvertical axis wind turbines (VAWT) for urban use is becoming an interestingtopic both within industry and academia. However, there are few new designs ofvertical axis turbines which are customized for building integration. These aregetting importance because they operate at low rotational speed producing veryless noise during operation, although these are less efficient than HorizontalAxis Wind Turbines (HAWT). The efficiency of a VAWT has been significantlyimproved by H-Darrieus VAWT design based on double airfoil technology asdemonstrated by the authors in a previous publication. Further, it is well knowthat the variation of the blade pitch angle during the rotation improves thepower efficiency. A blade pitch variation is implemented by active blade pitchcontrol, which operates as per wind speed and position of the blade withrespect to the rotor. A double multiple stream tube method is used to determinethe performance of the H-Darrieus VAWT. The power coefficient is compared withthat of a fixed pitch and a variable pitch double airfoil blade VAWT. It isdemonstrated that an improvement in power coefficient by 20% is achieved andthe turbine could start at low wind speed

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Cheng, J. C., S. J. Su und J. J. Miau. „Application of Variable Blade Pitch Control on Improving the Performance of Vertical Axis Wind Turbine“. Applied Mechanics and Materials 229-231 (November 2012): 2339–42. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.2339.

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A three blades vertical axis wind turbine simulation is performed to study the unsteady aerodynamic characteristics with blade pitch control. Several fixed and variable blade pitch models under different tip speed ratio are adopted to improve performance of the wind turbine. Results show that an appropriate pitch control model can effectively decrease the range of negative torque regime to reduce the vibration of the wind turbine. Besides, the average torque coefficient as well as the energy capture efficiency can be also improved, especially for the lower tip speed ratio. The overall efficiency of the wind turbines in power generation will be enhanced. For the cases under the tip speed ratio between 1 and 3, the efficiency can be enhanced 243% and 486% for fixed and variable pitch control models respectively as comparing with non-pitch control cases.

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Stol, Karl A. „Disturbance Tracking Control and Blade Load Mitigation for Variable-Speed Wind Turbines“. Journal of Solar Energy Engineering 125, Nr. 4 (01.11.2003): 396–401. http://dx.doi.org/10.1115/1.1628678.

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A composite linear state-space controller was developed for a multi-objective problem in the variable-speed operation of wind turbines. Disturbance Tracking Control theory was applied to the design of a torque controller to optimize energy capture under the influence of persistent wind disturbances. A limitation in the theory for common multi-state models is described; this led to the design of a complementary pitch controller. The goal of the independent blade pitch design was to minimize blade root fatigue loads. A SymDyn model of a two-bladed, 600-kW machine was used for the simulation studies. Results indicate a 24% reduction in blade fatigue damage using the proposed controllers, compared to a conventional torque-only design. However, energy capture was not improved as much as expected, partly due to nonlinearity effects degrading the performance of the state-space estimator design. Tower base fatigue damage was shown to decrease significantly using active pitch.

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14

Bossanyi, E. A. „Individual Blade Pitch Control for Load Reduction“. Wind Energy 6, Nr. 2 (2003): 119–28. http://dx.doi.org/10.1002/we.76.

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Fitzgerald, Breiffni, Andrea Staino und Biswajit Basu. „Wavelet-based individual blade pitch control for vibration control of wind turbine blades“. Structural Control and Health Monitoring 26, Nr. 1 (19.10.2018): e2284. http://dx.doi.org/10.1002/stc.2284.

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16

Chen, Jin, Zhen Hua Wang, Jin Zhou, Hai Hui Song, Zhi Hua Hu und Yang Li. „Wind Turbine Generator Pitch Simulator’s Design“. Advanced Materials Research 443-444 (Januar 2012): 709–12. http://dx.doi.org/10.4028/www.scientific.net/amr.443-444.709.

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Based on the experiment platform consisted of DSPACE simulation system and wind power generator, it is introduced in this paper that Pan-Boolean algebra theory is applied to the wind turbine generator blade pitch simulator’s design. A new Pan-Boolean algebra control algorithm of wind turbine pitch simulator is described in this paper for the fist time. The simulation results show that the wind turbine blade pitch simulator can simulate a real wind power blade pitch adjustment process. This blade pitch simulator can be applied for various types of wind power system with blade pitch system. It is important for researches and applications on wind power.

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Wright, Alan D., und Mark J. Balas. „Design of Controls to Attenuate Loads in the Controls Advanced Research Turbine“. Journal of Solar Energy Engineering 126, Nr. 4 (01.11.2004): 1083–91. http://dx.doi.org/10.1115/1.1792654.

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The wind industry seeks to design wind turbines to maximize energy production and increase fatigue life. To achieve this goal, we must design wind turbines to extract maximum energy and reduce component and system loads. This paper applies modern state-space control design methods to a two-bladed teetering-hub upwind machine located at the National Wind Technology Center. The design objective is to regulate turbine speed in region 3 (above rated wind speed) and enhance damping in several low-damped flexible modes of the turbine. The controls approach is based on the Disturbance Accommodating Control method and provides accountability for wind-speed disturbances. First, controls are designed with the single control input rotor collective pitch to stabilize the first drive-train torsion as well as the tower first fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances first drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections caused by wind shear.

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Liu, Haoming, Suxiang Yang, Wei Tian, Min Zhao, Xiaoling Yuan und Bofeng Xu. „Vibration Reduction Strategy for Offshore Wind Turbines“. Applied Sciences 10, Nr. 17 (02.09.2020): 6091. http://dx.doi.org/10.3390/app10176091.

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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.

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Catana, Razvan Marius, und Grigore Cican. „Global Study of the Performance of a Propeller with a Variable Pitch and a Variable Diameter“. Applied Mechanics and Materials 841 (Juni 2016): 298–302. http://dx.doi.org/10.4028/www.scientific.net/amm.841.298.

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The paperwork presents a study to determine the performance parameters of a propeller characterized by the variable diameter in combination with the variable pitch, a technical method of improving the efficiency of the propeller for different power modes. This solution allows varying the load of the propeller by varying the propeller blade diameter in connection with the changing pitch blade at a constant speed mode setting. The solution allows varying the propeller area to control the air flow and to obtain the optimum load at different stage blade angles varying the pitch into the optimum position at a constant speed mode to realize the increase of the air flow through the propeller blades at different power modes. The study is performed only in aerodynamic mode and not in the technical constructive mode.

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Wang, Chen, De Zhou Meng und Xu Fang Bo. „The Research about the Wind Turbines Pitch Control“. Advanced Materials Research 773 (September 2013): 87–90. http://dx.doi.org/10.4028/www.scientific.net/amr.773.87.

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Based on the background of wind power, considering the wind blade sweep area on the uneven distribution, this paper is using the PID control algorithm to control the pitch system. At the same time, this paper is using Siemens SCL to programming, simulating on the experimental platform. Simulation results show the validity of the theory and the feasibility of the system, realizing variable pitch control of fan blade.

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Kjellin, Jon, Sandra Eriksson und Hans Bernhoff. „Electric Control Substituting Pitch Control for Large Wind Turbines“. Journal of Wind Energy 2013 (18.09.2013): 1–4. http://dx.doi.org/10.1155/2013/342061.

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A completely electrical control of a variable speed wind turbine is experimentally verified. A vertical axis wind turbine with a direct driven generator and an electrical system with diode rectification and full inverter connected to the electric grid is presented. This is the first paper that presents this novel 200 kW wind power plant erected at the west coast of Sweden. The turbine has fixed pitch and is only controlled electrically accommodated by passive stall of the blades. By electrically controlling the generator rotational speed with the inverter, passive stall regulation is enabled. The first results on experimental verification of stall regulation in gusty wind speeds are presented. The experiments show that the control system can keep the turbine rotational speed constant even at very gusty winds. It is concluded that electrical control accommodated by passive stall is sufficient as control of the wind turbine even at high wind speeds and can substitute mechanical control such as blade pitch.

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Dai, J.-C., Y.-P. Hu, D.-S. Liu und X. Long. „Modelling and characteristics analysis of the pitch system of large scale wind turbines“. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 225, Nr. 3 (19.07.2010): 558–67. http://dx.doi.org/10.1243/09544062jmes2257.

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The individual pitch drive system of large-scale wind turbines was analysed in this article. In this pitch system, the induction motor, three-stage planetary gearbox, and motor vector control were adopted. In order to investigate the system dynamic behaviour, its non-linear dynamical model was established, mainly including three parts: induction motor model in d— q frame, dynamic model of three-stage planetary gears, and transmission shaft model. The dynamic responses of gearbox—blade subsystem and motor—gearbox—blade system were analysed in detail, respectively. Then, the pitch system control model was established in which rotor flux field-oriented vector control and double close-loop servo control with speed and position feedback were employed. In simulation, the algorithm TR-BDF2 was adopted to solve the dynamic equations. The research results show that the deviation between the pitch angle and its command value is very small in steady state, pitch speed and acceleration fluctuations appear when impact effect is produced due to gear backlash, and the different blade may have different variable pitch speed and acceleration in some pitch region. The research results give a reasonable explanation for running mechanism of the individual pitch system and are helpful for optimization design and control for the individual blade pitch control system used in large-scale wind turbines.

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Horb, S., R. Fuchs, A. Immas, F. Silvert und P. Deglaire. „Variable pitch control for vertical-axis wind turbines“. Wind Engineering 42, Nr. 2 (20.03.2018): 128–35. http://dx.doi.org/10.1177/0309524x18756972.

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NENUPHAR aims at developing the next generation of large-scale floating offshore vertical-axis wind turbine. To challenge the horizontal-axis wind turbine, the variable blade pitch control appears to be a promising solution. This article focuses on blade pitch law optimization and resulting power and thrust gain depending on the operational conditions. The aerodynamics resulting from the implementation of a variable blade pitch control are studied through numerical simulations, either with a three-dimensional vortex code or with two-dimensional Navier-stokes simulations (two-dimensional computational fluid dynamics). Results showed that the three-dimensional vortex code used as quasi-two-dimensional succeeded to give aerodynamic loads in very good agreement with two-dimensional computational fluid dynamics simulation results. The three-dimensional-vortex code was then used in three-dimensional configuration, highlighting that the variable pitch can enhance the vertical-axis wind turbine power coefficient ( Cp) by more than 15% in maximum power point tracking mode and decrease it by more than 75% in power limitation mode while keeping the thrust below its rated value.

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Gao, Feng. „Aerodynamic Modeling Research of Wind Turbine Suitable for Individual Pitch Control“. Advanced Materials Research 823 (Oktober 2013): 175–79. http://dx.doi.org/10.4028/www.scientific.net/amr.823.175.

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Momentum theory model which was widely used in pitch control cant calculate wind turbine load, so it can't meet pitch control research needs of large-scale wind turbine. In this paper, the traditional model based on momentum theory firstly was improved to be able to calculate load under some hypothesis. Then the wind turbine model suitable for individual pitch control was built based on blade element theory. And wind shear and tower shadow on load of wind turbine was calculated and analyzed. Finally, the model was simulated in the turbulent flow conditions and load was analyzed by Bladed. Simulations indicate that the model built in the paper can be used in simulation and verification of individual pitch control, and the conclusions drawn by load analysis can provide theoretic basis and the reference standard for individual pitch control strategy.

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Cheon, Jongmin, Jinwook Kim, Joohoon Lee, Kichang Lee und Youngkiu Choi. „Development of Hardware-in-the-Loop-Simulation Testbed for Pitch Control System Performance Test“. Energies 12, Nr. 10 (27.05.2019): 2031. http://dx.doi.org/10.3390/en12102031.

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This paper deals with the development of a wind turbine pitch control system and the construction of a Hardware-in-the-Loop-Simulation (HILS) testbed for the performance test of the pitch control system. When the wind speed exceeds the rated wind speed, the wind turbine pitch controller adjusts the blade pitch angles collectively to ensure that the rotor speed maintains the rated rotor speed. The pitch controller with the individual pitch control function can add individual pitch angles into the collective pitch angles to reduce the mechanical load applied to the blade periodically due to wind shear. Large wind turbines often experience mechanical loads caused by wind shear phenomena. To verify the performance of the pitch control system before applying it to an actual wind turbine, the pitch control system is tested on the HILS testbed, which acts like an actual wind turbine system. The testbed for evaluating the developed pitch control system consists of the pitch control system, a real-time unit for simulating the wind and the operations of the wind turbine, an operational computer with a human–machine interface, a load system for simulating the actual wind load applied to each blade, and a real pitch bearing. Through the several tests based on HILS test bed, how well the pitch controller performed the given roles for each area in the entire wind speed area from cut-in to cut-out wind speed can be shown.

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Son, Tae-Ha, und Jun-Young Huh. „P-50 The characteristic analysis of response control for the power plant fan pitch blade control actuator“. Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2007.6 (2007): _P—50–1_—_P—50–6_. http://dx.doi.org/10.1299/jsmeatem.2007.6._p-50-1_.

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27

Srinivasamurthy, Sharath, Kazuhiro Iijima, Masahiko Fujikubo und Yasunori Nihei. „Elastic-plastic behavior analysis for a flexible FOWT subjected to blade pitch control malfunction“. Journal of the Japan Society of Naval Architects and Ocean Engineers 23 (2016): 179–87. http://dx.doi.org/10.2534/jjasnaoe.23.179.

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Kakuya, Hiromu, Takashi Shiraishi, Shigeo Yoshida, Tomoaki Utsunomiya und Iku Sato. „Experimental results of floating platform vibration control with mode change function using full-scale spar-type floating offshore wind turbine“. Wind Engineering 42, Nr. 3 (30.10.2017): 230–42. http://dx.doi.org/10.1177/0309524x17737336.

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Floating offshore wind turbines have great potential for harvesting renewable energy sources since offshore wind is stronger and more stable than onshore wind. The foundations of floating offshore wind turbines are not rigidly fixed and it leads to vibration of the floating platform pitch angle. This vibration is caused by fast blade pitch angle motions of variable speed control for controlling rotor speed at rated values. This study proposes a control method to address this vibration, floating platform vibration control. This method extracts a natural frequency component of the vibration from the floating platform pitch angle signal by a band pass filter and controls the blade pitch angle on the basis of proportional–derivative control. Its key characteristic is changing control modes in accordance with electrical power. Experiments using a full-scale spar-type floating offshore wind turbine were performed, and results show that the proposed floating platform vibration control can suppress the vibration of floating platform pitch angle.

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Iqbal, Atif, Deng Ying, Adeel Saleem, Muhammad Aftab Hayat und Muhammad Adnan Samad. „Modelling and Comparison of Different Control Techniques for 1-MW Wind Turbine to Extract Maximum Power Through Pitch Angle Control“. Journal of Computational and Theoretical Nanoscience 17, Nr. 2 (01.02.2020): 1326–31. http://dx.doi.org/10.1166/jctn.2020.8808.

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Wind energy is the most clean and attractive source in addition to it abundant in nature. The main challenge in extracting the energy through wind is the uneven and unfamiliar turbulent wind field. Wind turbine pitch system plays pivotal role in achieving required blade angle along with it to run generator at its rated speed. This paper focuses blade pitch control to improve power and to keep the system working in stable and safe manner. Blade pitch angle control has an important role in achieving maximum power, so the proposed controller is presented to maximize the power and protect the system in case of uncertain conditions. Proposed controller is compared with conventional controller to investigate in addition to validate the technique as well as working. Different case studies over variable wind speed has been discussed to get the improved power and to achieve safe and normal operation. Simulation is implemented on 1-MW wind turbine through MATLAB/Simulink and achieved the improved results from proposed controller.

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Eggers,, A. J., R. Digumarthi und K. Chaney. „Wind Shear and Turbulence Effects on Rotor Fatigue and Loads Control“. Journal of Solar Energy Engineering 125, Nr. 4 (01.11.2003): 402–9. http://dx.doi.org/10.1115/1.1629752.

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The effects of wind shear and turbulence on rotor fatigue and loads control are explored for a large horizontal axis wind turbine in variable speed operation at wind speeds from 4 to 20 m/s. Two- and three-blade rigid rotors are considered over a range of wind shear exponents up to 1.25 and a range of turbulence intensities up to 17%. RMS blade root flatwise moments are predicted to be very substantially increased at higher wind shear, and resultant fatigue damage is increased by many orders of magnitude. Smaller but similar trends occur with increasing turbulence levels. In-plane fatigue damage is driven by 1P gravity loads and exacerbated by turbulence level at higher wind speeds. This damage is higher by one to two orders of magnitude at the roots of the three-blade rotor compared with the two-blade rotor. Individual blade pitch control of fluctuating flatwise moments markedly reduces flatwise fatigue damage due to this source, and, to a lesser degree, the in-plane damage due to turbulence. The same is true of fluctuating rotor torque moments driven by turbulence and transmitted to the drive train. Blade root moments out of the plane of rotation aggregate to create rotor pitching and yawing moments transmitted to the turbine structure through the drive train to the yaw drive system and the tower. These moments are predicted to be relatively insensitive to turbulence level and essentially proportional to the wind shear exponent for the two-blade rotor. Fluctuating moments are substantially reduced with individual blade pitch control, and addition of a teeter degree-of-freedom should further contribute to this end. Fluctuating pitching and yawing moments of the three-blade rotor are substantially less sensitive to wind shear, more sensitive to turbulence level, and substantially lower than those for the two-blade rotor. Mean rotor torque and, hence, power are essentially the same for both rotors, independent of wind shear, and are somewhat reduced with individual blade pitch control of fluctuating flatwise moments. The same is true of mean rotor thrust; however fluctuations in rotor thrust are substantially reduced with individual blade pitch control.

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31

Liebst, B. S. „A Pitch Control System for the KaMeWa Wind Turbine“. Journal of Dynamic Systems, Measurement, and Control 107, Nr. 1 (01.03.1985): 47–52. http://dx.doi.org/10.1115/1.3140706.

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This study is the design of a pitching blade control system for the National Swedish Board for Energy Source Development KaMeWa wind turbine. Full state controllers are designed utilizing optimal control theory to reduce blade and tower vibration, power oscillations, and improve gust response. The results show that substantial vibration reduction can be obtained with the existing pitch actuators installed presently on the machine.

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Agarwala, Ranjeet, und Paul I. Ro. „Separated Pitch Control at Tip: Innovative Blade Design Explorations for Large MW Wind Turbine Blades“. Journal of Wind Energy 2015 (24.02.2015): 1–12. http://dx.doi.org/10.1155/2015/895974.

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This paper focuses on the deployment and evaluation of a separated pitch control at blade tip (SePCaT) control strategy for large megawatt (MW) wind turbine blade and explorations of innovative blade designs as a result of such deployment. SePCaT configurations varied from five to thirty percent of the blade length in 5 percentage increments (SePCaT5, SePCaT10, SePCaT15, SePCaT20, SePCaT25, and SePCaT30) are evaluated by comparing them to aerodynamical responses of the traditional blade. For low, moderate, high, and extreme wind speed variations treated as 10, 20, 30, and 40 percent of reference wind speeds, rotor power abatement in region 3 of the wind speed power curve is realized by feathering full length blade by 6, 9, 12, and 14 degrees, respectively. Feathering SePCaT30, SePCaT25, SePCaT20, and SePCaT15 by 14, 16, 26, and 30 degrees, respectively, achieves the same power abatement results when compared to traditional blade at low wind speeds. Feathering SePCaT30, SePCaT25, and SePCaT20 by 18, 26, and 30 degrees on the other hand has the same effect at high wind speeds. SePCaT30 feathered to 26 and 30 degrees has the same abatement effects when compared to traditional blade at high and extreme wind speeds.

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33

Guo, Jia, Timing Qu und Liping Lei. „Effect of Pitch Parameters on Aerodynamic Forces of a Straight-Bladed Vertical Axis Wind Turbine with Inclined Pitch Axes“. Applied Sciences 11, Nr. 3 (24.01.2021): 1033. http://dx.doi.org/10.3390/app11031033.

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Pitch regulation plays a significant role in improving power performance and achieving output control in wind turbines. The present study focuses on a novel, pitch-regulated vertical axis wind turbine (VAWT) with inclined pitch axes. The effect of two pitch parameters (the fold angle and the incline angle) on the instantaneous aerodynamic forces and overall performance of a straight-bladed VAWT under a tip-speed ratio of 4 is investigated using an actuator line model, achieved in ANSYS Fluent software and validated by previous experimental results. The results demonstrate that the fold angle has an apparent influence on the angles of attack and forces of the blades, as well as the power output of the wind turbine. It is helpful to further study the dynamic pitch regulation and adaptable passive pitch regulation of VAWTs. Incline angles away from 90° lead to the asymmetric distribution of aerodynamic forces along the blade span, which results in an expected reduction of loads on the main shaft and the tower of VAWTs.

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34

Malovrh, Brendon, und Farhan Gandhi. „Localized Individual Blade Root Pitch Control for Helicopter Blade—Vortex Interaction Noise Reduction“. Journal of the American Helicopter Society 55, Nr. 3 (01.07.2010): 32007–3200712. http://dx.doi.org/10.4050/jahs.55.032007.

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35

Zhang, Dahai, Philip Cross, Xiandong Ma und Wei Li. „Improved control of individual blade pitch for wind turbines“. Sensors and Actuators A: Physical 198 (August 2013): 8–14. http://dx.doi.org/10.1016/j.sna.2013.04.020.

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36

Namik, H., und K. Stol. „Individual blade pitch control of floating offshore wind turbines“. Wind Energy 13, Nr. 1 (Januar 2010): 74–85. http://dx.doi.org/10.1002/we.332.

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37

Dunne, Fiona, und Lucy Y. Pao. „Optimal blade pitch control with realistic preview wind measurements“. Wind Energy 19, Nr. 12 (01.03.2016): 2153–69. http://dx.doi.org/10.1002/we.1973.

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38

Kennedy, Ciaran R., Sean B. Leen und Conchúr MÓ Brádaigh. „A preliminary design methodology for fatigue life prediction of polymer composites for tidal turbine blades“. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 226, Nr. 3 (18.04.2012): 203–18. http://dx.doi.org/10.1177/1464420712443330.

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Tidal turbine blades experience significant fatigue cycles during operation and it is expected that fatigue strength will be a major consideration in their design. Glass fibre reinforced polymers are a candidate low-cost material for this application. This article presents a methodology for preliminary fatigue design of glass fibre reinforced polymer tidal turbine blades. The methodology combines: (a) a hydrodynamic model for calculation of local distributions of fluid–blade forces; (b) a finite element structural model for prediction of blade strain distributions; (c) a fatigue damage accumulation model, which incorporates mean stress effects; and (d) uniaxial fatigue testing of two candidate glass fibre reinforced polymer materials (for illustrative purposes). The methodology is applied here for the preliminary design of a three-bladed tidal turbine concept, including tower shadow effects, and comparative assessment of pitch- and stall-regulated control with respect to fatigue performance.

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39

Shen, Xin, Xiaocheng Zhu und Zhaohui Du. „Load control and unsteady aerodynamics for floating wind turbines“. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 235, Nr. 6 (09.02.2021): 1501–26. http://dx.doi.org/10.1177/0957650921993255.

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Unlike fixed-base offshore wind turbine, the soft floating platform introduces 6 more degrees of freedom of motions to the floating offshore wind turbine. This may cause much more complex inflow environment to the wind turbine rotors compared with fixed-base wind turbine. The wind seen locally on the blade changes due to the motions of the floating wind turbine platform which has a direct impact on the aerodynamic condition on the blade such as the angle of attack and the inflow velocity. Such unsteady aerodynamic effects may lead to high fluctuation of the loads and power output. The present work aims to study the high unsteady aerodynamic performance of the floating wind turbine under platform surge motion. The unsteady aerodynamic loads are predicted with a lifting surface method with a free wake model. A preview predict control algorithm is used as the pitch control strategy. A full scale U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) 5 MW floating wind turbine is chosen as the subject of the present study. The unsteady aerodynamic performance and instabilities have been discussed in detail under prescribed platform surge motions with different control targets. Both minimizing the power output and rotor thrust fluctuation are set as the control objectives respectively. The theory analysis and the simulation results indicate that the blade pitch control can effectively alleviate the variation of the rotor thrust under platform surge motions. Larger amplitude of the variation of blade pitch is needed to alleviate the variation of the wind turbine power and this leads to high rotor thrust fluctuation. It is also shown that negative damping can be achieved during the blade pitch control process and may lead the floating platform wind turbine system into unstable condition.

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40

Stol, Karl A., und Mark J. Balas. „Periodic Disturbance Accommodating Control for Blade Load Mitigation in Wind Turbines“. Journal of Solar Energy Engineering 125, Nr. 4 (01.11.2003): 379–85. http://dx.doi.org/10.1115/1.1621672.

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Performance of a model-based periodic gain controller for wind turbines is presented using Disturbance Accommodating Control (DAC) techniques to estimate fluctuating wind disturbances. The control objective is to regulate rotor speed at above-rated wind speeds while mitigating cyclic blade root loads. Actuation is via individual blade pitch, and sensors are limited to rotor angle and speed. The modeled turbine is a two-bladed, downwind machine with simple blade and tower flexibility having four degrees of freedom. Comparisons are made to a time-invariant DAC controller and to a proportional-integral-derivative (PID) design. Simulations are performed using a fluctuating wind input and a nonlinear turbine model. Results indicate that the state-space control designs are effective in reducing blade loads without a sacrifice in speed regulation. The periodic controller shows the most potential because it uses a time-varying turbine model to estimate unmeasured states. The use of additional sensors to help reconstruct the blade flap rate can significantly improve the level of load attenuation, as witnessed in full-state feedback results.

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41

Genov, Julian. „A synthesis of a blade pitch control for large wind turbines, taking into account the functional dependence of the torque generated in the blades from the azimuth angle“. MATEC Web of Conferences 234 (2018): 04007. http://dx.doi.org/10.1051/matecconf/201823404007.

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In multi-MW (1MW and up) wind generation systems a variable speed - variable pitch (VS-VP) control technology is usually adopted to improve speed and torque characteristics and to obtain the optimal energy, which means to obtain the maximum power at low wind speed and the rated power at high wind speed. The power generated by an individual blade of the wind turbine changes considerably during rotation due for the change of wind speed in vertical direction, which decreases the angles of attack in the low blade positions and which leads to a reducing the generated energy. In the paper basing on BEM theory modification for none-homogenously fluid field and an optimization procedure is obtained an individual variable pitch control law as function of wind speed values and blades positions.

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42

Kakuya, Hiromu, Shigeo Yoshida, Iku Sato und Tomoaki Utsunomiya. „A study on the platform-pitching vibration of floating offshore wind turbines based on classical control theory“. Wind Engineering 44, Nr. 6 (16.07.2019): 610–30. http://dx.doi.org/10.1177/0309524x19862761.

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One of the issues of floating offshore wind turbines is the platform-pitching vibration generated by the blade pitch angle motion of the variable speed control. This study investigated the platform-pitching vibration based on the classical control theory using a transfer function between the generator speed and the nacelle pitch angle. This study also investigated the impact of the floating platform vibration control, which can suppress the vibration by adjusting the blade pitch angle according to the nacelle pitch angle, by using a transfer function to which floating platform vibration control is added. The stabilities of these transfer functions were determined using the Nyquist stability criterion, and the impact of the floating platform vibration control parameters was investigated using Bode diagrams.

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43

Gennaretti, Massimo, Giovanni Bernardini, Jacopo Serafini und Marco Molica Colella. „Helicopter Vibratory Loads Alleviation through Combined Action of Trailing-Edge Flap and Variable-Stiffness Devices“. International Journal of Aerospace Engineering 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/485964.

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The aim of this paper is the assessment of the capability of controllers based on the combined actuation of flaps and variable-stiffness devices to alleviate helicopter main rotor vibratory hub loads. Trailing-edge flaps are positioned at the rotor blade tip region, whereas variable-stiffness devices are located at the pitch link and at the blade root. Control laws are derived by an optimal control procedure based on the best trade-off between control effectiveness and control effort, under the constraint of satisfaction of the equations governing rotor blade aeroelastic response. The numerical investigation concerns the analysis of performance and robustness of the control techniques developed, through application to a four-bladed helicopter rotor in level flight. The identification of the most efficient control configuration is also attempted.

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44

Liu, Tingrui. „System modeling and instability control of wind turbine blade based on hydraulic pitch system and radial basic function neural network proportional–integral–derivative controller“. Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 232, Nr. 10 (02.07.2018): 1412–28. http://dx.doi.org/10.1177/0959651818784435.

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System modeling and aeroservoelastic control for divergent instability of stall-induced composite wind turbine blade modeled as thin-walled symmetric layup beam analysis have been investigated based on hydraulic pitch system and radial basic function neural network control. The blade is modeled as single-cell thin-walled beam structure with the circumferentially asymmetric stiffness design, exhibiting flap/lead-lag bending coupling deformation. The stall flutter and aeroservoelastic control of composite blade are investigated based on dynamic stall Beddoes–Leishman aerodynamic model and radial basic function neural network proportional–integral–derivative controller, with pitch actuator performed by hydraulic system. The system motion equations consist of the aeroelastic equations and the six-order pitch equation. The nonlinear aeroelastic responses, including both flap/lead-lag responses and pitch angle responses under different parameters, are solved by Galerkin method and the nonlinear time integration scheme with nonlinear residual analysis. To verify the effectiveness of the control scheme and realize visualized display of large thin-walled blade in the laboratory, experimental platform based on hardware-in-the-loop simulation is built to realize real-time control and virtual simulation. The platform structure consists of PLC hardware, monitoring interface in configuration software, and simulation environment that is connected by the OPC server with PLC system. The platform lays the foundation for vibrational behavior research on visualization of large wind turbine blade under divergent stall situation and verifies the real-time feasibility of the control algorithm proposed.

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Zalkind, Daniel S., Gavin K. Ananda, Mayank Chetan, Dana P. Martin, Christopher J. Bay, Kathryn E. Johnson, Eric Loth, D. Todd Griffith, Michael S. Selig und Lucy Y. Pao. „System-level design studies for large rotors“. Wind Energy Science 4, Nr. 4 (11.11.2019): 595–618. http://dx.doi.org/10.5194/wes-4-595-2019.

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Abstract. We examine the effect of rotor design choices on the power capture and structural loading of each major wind turbine component. A harmonic model for structural loading is derived from simulations using the National Renewable Energy Laboratory (NREL) aeroelastic code FAST to reduce computational expense while evaluating design trade-offs for rotors with radii greater than 100 m. Design studies are performed, which focus on blade aerodynamic and structural parameters as well as different hub configurations and nacelle placements atop the tower. The effects of tower design and closed-loop control are also analyzed. Design loads are calculated according to the IEC design standards and used to create a mapping from the harmonic model of the loads and quantify the uncertainty of the transformation. Our design studies highlight both industry trends and innovative designs: we progress from a conventional, upwind, three-bladed rotor to a rotor with longer, more slender blades that is downwind and two-bladed. For a 13 MW design, we show that increasing the blade length by 25 m, while decreasing the induction factor of the rotor, increases annual energy capture by 11 % while constraining peak blade loads. A downwind, two-bladed rotor design is analyzed, with a focus on its ability to reduce peak blade loads by 10 % per 5∘ of cone angle and also reduce total blade mass. However, when compared to conventional, three-bladed, upwind designs, the peak main-bearing load of the upscaled, downwind, two-bladed rotor is increased by 280 %. Optimized teeter configurations and individual pitch control can reduce non-rotating damage equivalent loads by 45 % and 22 %, respectively, compared with fixed-hub designs.

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46

Paulos, James, und Mark Yim. „Cyclic Blade Pitch Control Without a Swashplate for Small Helicopters“. Journal of Guidance, Control, and Dynamics 41, Nr. 3 (März 2018): 689–700. http://dx.doi.org/10.2514/1.g002683.

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47

Laks, Jason, Lucy Pao, Alan Wright, Neil Kelley und Bonnie Jonkman. „The use of preview wind measurements for blade pitch control“. Mechatronics 21, Nr. 4 (Juni 2011): 668–81. http://dx.doi.org/10.1016/j.mechatronics.2011.02.003.

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48

Saxena, Anand, und Inderjit Chopra. „Wind Tunnel Testing of a Swashplateless Rotor with Compact Brushless Motor Actuated Flaps for Primary Control“. Journal of the American Helicopter Society 65, Nr. 1 (01.01.2020): 1–6. http://dx.doi.org/10.4050/jahs.65.012010.

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A swashplateless rotor trim using brushless DC motor actuated trailing edge flaps was achieved in the Glenn L. Martin wind tunnel. A 6-ft-diameter, four-bladed articulated rotor with motor–flap system integrated into the NACA 0012 airfoil section was fabricated. A Maxon EC-10 brushless DC motor as an on-blade actuator and a lightweight mechanism were incorporated to actuate the trailing edge flap. The rotor torsion frequency was lowered to 2/rev using soft pitch links, allowing the blade pitch response to a trailing edge flap input. A closed-loop controller was employed to ensure trailing edge flap operation at desired amplitude with correct phase difference and in sync with the rotor azimuth. A trim methodology was implemented, and wind tunnel trim was achieved at 900 and 1200 RPM for a number of advance ratios. Results show that the brushless DC motors can provide sufficient primary control authority and have structural strength to withstand centrifugal loads, while fitting within airfoil profile and incurring minimal weight penalty.

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49

Sekula, Martin K., und Matthew L. Wilbur. „Analysis of a Multiflap Control System for a Swashplateless Rotor“. Journal of the American Helicopter Society 57, Nr. 3 (01.07.2012): 1–12. http://dx.doi.org/10.4050/jahs.57.032006.

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An analytical study was conducted examining the feasibility of a swashplateless rotor controlled through two trailing-edge flaps (TEFs), where the cyclic and collective controls were provided by separate TEFs. This analysis included a parametric study examining the impact of various design parameters on TEF deflections. Blade pitch bearing stiffness; blade pitch index; and flap chord, span, location, and control function of the inboard and outboard flaps were systematically varied on a utility-class rotorcraft trimmed in steady level flight. Gradient-based optimizations minimizing flap deflections were performed to identify single- and two-TEF swashplateless rotor designs. Steady, forward flight analysis suggest that a two-TEF swashplateless rotor where the outboard flap provides cyclic control and inboard flap provides collective control can reduce TEF deflection requirements without a significant impact on power, compared to a single-TEF swashplateless rotor design.

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Fankai, Kong, Wang Liying und Zhang Di. „Optimization on the Law of Variable-Pitch Vertical-Axis Tidal Current Turbine“. MATEC Web of Conferences 153 (2018): 03002. http://dx.doi.org/10.1051/matecconf/201815303002.

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In order to improve the hydrodynamic performance of the vertical-axis variable-pitch current turbine, with analyzing on the existing design mentality of blade control mechanism, an optimized law of variable-pitch vertical-axis tidal current turbine was given in terms of the instantaneous moment coefficient of the blade. A method for solving the lift - drag coefficient of Blade by wind - hole test data is given. The optimized kinematic model has a significant reference value for the further development of vertical axis turbine model test.

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