scholarly journals Adaptive fuzzy Proportion Integration Differentiation control in hydraulic offshore wind turbine for optimal power extraction based on the estimated wind speed

2020 ◽  
Vol 8 (5) ◽  
pp. 1604-1619 ◽  
Author(s):  
YaJun Fan ◽  
AnLe Mu
2015 ◽  
Vol 137 (5) ◽  
Author(s):  
A. AlSam ◽  
R. Szasz ◽  
J. Revstedt

The impacts of swells on the atmospheric boundary layer (ABL) flows and by this on the standalone offshore wind turbine (WT) performance are investigated by using large eddy simulations (LES) and actuator-line techniques. At high swell to wind speed ratio, the swell-induced stress reduces the total wind stress resulting in higher wind velocity, less wind shear, and lower turbulence intensity level. These effects increase by increasing swell to wind speed ratio (C/U) and/or swell steepness. Moreover, for the same hub-height wind speed (Uhub), the presence of swells increases the turbine power extraction rate by about 3% and 8.4% for C/Uhub = 1.53 and 2.17, respectively.


2011 ◽  
Vol 52-54 ◽  
pp. 1556-1559
Author(s):  
Ping He ◽  
Nai Chao Chen ◽  
Dan Mei Hu

The liquid-gas flow is proposed to accurately simulate the offshore environmental state. The aerodynamic feature is estimated using the three-dimensional model of horizontal-axis wind turbine with NRELS809 series aerofoil by means of the simulating software tool of FLUENT. The variable speed is implemented via the six different wind speeds. The calculated results show that the similarly evolutional tendency of velocity occurs in the wake region when operating at the six variable speeds. The stall speed is related to blade height and wind speed. The small blade height or large wind speed also leads to the serious stall phenomenon. The total force is conducted to estimate the potential capability for leeward and windward surface to capture wind power. The calculated results reveal that the larger wind speed facilitates generating the more magnitude of total force. However, the velocity and force feature for the wind turbine has the especially rapid change at the wind speed of 6 m/s, which perhaps results from the intrinsic geometry and configuration.


Author(s):  
Jiajia Yang ◽  
Erming He ◽  
Juncheng Shu

Floating offshore wind turbine is a complex rigid-flexible coupling nonlinear system, and the accurate dynamic model is difficultly established. Therefore, the wind-wave interference cannot be improved by adopting the conventional control strategy. In order to solve this problem, an adaptive fuzzy controller (AFC) is used to suppress the dynamic response of floating wind turbine. Two correction factors are introduced to optimize the fuzzy rule, and the traditional fuzzy controller (FC) is firstly obtained. Since the balance positions change and structural parameter perturbation of the wind turbine, an AFC is designed and validated. Finally, the suppression vibration responses ability of floating offshore wind turbine by using the different control strategies is studied under the random wind-wave disturbance and blade pitch control system coupling effect. The simulation results show that the tracking ability of the AFC to the target value is obviously higher than that of the FC; Comparing with the passive control strategy, the suppression vibration effect on the power spectral density (PSD) of the platform pitch (PFPI) motion peak can increase by 39.06% by adopting the AFC.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Wojciech Popko ◽  
Amy Robertson ◽  
Jason Jonkman ◽  
Fabian Wendt ◽  
Philipp Thomas ◽  
...  

Abstract The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project validates OWT models against the measurements recorded on a Senvion 5M wind turbine supported by the OWEC Quattropod from the alpha ventus offshore wind farm. The following operating conditions of the wind turbine were chosen for the validation: (1) idling below the cut-in wind speed, (2) rotor-nacelle assembly (RNA) rotation maneuver below the cut-in wind speed, (3) power production below and above the rated wind speed, and (4) shutdown. A number of validation load cases were defined based on these operating conditions. The following measurements were used for validation: (1) strains and accelerations recorded on the support structure and (2) pitch, yaw, and azimuth angles, generator speed, and electrical power recorded from the RNA. Strains were not directly available from the majority of the OWT simulation tools; therefore, strains were calculated based on out-of-plane bending moments, axial forces, and cross-sectional properties of the structural members. The simulation results and measurements were compared in terms of time series, discrete Fourier transforms, power spectral densities, and probability density functions of strains and accelerometers. A good match was achieved between the measurements and models setup by OC5 Phase III participants.


2006 ◽  
Vol 23 (7) ◽  
pp. 888-901 ◽  
Author(s):  
R. J. Barthelmie ◽  
G. C. Larsen ◽  
S. T. Frandsen ◽  
L. Folkerts ◽  
K. Rados ◽  
...  

Abstract This paper gives an evaluation of most of the commonly used models for predicting wind speed decrease (wake) downstream of a wind turbine. The evaluation is based on six experiments where free-stream and wake wind speed profiles were measured using a ship-mounted sodar at a small offshore wind farm. The experiments were conducted at varying distances between 1.7 and 7.4 rotor diameters downstream of the wind turbine. Evaluation of the models compares the predicted and observed velocity deficits at hub height. A new method of evaluation based on determining the cumulative momentum deficit over the profiles is described. Despite the apparent simplicity of the experiments, the models give a wide range of predictions. Overall, it is not possible to establish any of the models as having individually superior performance with respect to the measurements.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3702
Author(s):  
Wen-Ko Hsu ◽  
Chung-Kee Yeh

In this study, we present the wind distributions from a long-term offshore met mast and a novel approach based on the measure–correlate–predict (MCP) method from short-term onshore-wind-turbine data. The annual energy production (AEP) and capacity factors (CFs) of one onshore and four offshore wind-turbine generators (WTG) available on the market are evaluated on the basis of wind-distribution analysis from both the real met mast and the MCP method. Here, we also consider the power loss from a 4-month light detection and ranging (LiDAR) power-curve test on an onshore turbine to enhance the accuracy of further AEP and CF evaluations. The achieved Weibull distributions could efficiently represent the probability distribution of wind-speed variation, mean wind speed (MWS), and both the scale and shape parameters of Weibull distribution in Taiwan sites. The power-loss effect is also considered when calculating the AEPs and CFs of different WTGs. Successful offshore wind development requires (1) quick, accurate, and economical harnessing of a wind resource and (2) selection of the most suitable and efficient turbine for a specific offshore site.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4670
Author(s):  
Emir Omerdic ◽  
Jakub Osmic ◽  
Cathal O’Donnell ◽  
Edin Omerdic

A control algorithm for Parallel Connected Offshore Wind Turbines with permanent magnet synchronous Generators (PCOWTG) is presented in this paper. The algorithm estimates the optimal collective speed of turbines based on the estimated mechanical power of wind turbines without direct measurement of wind speed. In the proposed topology of the wind farm, direct-drive Wind Turbine Generators (WTG) is connected to variable low-frequency AC Collection Grids (ACCG) without the use of individual power converters. The ACCG is connected to a variable low-frequency offshore AC transmission grid using a step-up transformer. In order to achieve optimum wind power extraction, the collective speed of the WTGs is controlled by a single onshore Back to Back converter (B2B). The voltage control system of the B2B converter adjusts voltage by keeping a constant Volt/Hz ratio, ensuring constant magnetic flux of electromagnetic devices regardless of changing system frequency. With the use of PI pitch compensators, wind power extraction for each wind turbine is limited within rated WTG power limits. Lack of load damping in offshore wind parks can result in oscillatory instability of PCOWTG. In this paper, damping torque is increased using P pitch controllers at each WTG that work in parallel with PI pitch compensators.


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