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Numerical analysis and experimental investigation of wind turbine blades with innovative features:Structural response and characteristics

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Science China(Technological Sciences) 2015年第1期58卷 1-8页

作者： CHEN Xiao QIN ZhiWen YANG Ke ZHAO XiaoLu XU JianZhong National Laboratory of wind Turbine Blade Research & Development Center Institute of Engineering ThermophysicsChinese Academy of Sciences

Innovative features of wind turbine blades with flatback at inboard region,thick airfoils at inboard as well as mid-span region and transversely stepped thickness in spar caps have been proposed by Institute of Engineering Thermophysics,Chinese Academy of Sciences(IET-wind)in order to improve both aerodynamic and structural efficiency of rotor *** verify the proposed design concepts,this study first presented numerical analysis using finite element method to clarify the effect of flatback on local buckling strength of the inboard *** models with various loading cases,inboard configurations,and core materials were comparatively ***,a prototype blade incorporated with innovative features was manufactured and tested under static bending loads to investigate its structural response and *** was found that rotor blades with flatback exhibited favorable local buckling strength at the inboard region compared with those with conventional sharp trailing edge when low-density PVC foam was *** prototype blade showed linear behavior under extreme loads in spar caps,aft panels,shear web and flatback near the maximum chord which is usually susceptible to buckling in the blades according to traditional *** inboard region of the blade showed exceptional load-carrying capacity as it survived420%extreme loads in the *** this study,potential structural advantages by applying proposed structural features to large composite blades of multi-megawatt wind turbines were addressed.

关键词： wind energy rotor blade flatback local buckling extreme loads

wind Farm Support Vessel Extreme Roll Assessment While Docking in the Bohai Sea

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China Ocean Engineering 2021年第2期35卷 308-316页

作者： XU Xiao-sen Oleg Gaidai Oleh Karpa WANG Jun-lei YE Ren-chuan CHENG Yong Marine Equipment and Technology Institute Jiangsu University of Science and TechnologyZhenjiang 212100China School of Naval Architeture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China EPAM Systems Ukraine School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450001China

Robust prediction of extreme motions during wind farm support vessel(WFSV)operation is an important safety concern that requires further extensive research as offshore wind energy industry sector *** particular,it is important to study the safety of operation in random sea conditions during WFSV docking against the wind tower,while workers are able to get on the *** is performed by thrusting vessel fender against wind tower(an alternative docking way by hinging is not studied here).In this paper,the finite element software AQWA has been used to analyze vessel response due to hydrodynamic wave loads,acting on a specific maintenance ship under actual sea *** roll may occur during certain sea conditions,especially in the beam sea,posing a risk to the crew transfer *** Bohai Sea is the area of diverse industrial activities such as offshore oil production,wave and wind power generation,*** paper advocates a novel method for estimating extreme roll statistics,based on Monte Carlo simulations(or measurements).The ACER(averaged conditional exceedance rate)method and its modification are presented in brief detail in *** proposed methodology provides an accurate extreme value prediction,utilizing available data *** this study the estimated return level values,obtained by ACER method,are compared with the corresponding return level values obtained by Gumbel *** on the overall performance of the proposed method,it is concluded that the ACER method can provide more robust and accurate prediction of the extreme vessel *** described approach may be well used at the vessel design stage,while defining optimal boat parameters would minimize potential roll.

关键词： wind farm support vessel(WFSV) docking Monte Carlo extreme roll Gumbel distribution offshore wind turbine wind energy Bohai Sea

Analysis of Aerodynamic Load on Straight-bladed Vertical Axis wind Turbine

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Journal of Thermal Science 2014年第4期23卷 315-324页

作者： Qing’an LI Takao MAEDA Yasunari KAMADA Junsuke MURATA Toshiaki KAWABATA Kazuma FURUKAWA Division of System Engineering Mie University1577 Kurimamachiya-choTsuMie 514-8507JAPAN Division of Mechanical Engineering Mie University1577 Kurimamachiya-choTsuMie 514-8507JAPAN

This paper presents a wind tunnel experiment for the evaluation of energy performance and aerodynamic forces acting on a small straight-bladed vertical axis wind turbine(VAWT) depending on several values of tip speed ratio. In the present study, the wind turbine is a four-bladed VAWT. The test airfoil of blade is symmetry airfoil(NACA0021) with 32 pressure ports used for the pressure measurements on blade surface. Based on the pressure distributions which are acted on the surface of rotor blade measured during rotation by multiport pressure-scanner mounted on a hub, the power, tangential force, lift and drag coefficients which are obtained by pressure distribution are discussed as a function of azimuthally position. And then, the loads which are applied to the entire wind turbine are compared with the experiment data of pressure distribution. As a result, it is clarified that aerodynamic forces take maximum value when the blade is moving to upstream side, and become small and smooth at downstream side. The power and torque coefficients which are based on the pressure distribution are larger than that by torque meter.

关键词： wind Turbine wind energy Straight-bladed VAWT Tip Speed Ratio Pressure Distribution

Noise reduction effect of airfoil and small-scale rotor using serration trailing edge in a wind tunnel test

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Science China(Technological Sciences) 2017年第2期60卷 325-332页

作者： RYI Jaeha CHOI Jong-Soo Department of Aerospace Engineering Chungnam National University Daejeon 305-764 Korea

This paper discussed a noise reduction effect of airfoil and small-scale model rotor by using attached serration trailing edge in the wind tunnel test condition. In order to analyze the changes in the performance due to the inclusion of a serrated trailing edge designed to reduce noise, a 10 k W wind turbine rotor was equipped with a thin serrated trailing edge. The restrictive condition for the serrated trailing edge equipped with the using of a 2D airfoil was examined through the using of a wind tunnel experiment after studying existing restrictive condition and analyzing prior research on serrated trailing edges. The aerodynamic performance and noise reduction effect of a small-scale model were investigated with the using of a serrated trailing edge. Moreover, the noise levels from the experiment were considered that the noise prediction method could be used for a full-scale rotor. It is confirmed that noise reduction effect is compared with wind tunnel test data at the 2D airfoil and model rotor condition.

关键词： wind turbine rotor wind tunnel experiment wind energy trailing edge serration noise reduction effect

A Straight-bladed Vertical Axis wind Turbine with a Directed Guide Vane Row-Effect of Guide Vane Geometry on the Performance-

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Journal of Thermal Science 2009年第1期18卷 54-57页

作者： Manabu TAKAO Hideki KUMA Takao MAEDA Yasunari KAMADA Michiaki OKI Atsushi MINODA Department of Mechanical Engineering Matsue National College of Technology Department of Mechanical Engineering Mie University

The objective of this study is to show the effect of guide vane geometry on the performance. In order to overcome the disadvantages of vertical axis wind turbine, a straight-bladed vertical axis wind turbine （S-VAWT） with a directed guide vane row has been proposed and tested by the authors. According to previous studies, it was clarified that the performance of the turbine can be improved by means of the directed guide vane row. However, the guide vane geometry of S-VAWT has not been optimized so far. In order to clarify the effect of guide vanegeometry, the effects of setting angle and gap between rotor blade and guide vane on power coefticlent and start- ing characteristic were investigated in the experiments. The experimental study of the proposed wind turbine was carried out by a wind tunnel. The wind tunnel with a diameter of 1.8m is open jet type. The wind velocity is 8 m/s in the experiments. The rotor has three straight blades with a profile of NACA0018 and a chord length of 100 mm, a diameter of 0.6 m and a blade height of 0.7 m. The guide vane row consists of 3 arc plates.

关键词： fluid machinery wind energy vertical axis wind turbine guide vane

Super twisting sliding mode approach applied to voltage orientated control of a stand-alone induction generator

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Protection and Control of Modern Power Systems 2021年第1期6卷 233-241页

作者： Yacine Bendjeddou Abdelhakim Deboucha Larafi Bentouhami Elkheir Merabet Rachid Abdessemed Laboratory of electrical and materials engineering(LGEM) Higher School of Electrical and Energetic Engineering of Oran31000Bir El DjirAlgeria Ecole Supérieure des Sciences Appliquées d’Alger Electrical Engineering Department16000AlgiersAlgeria Department of electromechanical University of Bordj Bou Arréridj34000El AnceurAlgeria Laboratory LEB Department of Electrical EngineeringUniversity of Batna-205000FesdisAlgeria

To enhance the robustness and dynamic performance of a self-excited induction generator (SEIG) used in a stand-alone wind energy system (WES), a virtual flux oriented control (VFOC) based on nonlinear super-twisting sliding mode control (STSMC) is adopted. STSMC is used to replace the conventional proportional-integral-Fuzzy Logic Controller (PI-FLC) of the inner current control loops. The combination of the proposed control strategy with space vector modulation (SVM) applied to a PWM rectifier brings many advantages such as reduction in harmonics, and precise and rapid tracking of the references. The performance of the proposed control technique (STSMC-VFOC-SVM) is verified through simulations and compared with the traditional technique (PI-FLC-VFOC-SVM). It shows that the proposed method improves the dynamics of the system with reduced current harmonics. In addition, the use of a virtual flux estimator instead of a phase-locked loop (PLL) eliminates the line voltage sensors and thus increases the reliability of the system.

关键词： Self-excited induction generator Virtual flux oriented control Back-to-back converter Super twisting sliding mode control PI-fuzzy controller wind energy

Numerical experimental study on the potential climatic impacts oflarge-scale wind farms in China

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Advances in Climate Change Research 2019年第3期10卷 143-149页

作者： HUANG Jian-Bin LOU Peng-Kang SUN Hong-Wei LUO Yong ZHAO Zong-Ci Ministry o f Education Key Laboratory for Earth System Modeling Department o f Earth System ScienceTsinghua University100084BeijingChina

wind energy has been rapidly developed in China during the past decades and the installed capacity has been the largest in the world. In the future, utilization of wind power is still expected to carry out in China mainly with a large-scale centralized layout. Here, we examine the potential climatic impacts of large-scale windfarms associated with deployment scale in China using numerical experiments, in which four deployment scenarios were designed. These four scenarios represented relatively small- (484 GW), medium- (2165 GW) and large-scale (3490 GW and 5412 GW) installed wind power capacities, respectively. Results showed that turbulent kinetic energy, wind velocity, and air temperature varied consistently within those windfarms with the largest changes in turbine hub heights. Moreover, the above relatively large- scale windfarms could induce regional wanning with a maximum of above 0.8 °C in North China. This regional warming may be linked to an anomalous circulation pattern with a negative pressure anomaly center in Northeast China and a positive pressure anomaly center in the middle and lower reaches of the Yangtze-Huaihe River Basin.

关键词： Climatic impact Large-scale windfarms wind energy China WRF model

Mapping frequent spatio-temporal wind profile patterns using multi-dimensional sequential pattern mining

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International Journal of Digital Earth 2017年第3期10卷 238-256页

作者： Norhakim Yusof Raul Zurita-Milla Department of Geo-Information Processing Faculty of Geo-Information Science and Earth Observation(ITC)University of TwenteEnschedeThe Netherlands Department of Geoinformation Faculty of Geoinformation and Real EstateUniversiti Teknologi MalaysiaUTMJohor BahruMalaysia

Holistic understanding of wind behaviour over space,time and height is essential for harvesting wind energy *** study presents a novel approach for mapping frequent wind profile patterns using multidimensional sequential pattern mining(MDSPM).This study is illustrated with a time series of 24 years of European Centre for Medium-Range Weather Forecasts European Reanalysis-Interim gridded(0.125°×0.125°)wind data for the Netherlands every 6 h and at six height *** wind data were first transformed into two spatio-temporal sequence databases(for speed and direction,respectively).Then,the Linear time Closed Itemset Miner Sequence algorithm was used to extract the multidimensional sequential patterns,which were then visualized using a 3D wind rose,a circular histogram and a geographical *** patterns were further analysed to determine their wind shear coefficients and turbulence intensities as well as their spatial overlap with current areas with wind *** analysis identified four frequent wind profile *** of them highly suitable to harvest wind energy at a height of 128 m and 68.97%of the geographical area covered by this pattern already contains wind *** study shows that the proposed approach is capable of efficiently extracting meaningful patterns from complex spatio-temporal datasets.

关键词： Spatio-temporal data mining multi-dimensional sequential pattern mining wind shear coefficient turbulence intensity wind energy

System bias correction of short-term hub-height wind forecasts using the Kalman filter

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Protection and Control of Modern Power Systems 2021年第1期6卷 473-481页

作者： Jingjing Xu Ziniu Xiao Zhaohui Lin Ming Li International Center for Climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of ScienceBeijingChina State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Data61 Commonwealth Scientific and Industrial Research Organization(CSIRO)PerthAustralia

wind energy is a fluctuating source for power systems, which poses challenges to grid planning for the wind power industry. To improve the short-term wind forecasts at turbine height, the bias correction approach Kalman filter (KF) is applied to 72-h wind speed forecasts from the WRF model in Zhangbei wind farm for a period over two years. The KF approach shows a remarkable ability in improving the raw forecasts by decreasing the root-mean-square error by 16% from 3.58 to 3.01 m s−1, the mean absolute error by 14% from 2.71 to 2.34 m s−1, the bias from 0.22 to − 0.19 m s−1, and improving the correlation from 0.58 to 0.66. The KF significantly reduces random errors of the model, showing the capability to deal with the forecast errors associated with physical processes which cannot be accurately handled by the numerical model. In addition, the improvement of the bias correction is larger for wind speeds sensitive to wind power generation. So the KF approach is suitable for short-term wind power prediction.

关键词： wind forecasts wind energy Numerical model Bias correction Kalman filter Atmospheric boundary layer