風(fēng)力發(fā)電機葉片：設(shè)計規(guī)范、材料、制作工藝、結(jié)構(gòu)強度、雷電保護(hù)、認(rèn)證規(guī)范運輸運行中的質(zhì)檢標(biāo)準(zhǔn)

Structural collapse of a wind turbine blade. Part A: Static test and equivalent single layered models  Composites Part A: Applied Science and ManufacturingThe overall objective is a top-down approach to structural instability phenomena in wind turbine blades, which is used to identify the physics governing the ultimate strength of a generic wind turbine blade under a flap-wise static test. The work is concerned with the actual testing and the adoption of a phenomenological approach, and a discussion is conducted to assess and evaluate the wind turbine blade response during loading and after collapse by correlating experimental findings with numerical model predictions. The ultimate strength of the blade studied is governed by instability phenomena in the form of delamination and buckling. Interaction between both instability phenomena occurs causing a progressive collapse of the blade structure.Linear vibration analysis of rotating wind-turbine blade Current Applied PhysicsIn the wind-turbine design, linear vibration analysis of the wind-turbine blade should be performed to get vibratory characteristics and to avoid structural resonance. EOM (equations of motion) for the blade are derived and vibratory characteristics of a rotating blade are observed and discussed in this work. Linear vibration analysis requires the linearized EOM with DOF (degree of freedom). For the system with large DOF, the derivation and linearization of EOM are very tedious and difficult. Constrained multi-body technique is employed to derive EOMs to alleviate this burden. It is well known that natural frequencies and corresponding modes vary as rotating velocity changes. At the operating condition with relatively high rotating velocity, almost all commercial programs cannot predict the blade frequencies accurately. Numerical problems were solved to verify the accuracy of the proposed method. Through the numerical problems, this work shows that the proposed method is useful to predict the vibratory behavior of the rotating blade. Furthermore, a numerical problem was solved to check the numerical accuracy of commercial program results within operating region.Aero-elastic behavior of a flexible blade for wind turbine application: A 2D computational study  EnergyThis paper presents a computational study into the static aeroelastic response of a 2D wind turbine airfoil under varying wind conditions. An efficient and accurate code that couples the X-Foil software for computation of airfoil aerodynamics and the MATLAB PDE toolbox for computation of the airfoil deformation is developed for the aero-elastic computations. The code is validated qualitatively against computational results in literature. The impact of a flexibility of the airfoil is studied for a range of design parameters including the free stream velocity, pitch angle, airfoil thickness, and airfoil camber. Static aero-elastic effects have the potential to improve lift and the lift over drag ratio at off-design wind speed conditions. Flexibility delays stall to a large pitch angle, increasing the operating range of a flexible blade airfoil. With increased thickness the airfoil deformation decrease only linearly.Technical cost modelling for a generic 45-m wind turbine blade producedby vacuum infusion (VI)  Renewable EnergyA detailed technical cost analysis has been conducted on a generic 45-m wind turbine blade manufactured using the vacuum infusion (VI) process, in order to isolate areas of significant cost savings. The analysis has focused on a high labour cost environment such as the UK and investigates the influence of varying labour costs, programme life, component area, deposition time, cure time and reinforcement price with respect to production volume. A split of the cost centres showed the dominance of material and labour costs at approximately 51% and 41%, respectively. Due to the dominance of materials, it was shown that fluctuations in reinforcement costs can easily increase or decrease the cost of a turbine blade by up to 14%. Similarly, improving material deposition time by 2 h can save approximately 5% on the total blade cost. However, saving 4 h on the cure cycle only has the potential to provide a 2% cost saving.A cost and performance comparison of LRTM and VI for the manufacture of large scale wind turbine blades  Renewable EnergyLight resin transfer moulding (LRTM) has been developed as an alternative to vacuum infusion (VI) but a direct comparison between the two processes is needed to quantify any advantages. This paper uses a technical cost model and an empirical study to show the potential financial and performance benefits of LRTM for manufacture of a generic 40 m wind turbine blade shell. The use of LRTM when compared to VI demonstrated a possible 3% cost saving, improved dimensional stability (5.5%), and reductions in resin wastage (3%) and infusion time (25%). A decrease in internal void formation (0.9%) resulted in an increase in mechanical performance (<4%) for LRTM moulded parts.Power curve control in micro wind turbine design  In this work, a micro wind turbine will be designed and built for a series of wind tunnel tests (rotor dynamics and Wind Turbine (WT) start-up velocity). Its design stems from an original numerical code, developed by the authors, based on the Blade Element Momentum (BEM) Theory. From classic design criteria, having evaluated all the geometric characteristics, an innovative methodology will be shown for controlling the power curve of the wind turbine. Indications will be supplied in order to modify various sections of the power curve and so as to design the turbine according to its practical application.微小型風(fēng)力發(fā)電機組的輸出電能能源曲線控制Performance effects of attachment on blade on a straight-bladed vertical axis wind turbine 直線型垂直軸風(fēng)力發(fā)電機葉片工作效能及其附件選配Current Applied PhysicsRecently, many straight-bladed vertical axis wind turbines (SB-VAWT) are installed in community, urban and high mountain areas as an independent power supply. However, in cold climates, icing, snow and other attachments on the blade surface may affect turbine performance. In this study, the condition of rime-type icing on the leading edge of blade surface was simulated by clay, and the effects on the rotation and power performance were measured by wind tunnel tests and discussed. The results show that the attachment reduced the steady revolution and power coefficient of the SB-VAWT, and the reduction rate increased as the weight of the attachment and wind speed increased.A methodology for the structural analysis of composite wind turbine blades under geometric and material induced instabilities  Computers & StructuresThe objective of this work is to develop a modeling strategy for the structural analysis of large three-dimensional laminated composite structures undergoing geometric and material induced instability. A sub-modeling approach is used with multiple mixed-mode linear-softening cohesive elements and linear-elastic solid-shell elements through the thickness. A localized sub-plane control strategy is adopted for tracking multiple crack formations and the propagation of multiple delamination fronts. Simple element and solver benchmarks are used to demonstrate the adopted methods. Finally, the adopted methods are demonstrated in an engineering case study of a generic laminated composite wind turbine blade.Structural collapse of a wind turbine blade. Part B: Progressive interlaminar failure models  Composites Part A: Applied Science and ManufacturingThe objective of this paper is to present a geometrical nonlinear and interlaminar progressive failure finite element analysis of a generic wind turbine blade undergoing a static flap-wise load and comparisons with experimental findings. It is found that the predictive numerical models show excellent correlation with the experimental findings and observations in the pre-instability response. Consequently, the ultimate strength of the wind turbine blade studied is governed by a delamination and buckling coupled phenomenon, which results in a chain of events and sudden structural collapse with compressive fibre failure in the delaminated flange material. Finally, a parametric study of the critical load factors with respect to various delamination sizes and positions inside the compressive flange of the wind turbine blade is presented.An adaptive neuro-fuzzy inference system approach for prediction of tip speed ratio in wind turbines  Expert Systems with ApplicationsThis paper introduces an adaptive neuro-fuzzy inference system (ANFIS) model to predict the tip speed ratio (TSR) and the power factor of a wind turbine. This model is based on the parameters for LS-1 and NACA4415 profile types with 3 and 4 blades. In model development, profile type, blade number, Schmitz coefficient, end loss, profile type loss, and blade number loss were taken as input variables, while the TSR and power factor were taken as output variables. After a successful learning and training process, the proposed model produced reasonable mean errors. The results indicate that the errors of ANFIS models in predicting TSR and power factor are less than those of the ANN method.Optimal blade shape of a modified Savonius turbine using an obstacle shielding the returning blade Energy Conversion and ManagementDue to the worldwide energy crisis, research and development activities in the field of renewable energy have been considerably increased in many countries. Wind energy is becoming particularly important. Although considerable progress have already been achieved, the available technical design is not yet adequate to develop reliable wind energy converters for conditions corresponding to low wind speeds and urban areas. The Savonius turbine appears to be particularly promising for such conditions, but suffers from a poor efficiency. The present study considers a considerably improved design in order to increase the output power of a classical Savonius turbine. In previous works, the efficiency of the classical Savonius turbine has been increased by placing in an optimal manner an obstacle plate shielding the returning blade. The present study now aims at improving further the output power of the Savonius turbine as well as the static torque, which measures the self-starting capability of the turbine. In order to achieve both objectives, the geometry of the blade shape (skeleton line) is now optimized in presence of the obstacle plate. Six free parameters are considered in this optimization process, realized by coupling an in-house optimization library (OPAL, relying in the present case on Evolutionary Algorithms) with an industrial flow simulation code (ANSYS-Fluent). The target function is the output power coefficient. Compared to a standard Savonius turbine, a relative increase of the power output coefficient by almost 40% is finally obtained at  = 0.7. The performance increase exceeds 30% throughout the useful operating range. Finally, the static torque is investigated and found to be positive at any angle, high enough to obtain self-starting conditions.The inception of OMA in the development of modal testing technology for wind turbines  Mechanical Systems and Signal ProcessingWind turbines are immense, flexible structures with aerodynamic forces acting on the rotating blades at harmonics of the turbine rotational frequency. These harmonics are comparable to the modal frequencies of the structure. Predicting and experimentally measuring the modal frequencies of wind turbines have been important to their successful design and operation. Performing modal tests on wind turbine structures over 100 m tall is a substantial challenge, which has inspired innovative developments in modal test technology. For wind turbines, a further complication is that the modal frequencies are dependent on the turbine rotation speed. The history and development of a new technique for acquiring the modal parameters using output-only response data, called the Natural Excitation Technique (NExT), will be reviewed, showing historical tests and techniques. The initial attempts at output-only modal testing began in the late 1980s with the development of NExT in the 1990s. NExT was a predecessor to Operational Modal Analysis (OMA), developed to overcome these challenges of testing immense structures excited with natural environmental inputs. We will trace the difficulties and successes of wind turbine modal testing from 1982 to the present.Optimization of Savonius turbines using an obstacle shielding the returning blade  Due to the worldwide energy crisis, research and development activities in the field of renewable energy have been considerably increased in many countries. In Germany, wind energy is becoming particularly important. Although considerable progress has already been achieved, the available technical design is not yet adequate to develop reliable wind energy converters for conditions corresponding to low wind speeds and urban areas. The Savonius turbine appears to be particularly promising for such conditions, but suffers from a poor efficiency. The present study considers a considerably improved design in order to increase the output power of a Savonius turbine with either two or three blades. In addition, the improved design leads to a better self-starting capability. To achieve these objectives, the position of an obstacle shielding the returning blade of the Savonius turbine and possibly leading to a better flow orientation toward the advancing blade is optimized. This automatic optimization is carried out by coupling an in-house optimization library (OPAL) with an industrial flow simulation code (ANSYS-Fluent). The optimization process takes into account the output power coefficient as target function, considers the position and the angle of the shield as optimization parameters, and relies on Evolutionary Algorithms. A considerable improvement of the performance of Savonius turbines can be obtained in this manner, in particular a relative increase of the power output coefficient by more than 27%. It is furthermore demonstrated that the optimized configuration involving a two-blade rotor is better than the three-blade design.Acoustic measurement for 12% scaled model of NREL Phase VI wind turbine by using beamforming  Current Applied PhysicsWind tunnel test for the 12% scaled model of NREL Phase VI wind turbine was conducted at Korea Aerospace Research Institute (KARI) low speed wind tunnel. Test condition for the scaled model was decided to match the blade tip mach number with real scale model test which was conducted at NASA Ames (80 × 120) Tunnel. Aerodynamic performance represented by torque of the blades was measured by using the torque sensor installed in rotating shaft and compared with real scale model test results. Acoustic noise for scaled model was also measured at closed type test section with acoustic array of 144 microphones. Time based beamforming method to identify the rotating noise source position was applied to analyze the test results. 1/3 octave band was used in post processing for various wind speeds. Test results shows that the main acoustic noise source position moves toward the blade tip as frequency increases and the noise level at low frequency below 2 kHz has much higher when the blade is in stall condition.低溫天氣情況下，結(jié)冰對于曲面葉片的影響衡量與評估Measurement method and results of ice adhesion force on the curved surface of a wind turbine blade  Experimental adhesion force measurements were conducted on accumulated ice on the leading edge of a scaled wind turbine blade in both glaze and rime icing regimes. An apparatus was first designed for specifically measuring the adhesion force of ice on a curved surface at climatic temperature where a vertical force was applied to the mounted structure in the test apparatus. Adhesion force measurements were measured and adhesion pressure calculated for plain and ice-mitigated test specimens. Results are presented for the increase in force of ice adhesion over a curved surface area in proportion to degree centigrade decrease in temperature.Optimization of wind turbine energy and power factor with an evolutionary computation algorithm 結(jié)合風(fēng)電場個性化特殊設(shè)計法的葉片的優(yōu)化設(shè)計通用算法An evolutionary computation approach for optimization of power factor and power output of wind turbines is discussed. Data-mining algorithms capture the relationships among the power output, power factor, and controllable and non-controllable variables of a 1.5 MW wind turbine. An evolutionary strategy algorithm solves the data-derived optimization model and determines optimal control settings. Computational experience has demonstrated opportunities to improve the power factor and the power output by optimizing set points of blade pitch angle and generator torque. It is shown that the pitch angle and the generator torque can be controlled to maximize the energy capture from the wind and enhance the quality of the power produced by the wind turbine with a DFIG generator. These improvements are in the presence of reactive power remedies used in modern wind turbines. The concepts proposed in this paper are illustrated with the data collected at an industrial wind farm.Review of state of the art in smart rotor control research for wind turbines Progress in Aerospace SciencesThis article presents a review of the state of the art and present status of active aeroelastic rotor control research for wind turbines. Using advanced control concepts to reduce loads on the rotor can offer great reduction to the total cost of wind turbines. With the increasing size of wind turbine blades, the need for more sophisticated load control techniques has induced the interest for locally distributed aerodynamic control systems with build-in intelligence on the blades. Such concepts are often named in popular terms smart structures or smart rotor control. The review covers the full span of the subject, starting from the need for more advanced control systems emerging from the operating conditions of modern wind turbines and current load reduction control capabilities. An overview of available knowledge and up-to date progress in application of active aerodynamic control is provided, starting from concepts, methods and achieved results in aerospace and helicopter research. Moreover, a thorough analysis on different concepts for smart rotor control applications for wind turbines is performed, evaluating available options for aerodynamic control surfaces, actuators (including smart materials), sensors and control techniques. Next, feasibility studies for wind turbine applications, preliminary performance evaluation and novel computational and experimental research approaches are reviewed. The potential of load reduction using smart rotor control concepts is shown and key issues are discussed. Finally, existing knowledge and future requirements on modeling issues of smart wind turbine rotors are discussed. This study provides an overview of smart rotor control for wind turbines, discusses feasibility of future implementation, quantifies key parameters and shows the challenges associated with such an approach.Horizontal axis wind turbine working at maximum power coefficient continuously  水平軸大型葉片在滿載/最大輸出條件下的連續(xù)工作效率The performance of a horizontal axis wind turbine continuously operating at its maximum power coefficient was evaluated by a calculation code based on Blade Element Momentum (BEM) theory. It was then evaluated for performance and Annual Energy Production (AEP) at a constant standard rotational velocity as well as at a variable velocity but at its maximum power coefficient. The mathematical code produced a power coefficiency curve which showed that notwithstanding fur