WorldWideScience

Sample records for wind machine performance

  1. Performance analysis of a composite dual-winding reluctance machine

    International Nuclear Information System (INIS)

    Anih, Linus U.; Obe, Emeka S.

    2009-01-01

    The electromagnetic energy conversion process of a composite dual-winding asynchronous reluctance machine is presented. The mechanism of torque production is explained using the magnetic fields distributions. The dynamic model developed in dq-rotor reference frame from first principles depicts the machine operation and response to sudden load change. The device is self-starting in the absence of rotor conductors and its starting current is lower than that of a conventional induction machine. Although the machine possesses salient pole rotors, it is clearly shown that its performance is that of an induction motor operating at half the synchronous speed. Hence the device produces synchronous torque while operating asynchronously. Simple tests were conducted on a prototype demonstration machine and the results obtained are seen to be in tune with the theory and the steady-state calculations.

  2. Permanent magnet machines with air gap windings and integrated teeth windings

    Energy Technology Data Exchange (ETDEWEB)

    Alatalo, M [Chalmers Univ. of Technology, Goeteborg (Sweden). School of Electrical and Computer Engineering

    1996-06-01

    The Thesis deals with axial and radial flux permanent magnet machines with air gap windings and an integrated teeth winding. The aim is to develop a machine that produces a high torque per unit volume with as low losses as possible. The hypothesis is that an advanced three-phase winding, magnetized by a permanent magnet rotor should be better than other machine topologies. The finite element method is used to find favourable dimensions of the slotless winding, the integrated teeth winding and the permanent magnet rotor. Three machines were built and tested in order to verify calculations. It can be concluded that the analysis method shows good agreement with the calculated and the measured values of induced voltage and torque. The experiments showed that the slotless machine with NdFeB-magnets performs approximately like the slotted machine. A theoretical comparison of axial flux topology to radial flux topology showed that the torque production of the inner rotor radial flux machine is superior to that of the axial flux machine. An integrated teeth winding based on iron powder teeth glued to the winding was studied. The force density of a pole with integrated teeth is around three times the force density of a slotless pole. A direct drive wind power generator of 6.4 kW with integrated teeth can have the same power losses and magnet weight as a transversal flux machine. Compared to a standard induction machine the integrated teeth machine had approximately 2.5 times the power capacity of the induction machine with the same power losses and outer volume. 39 refs

  3. An automated coil winding machine for the SSC dipole magnets

    International Nuclear Information System (INIS)

    Kamiya, S.; Iwase, T.; Inoue, I.; Fukui, I.; Ishida, K.; Kashiwagi, S.; Sato, Y.; Yoshihara, T.; Yamamoto, S.; Johnson, E.; Gibson, C.

    1990-01-01

    The authors have finished the preliminary design of a fully automated coil winding machine that can be used to manufacture the large number of SSC dipole magnets. The machine aims to perform all coil winding operations including coil parts inserting without human operators at a high productive rate. The machine is composed of five industrial robots. In order to verify the design, they built a small winding machine using an industrial robot and successfully wound a 1 meter long coil using SSC dipole magnet wire. The basic design for the full length coil and the robot winding technique are described in this paper. A fully automated coil winding machine using standard industrial components would be very useful if duplicate production lines are used. 5 figs., 1 tab

  4. Variable geometry Darrieus wind machine

    Science.gov (United States)

    Pytlinski, J. T.; Serrano, D.

    1983-08-01

    A variable geometry Darrieus wind machine is proposed. The lower attachment of the blades to the rotor can move freely up and down the axle allowing the blades of change shape during rotation. Experimental data for a 17 m. diameter Darrieus rotor and a theoretical model for multiple streamtube performance prediction were used to develop a computer simulation program for studying parameters that affect the machine's performance. This new variable geometry concept is described and interrelated with multiple streamtube theory through aerodynamic parameters. The computer simulation study shows that governor behavior of a Darrieus turbine can not be attained by a standard turbine operating within normally occurring rotational velocity limits. A second generation variable geometry Darrieus wind turbine which uses a telescopic blade is proposed as a potential improvement on the studied concept.

  5. Performance Comparison of Conventional Synchronous Reluctance Machines and PM-Assisted Types with Combined Star–Delta Winding

    Directory of Open Access Journals (Sweden)

    Mohamed Nabil Fathy Ibrahim

    2017-09-01

    Full Text Available This paper compares four prototype Synchronous Reluctance Motors (SynRMs having an identical geometry of iron lamination stacks in the stator and rotor. Two different stator winding layouts are employed: a conventional three-phase star connection and a combined star–delta winding. In addition, two rotors are considered: a conventional rotor without magnets and a rotor with ferrite magnets. The performance of the four SynRMs is evaluated using a two-dimensional (2D Finite Element Model (FEM. For the same copper volume and current, the combined star–delta-connected stator with Permanent Magnets (PMs in the rotor corresponds to an approximately 22% increase in the output torque at rated current and speed compared to the conventional machine. This improvement is mainly thanks to adding ferrite PMs in the rotor as well as to the improved winding factor of the combined star–delta winding. The torque gain increases up to 150% for low current. Moreover, the rated efficiency is 93.60% compared to 92.10% for the conventional machine. On the other hand, the impact on the power factor and losses of SynRM when using the star–delta windings instead of the star windings is merely negligible. The theoretical results are experimentally validated using four identical prototype machines with identical lamination stacks but different rotors and winding layouts.

  6. Optimization of electrical parameters of windings used in axial flux electrical machines

    International Nuclear Information System (INIS)

    Uhrik, M.

    2012-01-01

    This paper deals with shape optimization of windings used in electrical machines with disc type construction. These machines have short axial length what makes them suitable for use in small wind-power turbines or in-wheel traction drives. Disc type construction of stator offers more possibilities for winding arrangements than are available in classical machines with cylindrical construction. To find out the best winding arrangement for the novel disc type machine construction a series of analytical calculations, simulations and experimental measurements were performed. (Authors)

  7. Study of the AC machines winding having fractional q

    Science.gov (United States)

    Bespalov, V. Y.; Sidorov, A. O.

    2018-02-01

    The winding schemes with a fractional numbers of slots per pole and phase q have been known and used for a long time. However, in the literature on the low-noise machines design there are not recommended to use. Nevertheless, fractional q windings have been realized in many applications of special AC electrical machines, allowing to improve their performance, including vibroacoustic one. This paper deals with harmonic analysis of windings having integer and fractional q in permanent magnet synchronous motors, a comparison of their characteristics is performed, frequencies of subharmonics are revealed. Optimal winding pitch design is found giving reduce the amplitudes of subharmonics. Distribution factors for subharmonics, fractional and high-order harmonics are calculated, results analysis is represented, allowing for giving recommendations how to calculate distribution factors for different harmonics when q is fractional.

  8. Design and optimize of 3-axis filament winding machine

    Science.gov (United States)

    Quanjin, Ma; Rejab, M. R. M.; Idris, M. S.; Bachtiar, B.; Siregar, J. P.; Harith, M. N.

    2017-10-01

    Filament winding technique is developed as the primary process for composite cylindrical structures fabrication at low cost. Fibres are wound on a rotating mandrel by a filament winding machine where resin impregnated fibres pass through a pay-out eye. This paper aims to develop and optimize a 3-axis, lightweight, practical, efficient, portable filament winding machine to satisfy the customer demand, which can fabricate pipes and round shape cylinders with resins. There are 3 main units on the 3-axis filament winding machine, which are the rotary unit, the delivery unit and control system unit. Comparison with previous existing filament winding machines in the factory, it has 3 degrees of freedom and can fabricate more complex shape specimens based on the mandrel shape and particular control system. The machine has been designed and fabricated on 3 axes movements with control system. The x-axis is for movement of the carriage, the y-axis is the rotation of mandrel and the z-axis is the movement of the pay-out eye. Cylindrical specimens with different dimensions and winding angles were produced. 3-axis automated filament winding machine has been successfully designed with simple control system.

  9. Four wind speed multi-step forecasting models using extreme learning machines and signal decomposing algorithms

    International Nuclear Information System (INIS)

    Liu, Hui; Tian, Hong-qi; Li, Yan-fei

    2015-01-01

    Highlights: • A hybrid architecture is proposed for the wind speed forecasting. • Four algorithms are used for the wind speed multi-scale decomposition. • The extreme learning machines are employed for the wind speed forecasting. • All the proposed hybrid models can generate the accurate results. - Abstract: Realization of accurate wind speed forecasting is important to guarantee the safety of wind power utilization. In this paper, a new hybrid forecasting architecture is proposed to realize the wind speed accurate forecasting. In this architecture, four different hybrid models are presented by combining four signal decomposing algorithms (e.g., Wavelet Decomposition/Wavelet Packet Decomposition/Empirical Mode Decomposition/Fast Ensemble Empirical Mode Decomposition) and Extreme Learning Machines. The originality of the study is to investigate the promoted percentages of the Extreme Learning Machines by those mainstream signal decomposing algorithms in the multiple step wind speed forecasting. The results of two forecasting experiments indicate that: (1) the method of Extreme Learning Machines is suitable for the wind speed forecasting; (2) by utilizing the decomposing algorithms, all the proposed hybrid algorithms have better performance than the single Extreme Learning Machines; (3) in the comparisons of the decomposing algorithms in the proposed hybrid architecture, the Fast Ensemble Empirical Mode Decomposition has the best performance in the three-step forecasting results while the Wavelet Packet Decomposition has the best performance in the one and two step forecasting results. At the same time, the Wavelet Packet Decomposition and the Fast Ensemble Empirical Mode Decomposition are better than the Wavelet Decomposition and the Empirical Mode Decomposition in all the step predictions, respectively; and (4) the proposed algorithms are effective in the wind speed accurate predictions

  10. Determination of performance parameters of vertical axis wind turbines in wind tunnel

    Directory of Open Access Journals (Sweden)

    Nguyen Van Bang

    2017-01-01

    Full Text Available The paper deals with the determination of the performance parameters of a small vertical axis wind turbines (VAWT, which operate by the utilization of drag forces acting on the blades of the turbine. The performance was evaluated by investigating the electrical power output and torque moment of the wind machine. Measurements were performed on the full-scale model and the experimental data are assessed and compared to other types of wind turbines, with respect to its purpose.

  11. Optimal Pole Number and Winding Designs for Low Speed–High Torque Synchronous Reluctance Machines

    Directory of Open Access Journals (Sweden)

    Gurutz Artetxe

    2018-01-01

    Full Text Available This paper studies the feasibility of using synchronous reluctance machines (SynRM for low speed–high torque applications. The challenge lies in obtaining low torque ripple values, high power factor, and, especially, high torque density values, comparable to those of permanent magnet synchronous machines (PMSMs, but without resorting to use permanent magnets. A design and calculation procedure based on multistatic finite element analysis is developed and experimentally validated via a 200 Nm, 160 rpm prototype SynRM. After that, machine designs with different rotor pole and stator slot number combinations are studied, together with different winding types: integral-slot distributed-windings (ISDW, fractional-slot distributed-windings (FSDW and fractional-slot concentrated-windings (FSCW. Some design criteria for low-speed SynRM are drawn from the results of the study. Finally, a performance comparison between a PMSM and a SynRM is performed for the same application and the conclusions of the study are summarized.

  12. Characterization of sound emitted by wind machines used for frost control

    Energy Technology Data Exchange (ETDEWEB)

    Gambino, V.; Gambino, T. [Aercoustics Engineering Ltd., Toronto, ON (Canada); Fraser, H.W. [Ontario Ministry of Agriculture, Food and Rural Affairs, Vineland, ON (Canada)

    2007-07-01

    Wind machines are used in Niagara-on-the-Lake to protect cold-sensitive crops against cold injury during winter's extreme cold temperatures,spring's late frosts and autumn's early frosts. The number of wind machines in Ontario has about doubled annually from only a few in the late 1990's, to more than 425 in 2006. They are not used for generating power. Noise complaints have multiplied as the number of wind machines has increased. The objective of this study was to characterize the sound produced by wind machines; learn why residents are annoyed by wind machine noise; and suggest ways to possibly reduce sound emissions. One part of the study explored acoustic emission characteristics, the sonic differences of units made by different manufacturers, sound propagation properties under typical use atmospheric conditions and low frequency noise impact potential. Tests were conducted with a calibrated Larson Davis 2900B portable spectrum analyzer. Sound was measured with a microphone whose frequency response covered the range 4 Hz to 20 kHz. The study examined and found several unique acoustic properties that are characteristic of wind machines. It was determined that noise from wind machines is due to both aerodynamic and mechanical effects, but aerodynamic sounds were found to be the most significant. It was concluded that full range or broadband sounds manifest themselves as noise components that extend throughout the audible frequency range from the bladepass frequency to upwards of 1000 Hz. The sound spectrum of a wind machine is full natural tones and impulses that give it a readily identifiable acoustic character. Atmospheric conditions including temperature, lapse rate, relative humidity, mild winds, gradients and atmospheric turbulence all play a significant role in the long range outdoor propagation of sound from wind machines. 6 refs., 6 figs.

  13. Design and realization on function of pre-forming and continuous winding for HT-7U special winding machine

    International Nuclear Information System (INIS)

    Yu Jie; Gao Daming; Wen Jun; Zhu Wenhua; Cheng Leping; Tao Yuming

    2000-05-01

    The winding machine is one of the critical facilities for R and D of HT-7U construction. The machine mainly consists of five parts, CICC pay-off spool, a four-rollers straightening assembly, a four-roller forming/bending assembly, continuous winding structure and CNC control system with three-axis CNC control. The facility is needed for CICC magnet fabrication of HT-7U. The main requirements of the winding machine are: continuous winding to reduce number of joints inside the coils; pre-forming CICC conductor to avoid winding with tension; suitable for all TF and PF coils within the scope of various coil shape and dimension limit; improving the configuration tolerance, specially flatness of the CICC conductor. The author emphasizes on the design and realization on function of Pre-forming and Continuous Winding for HT-7U special winding machine. The winding machine with high accuracy has just been developed and applied to the construction of HT-7U model coils

  14. Development of electric machines with superconducting windings

    International Nuclear Information System (INIS)

    Glebov, I.A.; Novitskij, V.G.

    1977-01-01

    Some studies are discussed performed in the USSR with the aim to develop the most promising electrical machines with superconducting windings, i.e. powerful (more than 1 MW) cryoturbogenerators for power heat and nuclear plants, electric motors of more than 10,000 kW, reverse systems of an electric driver and unipolar generators for electrolysis industry. The design and performances of the simulator of a 1500 kW cryoturbogenerator are given. Problems of coooling and oscillations of the simulator rotor are considered

  15. An improved excitation control technique of three-phase induction machine operating as dual winding generator for micro-wind domestic application

    International Nuclear Information System (INIS)

    Chatterjee, Arunava; Chatterjee, Debashis

    2015-01-01

    Highlights: • A three-phase induction machine working as single phase generator is studied. • The generator is assisted by an inverter and photovoltaic panel for excitation. • Proposed control involves operating the machine as balanced two-phase generator. • Torque pulsations associated with unbalanced phase currents are minimized. • The generator can be used for grid-isolated micro-wind power generation. - Abstract: Single-phase generation schemes are widely utilized for harnessing wind power in remote and grid secluded applications. This paper presents a novel control methodology for a three-phase induction machine working as a single-phase dual winding induction generator. Three-phase induction machines providing single-phase output with proper control strategy can be beneficial in grid secluded micro-wind energy conversion systems compared to single-phase induction generators. Three-phase induction machines operating in single-phase mode are mostly excited asymmetrically to provide single-phase power leading to unbalanced current flow in the stator windings causing heating and insulation breakdown. The asymmetrical excitation also initiates torque pulsations which results in additional stress and vibration at the machine shaft and bearings degrading the machine performance. The proposed control is chiefly aimed to minimize this unbalance. The variable excitation required for the proposed generator is provided through a single-phase inverter with photovoltaic panels. The suitability for such a generator along with its control is tested with appropriate simulations and experimental results. The induction generator with the proposed control strategy is expected to be useful in remote and grid isolated households as a standalone source of single-phase electrical power

  16. Unconventional wind machine

    International Nuclear Information System (INIS)

    Sheff, J.R.

    1979-01-01

    It is the purpose of this paper to introduce an unconventional wind machine which has economics comparable with nuclear power and is already available in the public market place. Specifically, up to about 17 MWE could be saved for other uses such as sale in most 1000 MWE plants of any type - nuclear, oil, gas, peat, or wood - which use conventional electrically driven fans in their cooling towers. 10 refs

  17. Multi-phase alternative current machine winding design | Khan ...

    African Journals Online (AJOL)

    ... single-phase to 18-phase excitation. Experimental results of a five-phase induction machine supplied from a static five-phase supply are provided to support the proposed design. Keywords: AC machine, Multi-phase machine, Stator winding, Five-phase. International Journal of Engineering, Science and Technology, Vol.

  18. MACHINE-TRANSFORMER UNITS FOR WIND TURBINES

    Directory of Open Access Journals (Sweden)

    V.I. Panchenko

    2016-03-01

    Full Text Available Background. Electric generators of wind turbines must meet the following requirements: they must be multi-pole; to have a minimum size and weight; to be non-contact, but controlled; to ensure the maximum possible output voltage when working on the power supply system. Multipole and contactless are relatively simply realized in the synchronous generator with permanent magnet excitation and synchronous inductor generator with electromagnetic excitation; moreover the first one has a disadvantage that there is no possibility to control the output voltage, and the second one has a low magnetic leakage coefficient with the appropriate consequences. Purpose. To compare machine dimensions and weight of the transformer unit with induction generators and is an opportunity to prove their application for systems with low RMS-growth rotation. Methodology. A new design of the electric inductor machine called in technical literature as machine-transformer unit (MTU is presented. A ratio for estimated capacity determination of such units is obtained. Results. In a specific example it is shown that estimated power of MTU may exceed the same one for traditional synchronous machines at the same dimensions. The MTU design allows placement of stator coil at some distance from the rotating parts of the machine, namely, in a closed container filled with insulating liquid. This will increase capacity by means of more efficient cooling of coil, as well as to increase the output voltage of the MTU as a generator to a level of 35 kV or more. The recommendations on the certain parameters selection of the MTU stator winding are presented. The formulas for copper cost calculating on the MTU field winding and synchronous salient-pole generator are developed. In a specific example it is shown that such costs in synchronous generator exceed 2.5 times the similar ones in the MTU.

  19. Solar wind classification from a machine learning perspective

    Science.gov (United States)

    Heidrich-Meisner, V.; Wimmer-Schweingruber, R. F.

    2017-12-01

    It is a very well known fact that the ubiquitous solar wind comes in at least two varieties, the slow solar wind and the coronal hole wind. The simplified view of two solar wind types has been frequently challenged. Existing solar wind categorization schemes rely mainly on different combinations of the solar wind proton speed, the O and C charge state ratios, the Alfvén speed, the expected proton temperature and the specific proton entropy. In available solar wind classification schemes, solar wind from stream interaction regimes is often considered either as coronal hole wind or slow solar wind, although their plasma properties are different compared to "pure" coronal hole or slow solar wind. As shown in Neugebauer et al. (2016), even if only two solar wind types are assumed, available solar wind categorization schemes differ considerably for intermediate solar wind speeds. Thus, the decision boundary between the coronal hole and the slow solar wind is so far not well defined.In this situation, a machine learning approach to solar wind classification can provide an additional perspective.We apply a well-known machine learning method, k-means, to the task of solar wind classification in order to answer the following questions: (1) How many solar wind types can reliably be identified in our data set comprised of ten years of solar wind observations from the Advanced Composition Explorer (ACE)? (2) Which combinations of solar wind parameters are particularly useful for solar wind classification?Potential subtypes of slow solar wind are of particular interest because they can provide hints of respective different source regions or release mechanisms of slow solar wind.

  20. Probabilistic forecasting of wind power generation using extreme learning machine

    DEFF Research Database (Denmark)

    Wan, Can; Xu, Zhao; Pinson, Pierre

    2014-01-01

    an extreme learning machine (ELM)-based probabilistic forecasting method for wind power generation. To account for the uncertainties in the forecasting results, several bootstrapmethods have been compared for modeling the regression uncertainty, based on which the pairs bootstrap method is identified......Accurate and reliable forecast of wind power is essential to power system operation and control. However, due to the nonstationarity of wind power series, traditional point forecasting can hardly be accurate, leading to increased uncertainties and risks for system operation. This paper proposes...... with the best performance. Consequently, a new method for prediction intervals formulation based on theELMand the pairs bootstrap is developed.Wind power forecasting has been conducted in different seasons using the proposed approach with the historical wind power time series as the inputs alone. The results...

  1. DIAGNOSIS OF THE WINDING MACHINE IN THE OLD SHAFT WITH SKIP IN LONEA MINING PLANT

    Directory of Open Access Journals (Sweden)

    Răzvan Bogdan ITU

    2017-05-01

    Full Text Available To study the operation of the winding machine in the Old Shaft with Skip in Lonea Mining Plant, the dynamic analysis of the driving wheel (Koepe wheel was performed, by resistive electric tensometry methods, acceleration measurements, and vibromechanical analysis on the bearings of Koepe driving wheels, on functioning cycles and vibromechanical analysis of the reduction gear. The paper presents aspects regarding vibromechanical measurements and resistive electric tensometry methods in the winding machine..

  2. Performance of a 3 kW wind turbine generator with variable pitch control system

    International Nuclear Information System (INIS)

    Nagai, Baku M.; Ameku, Kazumasa; Roy, Jitendro Nath

    2009-01-01

    A prototype 3 kW horizontal upwind type wind turbine generator of 4 m in diameter has been designed and examined under real wind conditions. The machine was designed based on the concept that even small wind turbines should have a variable pitch control system just as large wind turbines, especially in Japan where typhoons occur at least once a year. A characteristic of the machine is the use of a worm and gear system with a stepping motor installed in the center of the hub, and the rotational main shaft. The machine is constructed with no mechanical breaking system so as to avoid damage from strong winds. In a storm, the wind turbine is slowed down by adjusting the pitch angle and the maximum electrical load. Usually the machine is controlled at several stages depending on the rotational speed of the blades. Two control methods have been applied: the variable pitch angle, and regulation of the generator field current. The characteristics of the generator under each rotational speed and field current are first investigated in the laboratory. This paper describes the performances of the wind turbine in terms of the functions of wind turbine rotational speed, generated outputs, and its stability for wind speed changes. The expected performances of the machine have been confirmed under real wind conditions and compared with numerical simulation results. The wind turbine showed a power coefficient of 0.257 under the average wind speed of 7.3 m/s.

  3. Topology Optimization of a High-Temperature Superconducting Field Winding of a Synchronous Machine

    DEFF Research Database (Denmark)

    Pozzi, Matias; Mijatovic, Nenad; Jensen, Bogi Bech

    2013-01-01

    This paper presents topology optimization (TO) of the high-temperature superconductor (HTS) field winding of an HTS synchronous machine. The TO problem is defined in order to find the minimum HTS material usage for a given HTS synchronous machine design. Optimization is performed using a modified...... genetic algorithm with local optimization search based on on/off sensitivity analysis. The results show an optimal HTS coil distribution, achieving compact designs with a maximum of approximately 22% of the available space for the field winding occupied with HTS tape. In addition, this paper describes...... potential HTS savings, which could be achieved using multiple power supplies for the excitation of the machine. Using the TO approach combined with two excitation currents, an additional HTS saving of 9.1% can be achieved....

  4. Variable cross-section windings for efficiency improvement of electric machines

    Science.gov (United States)

    Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

    2018-02-01

    Implementation of energy-saving technologies in industry is impossible without efficiency improvement of electric machines. The article considers the ways of efficiency improvement and mass and dimensions reduction of electric machines with electronic control. Features of compact winding design for stators and armatures are described. Influence of compact winding on thermal and electrical process is given. Finite element method was used in computer simulation.

  5. Multi-winding homopolar electric machine

    Science.gov (United States)

    Van Neste, Charles W

    2012-10-16

    A multi-winding homopolar electric machine and method for converting between mechanical energy and electrical energy. The electric machine includes a shaft defining an axis of rotation, first and second magnets, a shielding portion, and a conductor. First and second magnets are coaxial with the shaft and include a charged pole surface and an oppositely charged pole surface, the charged pole surfaces facing one another to form a repulsive field therebetween. The shield portion extends between the magnets to confine at least a portion of the repulsive field to between the first and second magnets. The conductor extends between first and second end contacts and is toroidally coiled about the first and second magnets and the shield portion to develop a voltage across the first and second end contacts in response to rotation of the electric machine about the axis of rotation.

  6. Superconducting Coil Winding Machine Control System

    Energy Technology Data Exchange (ETDEWEB)

    Nogiec, J. M. [Fermilab; Kotelnikov, S. [Fermilab; Makulski, A. [Fermilab; Walbridge, D. [Fermilab; Trombly-Freytag, K. [Fermilab

    2016-10-05

    The Spirex coil winding machine is used at Fermilab to build coils for superconducting magnets. Recently this ma-chine was equipped with a new control system, which al-lows operation from both a computer and a portable remote control unit. This control system is distributed between three layers, implemented on a PC, real-time target, and FPGA, providing respectively HMI, operational logic and direct controls. The system controls motion of all mechan-ical components and regulates the cable tension. Safety is ensured by a failsafe, redundant system.

  7. Wind Power Ramp Events Prediction with Hybrid Machine Learning Regression Techniques and Reanalysis Data

    Directory of Open Access Journals (Sweden)

    Laura Cornejo-Bueno

    2017-11-01

    Full Text Available Wind Power Ramp Events (WPREs are large fluctuations of wind power in a short time interval, which lead to strong, undesirable variations in the electric power produced by a wind farm. Its accurate prediction is important in the effort of efficiently integrating wind energy in the electric system, without affecting considerably its stability, robustness and resilience. In this paper, we tackle the problem of predicting WPREs by applying Machine Learning (ML regression techniques. Our approach consists of using variables from atmospheric reanalysis data as predictive inputs for the learning machine, which opens the possibility of hybridizing numerical-physical weather models with ML techniques for WPREs prediction in real systems. Specifically, we have explored the feasibility of a number of state-of-the-art ML regression techniques, such as support vector regression, artificial neural networks (multi-layer perceptrons and extreme learning machines and Gaussian processes to solve the problem. Furthermore, the ERA-Interim reanalysis from the European Center for Medium-Range Weather Forecasts is the one used in this paper because of its accuracy and high resolution (in both spatial and temporal domains. Aiming at validating the feasibility of our predicting approach, we have carried out an extensive experimental work using real data from three wind farms in Spain, discussing the performance of the different ML regression tested in this wind power ramp event prediction problem.

  8. Permanent magnet machine with windings having strand transposition

    Science.gov (United States)

    Qu, Ronghai; Jansen, Patrick Lee

    2009-04-21

    This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.

  9. The general atomic strand winding machine

    International Nuclear Information System (INIS)

    Matt, P.

    1976-01-01

    In conjunction with the integrated development of their high temperature gas cooled reactors (HTGR), General Atomic of San Diego, USA, also developed a strand winding system for the horizontal prestressing of pressure vessels. The machine lay-out, its capabilities and the test program carried out in the laboratory and on a full scale pressure vessel model are described. (author)

  10. Fine tuning support vector machines for short-term wind speed forecasting

    International Nuclear Information System (INIS)

    Zhou Junyi; Shi Jing; Li Gong

    2011-01-01

    Research highlights: → A systematic approach to tuning SVM models for wind speed prediction is proposed. → Multiple kernel functions and a wide range of tuning parameters are evaluated, and optimal parameters for each kernel function are obtained. → It is found that the forecasting performance of SVM is closely related to the dynamic characteristics of wind speed. → Under the optimal combination of parameters, different kernels give comparable forecasting accuracy. -- Abstract: Accurate forecasting of wind speed is critical to the effective harvesting of wind energy and the integration of wind power into the existing electric power grid. Least-squares support vector machines (LS-SVM), a powerful technique that is widely applied in a variety of classification and function estimation problems, carries great potential for the application of short-term wind speed forecasting. In this case, tuning the model parameters for optimal forecasting accuracy is a fundamental issue. This paper, for the first time, presents a systematic study on fine tuning of LS-SVM model parameters for one-step ahead wind speed forecasting. Three SVM kernels, namely linear, Gaussian, and polynomial kernels, are implemented. The SVM parameters considered include the training sample size, SVM order, regularization parameter, and kernel parameters. The results show that (1) the performance of LS-SVM is closely related to the dynamic characteristics of wind speed; (2) all parameters investigated greatly affect the performance of LS-SVM models; (3) under the optimal combination of parameters after fine tuning, the three kernels give comparable forecasting accuracy; (4) the performance of linear kernel is worse than the other two kernels when the training sample size or SVM order is small. In addition, LS-SVMs are compared against the persistence approach, and it is found that they can outperform the persistence model in the majority of cases.

  11. Machine for winding under tension a prestressing wire

    International Nuclear Information System (INIS)

    Perez, M.A.; Thillet, Georges.

    1975-01-01

    This invention concerns a machine for winding under tension a prestressing wire or cable. It is used in the wrapping of cylindrical structures, particularly concrete vessels, for the purpose of achieving radial prestressing in them [fr

  12. Design of large permanent magnetized synchronous electric machines: Low speed, high torque machines - generator for direct driven wind turbine - motor for rim driven thruster

    Energy Technology Data Exchange (ETDEWEB)

    Kroevel, Oeystein

    2011-02-15

    This work presents the design of two prototype permanent magnetized electric machines for two different applications where large permanent magnet machines might be used. Existing technology have been used as the fundament for new design and adapted to new applications, contributing, hopefully, to the development of better and more environmental friendly energy conversion. The first application presented is represented with a prototype made in cooperation with the industry in which a PM-motor is integrated into a propeller unit. Both because of the industrial connection, and the integration between the PM-motor and the propeller, the choices made for the PM-motor are conservative trying to reduce the risk. The direct rim driven thruster prototype includes a surface mounted radial flux permanent magnet machine (SM RFPM) with fractional slot winding with a q around 1. Other engineering features were introduced to make the integration of propeller and motor feasible, but without the PM-machine the thruster would not have reached the performance demand. An important part of the project was to show that the SM RFPM enables this solution, providing high performance with a large air gap. The prototype has been tested in sea, under harsh conditions, and even though the magnets have been exposed directly to sea water and been visible corroded, the electric motor still performs well within the specifications. The second application is represented with a prototype PM-generator for wind turbines. This is an example of a new, very low speed high torque machine. The generator is built to test phenomena regarding concentrated coils, and as opposed to the first application, being a pure academic university project, its success is not connected to its performance, but with the prototype's ability to expose the phenomena in question. The prototype, or laboratory model, of the generator for direct driven wind turbines features SM RFPM with concentrated coils (CC). An opportunity

  13. Device for delivering cryogen to rotary super-conducting winding of cryogen-cooled electrical machine

    International Nuclear Information System (INIS)

    Filippov, I.F.; Gorbunov, G.S.; Khutoretsky, G.M.; Popov, J.S.; Skachkov, J.V.; Vinokurov, A.A.

    1980-01-01

    A device is disclosed for delivering cryogen to a superconducting winding of a cryogen-cooled electrical machine comprising a pipe articulated along the axis of the electrical machine and intended to deliver cryogen. One end of said pipe is located in a rotary chamber which communicates through channels with the space of the electrical machine, and said space accommodating its superconducting winding. The said chamber accommodates a needle installed along the chamber axis, and the length of said needle is of sufficient length such that in the advanced position of said cryogen delivering pipe said needle reaches the end of the pipe. The layout of the electrical machine increases the reliability and effectiveness of the device for delivering cryogen to the superconducting winding, simplifies the design of the device and raises the efficiency of the electrical machine

  14. Winding machine and tools for the ISR Superconducting Quadrupole Prototype

    CERN Multimedia

    1975-01-01

    The picture shows the rotating and rocking winding machine with its "light" clamping system to keep the conductor turns in place during winding.At the back left one sees the conductor spool with its electromagnetic brake and the "heavy" clamping system used during curing. See also 7510217X, 7702690X.

  15. Analysis of induction machines with combined stator windings

    Czech Academy of Sciences Publication Activity Database

    Schreier, Luděk; Bendl, Jiří; Chomát, Miroslav

    2015-01-01

    Roč. 60, č. 2 (2015), s. 155-171 ISSN 0001-7043 R&D Projects: GA ČR GA13-35370S Institutional support: RVO:61388998 Keywords : induction machines * symmetrical components * combined stator winding Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  16. Stator for a rotating electrical machine having multiple control windings

    Science.gov (United States)

    Shah, Manoj R.; Lewandowski, Chad R.

    2001-07-17

    A rotating electric machine is provided which includes multiple independent control windings for compensating for rotor imbalances and for levitating/centering the rotor. The multiple independent control windings are placed at different axial locations along the rotor to oppose forces created by imbalances at different axial locations along the rotor. The multiple control windings can also be used to levitate/center the rotor with a relatively small magnetic field per unit area since the rotor and/or the main power winding provides the bias field.

  17. Fault diagnosis of direct-drive wind turbine based on support vector machine

    International Nuclear Information System (INIS)

    An, X L; Jiang, D X; Li, S H; Chen, J

    2011-01-01

    A fault diagnosis method of direct-drive wind turbine based on support vector machine (SVM) and feature selection is presented. The time-domain feature parameters of main shaft vibration signal in the horizontal and vertical directions are considered in the method. Firstly, in laboratory scale five experiments of direct-drive wind turbine with normal condition, wind wheel mass imbalance fault, wind wheel aerodynamic imbalance fault, yaw fault and blade airfoil change fault are carried out. The features of five experiments are analyzed. Secondly, the sensitive time-domain feature parameters in the horizontal and vertical directions of vibration signal in the five conditions are selected and used as feature samples. By training, the mapping relation between feature parameters and fault types are established in SVM model. Finally, the performance of the proposed method is verified through experimental data. The results show that the proposed method is effective in identifying the fault of wind turbine. It has good classification ability and robustness to diagnose the fault of direct-drive wind turbine.

  18. Design of an Electric Commutated Frog-Leg Winding Permanent-Magnet DC Machine

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    2014-03-01

    Full Text Available An electric commutated frog-leg winding permanent-magnet (PM DC machine is proposed in this paper. It has a semi-closed slotted stator with a classical type of mesh winding introduced from the conventional brushed DC machine and a polyphase electric commutation besides a PM excitation rotor and a circular arrayed Hall position sensor. Under the cooperation between the position sensor and the electric commutation, the proposed machine is basically operated on the same principle of the brushed one. Because of its simplex frog-leg winding, the combination between poles and slots is designed as 4/22, and the number of phases is set as 11. By applying an exact analytical method, which is verified comparable with the finite element analyses (FEA, to the prediction of its instantaneous magnetic field, electromotive force (EMF, cogging torque and output torque, it is well designed with a series of parameters in dimension aiming at the lowest cogging torque. A 230 W, 4-pole, and 22-slot new machine is prototyped and tested to verify the analysis.

  19. Technological and economical analysis of salient pole and permanent magnet synchronous machines designed for wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Guendogdu, Tayfun, E-mail: tgundogdu@itu.edu.tr [Istanbul Technical University, Department of Electrical Engineering, Ayazaga Campus, 34469 Maslak/Istanbul (Turkey); Koemuergoez, Gueven, E-mail: komurgoz@itu.edu.tr [Istanbul Technical University, Department of Electrical Engineering, Ayazaga Campus, 34469 Maslak/Istanbul (Turkey)

    2012-08-15

    Chinese export restrictions already reduced the planning reliability for investments in permanent magnet wind turbines. Today the production of permanent magnets consumes the largest proportion of rare earth elements, with 40% of the rare earth-based magnets used for generators and other electrical machines. The cost and availability of NdFeB magnets will likely determine the production rate of permanent magnet generators. The high volatility of rare earth metals makes it very difficult to quote a price. Prices may also vary from supplier to supplier to an extent of up to 50% for the same size, shape and quantity with a minor difference in quality. The paper presents the analysis and the comparison of salient pole with field winding and of peripheral winding synchronous electrical machines, presenting important advantages. A neodymium alloy magnet rotor structure has been considered and compared to the salient rotor case. The Salient Pole Synchronous Machine and the Permanent Magnet Synchronous Machine were designed so that the plate values remain constant. The Eddy current effect on the windings is taken into account during the design, and the efficiency, output power and the air-gap flux density obtained after the simulation were compared. The analysis results clearly indicate that Salient Pole Synchronous Machine designs would be attractive to wind power companies. Furthermore, the importance of the design of electrical machines and the determination of criteria are emphasized. This paper will be a helpful resource in terms of examination and comparison of the basic structure and magnetic features of the Salient Pole Synchronous Machine and Permanent Magnet Synchronous Machine. Furthermore, an economic analysis of the designed machines was conducted. - Highlights: Black-Right-Pointing-Pointer Importance of the design of electrical machines and the determination of criteria are emphasized. Black-Right-Pointing-Pointer Machines were investigated in terms of

  20. Technological and economical analysis of salient pole and permanent magnet synchronous machines designed for wind turbines

    International Nuclear Information System (INIS)

    Gündoğdu, Tayfun; Kömürgöz, Güven

    2012-01-01

    Chinese export restrictions already reduced the planning reliability for investments in permanent magnet wind turbines. Today the production of permanent magnets consumes the largest proportion of rare earth elements, with 40% of the rare earth-based magnets used for generators and other electrical machines. The cost and availability of NdFeB magnets will likely determine the production rate of permanent magnet generators. The high volatility of rare earth metals makes it very difficult to quote a price. Prices may also vary from supplier to supplier to an extent of up to 50% for the same size, shape and quantity with a minor difference in quality. The paper presents the analysis and the comparison of salient pole with field winding and of peripheral winding synchronous electrical machines, presenting important advantages. A neodymium alloy magnet rotor structure has been considered and compared to the salient rotor case. The Salient Pole Synchronous Machine and the Permanent Magnet Synchronous Machine were designed so that the plate values remain constant. The Eddy current effect on the windings is taken into account during the design, and the efficiency, output power and the air-gap flux density obtained after the simulation were compared. The analysis results clearly indicate that Salient Pole Synchronous Machine designs would be attractive to wind power companies. Furthermore, the importance of the design of electrical machines and the determination of criteria are emphasized. This paper will be a helpful resource in terms of examination and comparison of the basic structure and magnetic features of the Salient Pole Synchronous Machine and Permanent Magnet Synchronous Machine. Furthermore, an economic analysis of the designed machines was conducted. - Highlights: ► Importance of the design of electrical machines and the determination of criteria are emphasized. ► Machines were investigated in terms of efficiency, weight and maintenance requirements. ► An

  1. Accounting for the speed shear in wind turbine power performance measurement

    DEFF Research Database (Denmark)

    Wagner, Rozenn

    the vertical wind shear and the turbulence intensity. The work presented in this thesis consists of the description and the investigation of a simple method to account for the wind speed shear in the power performance measurement. Ignoring this effect was shown to result in a power curve dependant on the shear...... for turbulence intensity suggested by Albers. The second method was found to be more suitable for normalising the power curve for the turbulence intensity. Using the equivalent wind speed accounting for the wind shear in the power performance measurement was shown to result in a more repeatable power curve than......The power curve of a wind turbine is the primary characteristic of the machine as it is the basis of the warranty for it power production. The current IEC standard for power performance measurement only requires the measurement of the wind speed at hub height and the air density to characterise...

  2. Estimation of the wind turbine yaw error by support vector machines

    DEFF Research Database (Denmark)

    Sheibat-Othman, Nida; Othman, Sami; Tayari, Raoaa

    2015-01-01

    Wind turbine yaw error information is of high importance in controlling wind turbine power and structural load. Normally used wind vanes are imprecise. In this work, the estimation of yaw error in wind turbines is studied using support vector machines for regression (SVR). As the methodology...... is data-based, simulated data from a high fidelity aero-elastic model is used for learning. The model simulates a variable speed horizontal-axis wind turbine composed of three blades and a full converter. Both partial load (blade angles fixed at 0 deg) and full load zones (active pitch actuators...

  3. Application of rare-earth magnets in high-performance electric machines

    International Nuclear Information System (INIS)

    Ramsden, V.S.

    1998-01-01

    Some state of the art developments of high-performance machines using rare-earth magnets are reviewed with particular examples drawn from a number of novel machine designs developed jointly by the Faculty of Engineering, University of Technology, Sydney (UTS) and CSIRO Telecommunications and Industrial Physics. These designs include an 1800 W, 1060 rev/min, 98% efficient solar car in-wheel motor using a Halbach magnet array, axial flux, and ironless winding; a 1200 W, 3000 rev/min, 91% efficient solar-powered, water-filled, submersible, bore-hole pump motor using a surface magnet rotor; a 500 W, 10000 rev/min, 87% efficient, oil-filled, oil-well tractor motor using a 2-pole cylindrical magnet rotor and slotless winding; a 75 kW, 48000 rev/min, 97% efficient, high-speed compressor drive with 2-pole cylindrical magnet rotor, slotted stator, and refrigerant cooling; and a 20 kW, 211 rev/min, 87% efficient, direct-drive generator for wind turbines with very low starting torque using an outer rotor with surface magnets and a slotted stator. (orig.)

  4. Direct Drive Synchronous Machine Models for Stability Assessment of Wind Farms

    Energy Technology Data Exchange (ETDEWEB)

    Poeller, Markus; Achilles, Sebastian [DIgSILENT GmbH, Gomaringen (Germany)

    2003-11-01

    The increasing size of wind farms requires power system stability analysis including dynamic wind generator models. For turbines above 1MW doubly-fed induction machines are the most widely used concept. However, especially in Germany, direct-drive wind generators based on converter-driven synchronous generator concepts have reached considerable market penetration. This paper presents converter driven synchronous generator models of various order that can be used for simulating transients and dynamics in a very wide time range.

  5. A novel design of DC-AC electrical machine rotary converter for hybrid solar and wind energy applications

    International Nuclear Information System (INIS)

    Mohammed, K G; Ramli, A Q; Amirulddin, U A U

    2013-01-01

    This paper proposes the design of a new bi-directional DC-AC rotary converter machine to convert a d.c. voltage to three-phase voltage and vice-versa using a two-stage energy conversion machine. The rotary converter consists of two main stages which are combined into single frame. These two stages are constructed from three main electromagnetic components. The first inner electromagnetic component represents the input stage that enables the DC power generated by solar energy from photo-voltaic cells to be transformed by the second and third components electro-magnetically to produce multi-phase voltages at the output stage. At the same time, extra kinetic energy from wind, which is sufficiently available, can be added to existing torque on the second electromagnetic component. Both of these input energies will add up to the final energy generated at the output terminals. Therefore, the machine will be able to convert solar and wind energies to the output terminals simultaneously. If the solar energy is low, the available wind energy will be able to provide energy to the output terminals and at the same time charges the batteries which are connected as backup system. At this moment, the machine behaves as wind turbine. The energy output from the machine benefits from two energy sources which are solar and wind. At night when the solar energy is not available and also the load is low, the wind energy is able to charge the batteries and at the same time provides output electrical power to the remaining the load. Therefore, the proposed system will have high usage of available renewable energy as compared to separated wind or solar systems. MATLAB codes are used to calculate the required dimensions, the magnetic and electrical circuits parameters to design of the new bi-directional rotary converter machine.

  6. Dynamic modeling and performance evaluation of axial flux PMSG based wind turbine system with MPPT control

    Directory of Open Access Journals (Sweden)

    Vahid Behjat

    2014-12-01

    Full Text Available This research work develops dynamic model of a gearless small scale wind power generation system based on a direct driven single sided outer rotor AFPMSG with coreless armature winding. Dynamic modeling of the AFPMSG based wind turbine requires machine parameters. To this end, a 3D FEM model of the generator is developed and from magnetostatic and transient analysis of the FEM model, machine parameters are calculated and utilized in dynamic modeling of the system. A maximum power point tracking (MPPT-based FOC control approach is used to obtain maximum power from the variable wind speed. The simulation results show the proper performance of the developed dynamic model of the AFPMSG, control approach and power generation system.

  7. Feature selection in wind speed prediction systems based on a hybrid coral reefs optimization – Extreme learning machine approach

    International Nuclear Information System (INIS)

    Salcedo-Sanz, S.; Pastor-Sánchez, A.; Prieto, L.; Blanco-Aguilera, A.; García-Herrera, R.

    2014-01-01

    Highlights: • A novel approach for short-term wind speed prediction is presented. • The system is formed by a coral reefs optimization algorithm and an extreme learning machine. • Feature selection is carried out with the CRO to improve the ELM performance. • The method is tested in real wind farm data in USA, for the period 2007–2008. - Abstract: This paper presents a novel approach for short-term wind speed prediction based on a Coral Reefs Optimization algorithm (CRO) and an Extreme Learning Machine (ELM), using meteorological predictive variables from a physical model (the Weather Research and Forecast model, WRF). The approach is based on a Feature Selection Problem (FSP) carried out with the CRO, that must obtain a reduced number of predictive variables out of the total available from the WRF. This set of features will be the input of an ELM, that finally provides the wind speed prediction. The CRO is a novel bio-inspired approach, based on the simulation of reef formation and coral reproduction, able to obtain excellent results in optimization problems. On the other hand, the ELM is a new paradigm in neural networks’ training, that provides a robust and extremely fast training of the network. Together, these algorithms are able to successfully solve this problem of feature selection in short-term wind speed prediction. Experiments in a real wind farm in the USA show the excellent performance of the CRO–ELM approach in this FSP wind speed prediction problem

  8. Performance of a Folded-Strip Toroidally Wound Induction Machine

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Jack, Alan G.; Atkinson, Glynn J.

    2011-01-01

    This paper presents the measured experimental results from a four-pole toroidally wound induction machine, where the stator is constructed as a pre-wound foldable strip. It shows that if the machine is axially restricted in length, the toroidally wound induction machine can have substantially...... shorter stator end-windings than conventionally wound induction machines, and hence that a toroidally wound induction machine can have lower losses and a higher efficiency. The paper also presents the employed construction method, which emphasizes manufacturability, and highlights the advantages...

  9. Winding machines for the manufacturing of superconductive coils of the main European fusion research machines

    CERN Document Server

    Cazzaniga, R; D’Urzo, C

    2005-01-01

    The successfull construction of large magnets passes through the development and application of non-conventional manufacturing processes. A difficult and delicate step in the manufacturing of superconducting coils is the conductor winding technique. It is often a challenging and technologically advanced process, developed according to the requirements of each project. An important aspect during the winding is to avoid any deformation of the cable cross section leading to a damage of the strands and to maintain the design features of the cable. A second aspect is to assure the suitable repeatability and a production rate for an industrial process. The winding line is a system of different machines linked and tuned together properly designed for each project. An adapted software assures the overall process control. TPA realized for ANSALDO Superconduttori the winding lines for many projects: TFMC (NET-TEAM), CMS (INFN-CERN), WENDELSTEIN W7-X (Max Planck Institute, IPP), etc. The experience acquired in this fiel...

  10. Filament winding technique, experiment and simulation analysis on tubular structure

    Science.gov (United States)

    Quanjin, Ma; Rejab, M. R. M.; Kaige, Jiang; Idris, M. S.; Harith, M. N.

    2018-04-01

    Filament winding process has emerged as one of the potential composite fabrication processes with lower costs. Filament wound products involve classic axisymmetric parts (pipes, rings, driveshafts, high-pressure vessels and storage tanks), non-axisymmetric parts (prismatic nonround sections and pipe fittings). Based on the 3-axis filament winding machine has been designed with the inexpensive control system, it is completely necessary to make a relative comparison between experiment and simulation on tubular structure. In this technical paper, the aim of this paper is to perform a dry winding experiment using the 3-axis filament winding machine and simulate winding process on the tubular structure using CADWIND software with 30°, 45°, 60° winding angle. The main result indicates that the 3-axis filament winding machine can produce tubular structure with high winding pattern performance with different winding angle. This developed 3-axis winding machine still has weakness compared to CAWIND software simulation results with high axes winding machine about winding pattern, turnaround impact, process error, thickness, friction impact etc. In conclusion, the 3-axis filament winding machine improvements and recommendations come up with its comparison results, which can intuitively understand its limitations and characteristics.

  11. An effective secondary decomposition approach for wind power forecasting using extreme learning machine trained by crisscross optimization

    International Nuclear Information System (INIS)

    Yin, Hao; Dong, Zhen; Chen, Yunlong; Ge, Jiafei; Lai, Loi Lei; Vaccaro, Alfredo; Meng, Anbo

    2017-01-01

    Highlights: • A secondary decomposition approach is applied in the data pre-processing. • The empirical mode decomposition is used to decompose the original time series. • IMF1 continues to be decomposed by applying wavelet packet decomposition. • Crisscross optimization algorithm is applied to train extreme learning machine. • The proposed SHD-CSO-ELM outperforms other pervious methods in the literature. - Abstract: Large-scale integration of wind energy into electric grid is restricted by its inherent intermittence and volatility. So the increased utilization of wind power necessitates its accurate prediction. The contribution of this study is to develop a new hybrid forecasting model for the short-term wind power prediction by using a secondary hybrid decomposition approach. In the data pre-processing phase, the empirical mode decomposition is used to decompose the original time series into several intrinsic mode functions (IMFs). A unique feature is that the generated IMF1 continues to be decomposed into appropriate and detailed components by applying wavelet packet decomposition. In the training phase, all the transformed sub-series are forecasted with extreme learning machine trained by our recently developed crisscross optimization algorithm (CSO). The final predicted values are obtained from aggregation. The results show that: (a) The performance of empirical mode decomposition can be significantly improved with its IMF1 decomposed by wavelet packet decomposition. (b) The CSO algorithm has satisfactory performance in addressing the premature convergence problem when applied to optimize extreme learning machine. (c) The proposed approach has great advantage over other previous hybrid models in terms of prediction accuracy.

  12. Armature reaction effects on HTS field winding in HTS machine

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech

    2013-01-01

    sensitivity to both armature reaction intensity and angular position with respect to the HTS coils. Furthermore, the characterization of the HTS feld winding has been correlated to the electromagnetic torque of the machine where the maximal Ic reduction of 21% has been observed for the maximum torque....

  13. Generation and Validation of Spatial Distribution of Hourly Wind Speed Time-Series using Machine Learning

    International Nuclear Information System (INIS)

    Veronesi, F; Grassi, S

    2016-01-01

    Wind resource assessment is a key aspect of wind farm planning since it allows to estimate the long term electricity production. Moreover, wind speed time-series at high resolution are helpful to estimate the temporal changes of the electricity generation and indispensable to design stand-alone systems, which are affected by the mismatch of supply and demand. In this work, we present a new generalized statistical methodology to generate the spatial distribution of wind speed time-series, using Switzerland as a case study. This research is based upon a machine learning model and demonstrates that statistical wind resource assessment can successfully be used for estimating wind speed time-series. In fact, this method is able to obtain reliable wind speed estimates and propagate all the sources of uncertainty (from the measurements to the mapping process) in an efficient way, i.e. minimizing computational time and load. This allows not only an accurate estimation, but the creation of precise confidence intervals to map the stochasticity of the wind resource for a particular site. The validation shows that machine learning can minimize the bias of the wind speed hourly estimates. Moreover, for each mapped location this method delivers not only the mean wind speed, but also its confidence interval, which are crucial data for planners. (paper)

  14. Generation and Validation of Spatial Distribution of Hourly Wind Speed Time-Series using Machine Learning

    Science.gov (United States)

    Veronesi, F.; Grassi, S.

    2016-09-01

    Wind resource assessment is a key aspect of wind farm planning since it allows to estimate the long term electricity production. Moreover, wind speed time-series at high resolution are helpful to estimate the temporal changes of the electricity generation and indispensable to design stand-alone systems, which are affected by the mismatch of supply and demand. In this work, we present a new generalized statistical methodology to generate the spatial distribution of wind speed time-series, using Switzerland as a case study. This research is based upon a machine learning model and demonstrates that statistical wind resource assessment can successfully be used for estimating wind speed time-series. In fact, this method is able to obtain reliable wind speed estimates and propagate all the sources of uncertainty (from the measurements to the mapping process) in an efficient way, i.e. minimizing computational time and load. This allows not only an accurate estimation, but the creation of precise confidence intervals to map the stochasticity of the wind resource for a particular site. The validation shows that machine learning can minimize the bias of the wind speed hourly estimates. Moreover, for each mapped location this method delivers not only the mean wind speed, but also its confidence interval, which are crucial data for planners.

  15. Numeric-modeling sensitivity analysis of the performance of wind turbine arrays

    Energy Technology Data Exchange (ETDEWEB)

    Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

    1982-06-01

    An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

  16. DIAGNOSIS OF THE WINDING MACHINE IN THE OLD SHAFT WITH SKIP IN LONEA MINING PLANT

    OpenAIRE

    Răzvan Bogdan ITU; Vilhelm ITU

    2017-01-01

    To study the operation of the winding machine in the Old Shaft with Skip in Lonea Mining Plant, the dynamic analysis of the driving wheel (Koepe wheel) was performed, by resistive electric tensometry methods, acceleration measurements, and vibromechanical analysis on the bearings of Koepe driving wheels, on functioning cycles and vibromechanical analysis of the reduction gear. The paper presents aspects regarding vibromechanical measurements and resistive electric tensometry me...

  17. Two Machine Learning Approaches for Short-Term Wind Speed Time-Series Prediction.

    Science.gov (United States)

    Ak, Ronay; Fink, Olga; Zio, Enrico

    2016-08-01

    The increasing liberalization of European electricity markets, the growing proportion of intermittent renewable energy being fed into the energy grids, and also new challenges in the patterns of energy consumption (such as electric mobility) require flexible and intelligent power grids capable of providing efficient, reliable, economical, and sustainable energy production and distribution. From the supplier side, particularly, the integration of renewable energy sources (e.g., wind and solar) into the grid imposes an engineering and economic challenge because of the limited ability to control and dispatch these energy sources due to their intermittent characteristics. Time-series prediction of wind speed for wind power production is a particularly important and challenging task, wherein prediction intervals (PIs) are preferable results of the prediction, rather than point estimates, because they provide information on the confidence in the prediction. In this paper, two different machine learning approaches to assess PIs of time-series predictions are considered and compared: 1) multilayer perceptron neural networks trained with a multiobjective genetic algorithm and 2) extreme learning machines combined with the nearest neighbors approach. The proposed approaches are applied for short-term wind speed prediction from a real data set of hourly wind speed measurements for the region of Regina in Saskatchewan, Canada. Both approaches demonstrate good prediction precision and provide complementary advantages with respect to different evaluation criteria.

  18. Comparative study of the behavior of wind-turbines in a wind farm

    Energy Technology Data Exchange (ETDEWEB)

    Migoya, Emilio; Crespo, Antonio; Garcia, Javier; Manuel, Fernando; Jimenez, Angel [Universidad Politecnica de Madrid (UPM), Madrid (Spain). Departamento de Ingenieria Energetica y Fluidomecanica, Laboratorio de Mecanica de Fluidos; Moreno, Fermin [Comision Nacional de la Energia, Madrid (Spain); Costa, Alexandre [Energia Eolica, Division de Energias Renovables, CIEMAT, Madrid (Spain)

    2007-10-15

    The Sotavento wind farm is an experimental wind farm which has different types of wind turbines. It is located in an area whose topography is moderately complex, and where wake effects can be significant. One of the objectives of Sotavento wind farm is to compare the performances of the different machines; particularly regarding power production, maintenance and failures. However, because of wakes and topography, the different machines are not working under identical conditions. Two linearized codes have been used to estimate topography effects: UPMORO and WAsP. For wind directions in which topography is abrupt, the non-linear flow equations have been solved with the commercial code FLUENT, although the results are only qualitatively used. For wake effects, the UPMPARK code has been applied. As a result, the incident velocity over each wind turbine is obtained, and the power production is estimated by means of the power curve of each machine. Experimental measurements give simultaneously the wind characteristics at the measuring stations, the wind velocity, at the nacelle anemometer, and the power production of each wind turbine. These experimental results are employed to validate the numerical predictions. The main objective of this work is to deduce and validate a relationship between the wind characteristics measured in the anemometers and the wind velocity and the power output in each machine. (author)

  19. Wind generator based on cascade connection of two asynchronized synchronous machines

    International Nuclear Information System (INIS)

    Dzhagarov, N.; Dzhagarova, Yu.

    2000-01-01

    A model of a wind generator with two asynchronized synchronous machines presented and different regimes are investigated. The analysis shows that the suggested scheme of a brushless generator works and has more advantages (reliability, easy for operation) in comparison with the known ones

  20. High speed operation of permanent magnet machines

    Science.gov (United States)

    El-Refaie, Ayman M.

    This work proposes methods to extend the high-speed operating capabilities of both the interior PM (IPM) and surface PM (SPM) machines. For interior PM machines, this research has developed and presented the first thorough analysis of how a new bi-state magnetic material can be usefully applied to the design of IPM machines. Key elements of this contribution include identifying how the unique properties of the bi-state magnetic material can be applied most effectively in the rotor design of an IPM machine by "unmagnetizing" the magnet cavity center posts rather than the outer bridges. The importance of elevated rotor speed in making the best use of the bi-state magnetic material while recognizing its limitations has been identified. For surface PM machines, this research has provided, for the first time, a clear explanation of how fractional-slot concentrated windings can be applied to SPM machines in order to achieve the necessary conditions for optimal flux weakening. A closed-form analytical procedure for analyzing SPM machines designed with concentrated windings has been developed. Guidelines for designing SPM machines using concentrated windings in order to achieve optimum flux weakening are provided. Analytical and numerical finite element analysis (FEA) results have provided promising evidence of the scalability of the concentrated winding technique with respect to the number of poles, machine aspect ratio, and output power rating. Useful comparisons between the predicted performance characteristics of SPM machines equipped with concentrated windings and both SPM and IPM machines designed with distributed windings are included. Analytical techniques have been used to evaluate the impact of the high pole number on various converter performance metrics. Both analytical techniques and FEA have been used for evaluating the eddy-current losses in the surface magnets due to the stator winding subharmonics. Techniques for reducing these losses have been

  1. Effect of pole number and slot number on performance of dual rotor permanent magnet wind power generator using ferrite magnets

    Directory of Open Access Journals (Sweden)

    Peifeng Xu

    2017-05-01

    Full Text Available Dual rotor permanent magnet (DRPM wind power generator using ferrite magnets has the advantages of low cost, high efficiency, and high torque density. How to further improve the performance and reduce the cost of the machine by proper choice of pole number and slot number is an important problem to be solved when performing preliminarily design a DRPM wind generator. This paper presents a comprehensive performance comparison of a DRPM wind generator using ferrite magnets with different slot and pole number combinations. The main winding factors are calculated by means of the star of slots. Under the same machine volume and ferrite consumption, the flux linkage, back-electromotive force (EMF, cogging torque, output torque, torque pulsation, and losses are investigated and compared using finite element analysis (FEA. The results show that the slot and pole number combinations have an important impact on the generator properties.

  2. Two Capacitive Micro-Machined Ultrasonic Transducers for Wind Speed Measurement.

    Science.gov (United States)

    Bui, Gia Thinh; Jiang, Yu-Tsung; Pang, Da-Chen

    2016-06-02

    This paper presents a new wind speed measurement method using a single capacitive micro-machined ultrasonic transducer (CMUT). The CMUT was arranged perpendicular to the direction of the wind flow, and a reflector was set up a short distance away, facing the CMUT. To reduce the size, weight, cost, and power consumption of conventional ultrasonic anemometers this study proposes two CMUT designs for the measurement of wind speed using either the amplitude of the signal or the time of flight (TOF). Each CMUT with a double array element design can transmit and receive signals in five different operation modes. Experiments showed that the two CMUT designs utilizing the TOF were better than those utilizing the amplitude of the signal for wind speed measurements ranging from 1 m/s to 10 m/s, providing a measurement error of less than 0.2 m/s. These results indicate that the sensitivity of the TOF is independent of the five operation modes.

  3. THE VERIFICATION BRAKE MECHANISM OF WINDING MACHINES WITH SINGLE CABLE DRIVING WHEELS ON

    Directory of Open Access Journals (Sweden)

    Răzvan Bogdan ITU

    2017-12-01

    Full Text Available The development in safe conditions of the extracting process continuously imposes the need of optimal functioning of the extracting installations as important links in the transport flow. Diagnosis of winding engine brake mechanism in mines is important to provide normal extraction vessel movement in the shaft, or stopping machines in a certain position of the vessels in disturbances or failures. The paper presents the calculus of safety coefficients in the use of safety and maneuver brakes. Mine winding engines brake mechanisms is important to provide normal extraction vessel movement along the shaft, or stopping the engine in a certain position of the vessel in disturbances or failures. To assess the real safety coefficient, results obtained by tensiometric measurements were used. After diagnosis, necessary information is obtained to improve present maintenance system and repair this category of machines in view of increasing safety in use of winding installations, with possibility of monitoring brake mechanism...

  4. Winding machines for the manufacturing of superconductive coils of the main European fusion research machines

    International Nuclear Information System (INIS)

    Cazzaniga, Rodolfo; Valle, N.; D'Urzo, C.

    2005-01-01

    The successful construction of large magnets passes through the development and application of non-conventional manufacturing processes. A difficult and delicate step in the manufacturing of superconducting coils is the conductor winding technique. It is often a challenging and technologically advanced process, developed according to the requirements of each project. An important aspect during the winding is to avoid any deformation of the cable cross section leading to a damage of the strands and to maintain the design features of the cable. A second aspect is to assure the suitable repeatability and a production rate for an industrial process. The winding line is a system of different machines linked and tuned together properly designed for each project. An adapted software assures the overall process control. TPA realized for ANSALDO Superconduttori the winding lines for many projects: TFMC (NET-TEAM), CMS (INFN-CERN), WENDELSTEIN W7-X (Max Planck Institute, IPP), etc. The experience acquired in this field by ANSALDO Superconduttori and by TPA (as manufacturing tools and equipments supplier) has been acknowledged by CERN with 'The CMS Gold Award' of the Year 2004. The paper describes the main features of the winding lines, the main problems, the technical solutions used for the above mentioned projects and the new ideas for the forthcoming ones

  5. The measured field performances of eight different mechanical and air-lift water-pumping wind-turbines

    Energy Technology Data Exchange (ETDEWEB)

    Kentfield, J.A.C. [Univ. of Calgary, Alberta (Canada)

    1996-12-31

    Results are presented of the specific performances of eight, different, water-pumping wind-turbines subjected to impartial tests at the Alberta Renewable Energy Test Site (ARETS), Alberta, Canada. The results presented which were derived from the test data, obtained independently of the equipment manufacturers, are expressed per unit of rotor projected area to eliminate the influence of machine size. Hub-height wind speeds and water flow rates for a common lift of 5.5 m (18 ft) constitute the essential test data. A general finding was that, to a first approximation, there were no major differences in specific performance between four units equipped with conventional reciprocating pumps two of which employed reduction gearing and two of which did not. It was found that a unit equipped with a Moyno pump performed well but three air-lift machines had, as was expected, poorer specific performances than the more conventional equipment. 10 refs., 9 figs.

  6. 风速波动下变速机组风电场的单机等值建模方法%Single machine equivalent modeling method of wind farms with variable speed wind turbines under wind speed fluctuations

    Institute of Scientific and Technical Information of China (English)

    苏勋文; 秦浩宇; 杨荣峰; 岳红轩

    2017-01-01

    由于风电机组的输出功率滞后于风速波动,等值风计算不能反映实际工况,采用DIg-SILENT/Powerfactory搭建变速机组风电场详细模型和单机等值模型,研究风速波动下双馈机组和直驱永磁机组风电场模型的并网点输出特性.研究表明:对于双馈机组风电场,与详细模型相比,单机等值模型会出现一定误差;对于直驱永磁机组风电场,使用等值风的优于使用平均风的等值模型.利用单机表征法建立的风电场等值模型与详细模型的动态响应基本一致.该研究验证了单机等值方法的有效性和适用性.%This paper seeks to explore an efficient and simple wind farm equivalent modeling meth-od. The exploration involves the following process:providing the calculation method of the equivalent pa-rameters and equivalent wind in the single machine equivalent model; developing a detailed model of wind farm and a single machine equivalent model using the simulation software DIgSILENT/Powerfactory;investigating dynamic response at point of interconnection of wind farm with doubly fed induction genera-tor wind turbines and directly driven permanent magnet wind turbines under wind speed fluctuation. The results demonstrate that, in the case of wind farm with doubly fed induction generator wind turbines, where wind turbine operates at the output power lagging behind the wind speed fluctuation, equivalent wind calculation fails to reflect the actual operating conditions; there occurs a certain error in the single machine equivalent model compared;equivalent wind is better than the average wind for wind farm with directly driven permanent magnet wind turbines;and the dynamic response is basically same between the equivalent model of wind farm based on the single machine representation method and the detailed model of wind farm. The research verifies the validity and applicability of the single machine equivalent method.

  7. Machine performance assessment and enhancement for a hexapod machine

    Energy Technology Data Exchange (ETDEWEB)

    Mou, J.I. [Arizona State Univ., Tempe, AZ (United States); King, C. [Sandia National Labs., Livermore, CA (United States). Integrated Manufacturing Systems Center

    1998-03-19

    The focus of this study is to develop a sensor fused process modeling and control methodology to model, assess, and then enhance the performance of a hexapod machine for precision product realization. Deterministic modeling technique was used to derive models for machine performance assessment and enhancement. Sensor fusion methodology was adopted to identify the parameters of the derived models. Empirical models and computational algorithms were also derived and implemented to model, assess, and then enhance the machine performance. The developed sensor fusion algorithms can be implemented on a PC-based open architecture controller to receive information from various sensors, assess the status of the process, determine the proper action, and deliver the command to actuators for task execution. This will enhance a hexapod machine`s capability to produce workpieces within the imposed dimensional tolerances.

  8. Dynamoelectric machine with a superconductive field winding that can operate in either a synchronous or an asynchronous mode

    International Nuclear Information System (INIS)

    Mole, C.J.; Haller, H.E. III.

    1977-01-01

    Two parallel magnetic flux paths are provided in a dynamoelectric machine having a superconductive field winding. A first, or main, magnetic flux path includes at least one area of nonferromagnetic or diamagnetic material. A second, or shunt, magnetic flux path prevents the relatively low frequency ac flux present during starting or asynchronous operation of the machine, when used as an ac motor, from penetrating the superconductive winding

  9. Data mining techniques for performance analysis of onshore wind farms

    International Nuclear Information System (INIS)

    Astolfi, Davide; Castellani, Francesco; Garinei, Alberto; Terzi, Ludovico

    2015-01-01

    Highlights: • Indicators are formulated for monitoring quality of wind turbines performances. • State dynamics is processed for formulation of two Malfunctioning Indexes. • Power curve analysis is revisited. • A novel definition of polar efficiency is formulated and its consistency is checked. • Mechanical effects of wakes are analyzed as nacelle stationarity and misalignment. - Abstract: Wind turbines are an energy conversion system having a low density on the territory, and therefore needing accurate condition monitoring in the operative phase. Supervisory Control And Data Acquisition (SCADA) control systems have become ubiquitous in wind energy technology and they pose the challenge of extracting from them simple and explanatory information on goodness of operation and performance. In the present work, post processing methods are applied on the SCADA measurements of two onshore wind farms sited in southern Italy. Innovative and meaningful indicators of goodness of performance are formulated. The philosophy is a climax in the granularity of the analysis: first, Malfunctioning Indexes are proposed, which quantify goodness of merely operational behavior of the machine, irrespective of the quality of output. Subsequently the focus is shifted to the analysis of the farms in the productive phase: dependency of farm efficiency on wind direction is investigated through the polar plot, which is revisited in a novel way in order to make it consistent for onshore wind farms. Finally, the inability of the nacelle to optimally follow meandering wind due to wakes is analysed through a Stationarity Index and a Misalignment Index, which are shown to capture the relation between mechanical behavior of the turbine and degradation of the power output

  10. Performance evaluation of fractional-slot tubular permanent magnet machines with low space harmonics

    Directory of Open Access Journals (Sweden)

    Wang Jiabin

    2015-12-01

    Full Text Available This paper evaluates the perforamnce of fractional-slot per pole winding configurations for tubular permanent magnet (PM machines that can effectively eliminate the most undesirable space harmonics in a simple and cost-effective manner. The benefits of the proposed machine topology winding configurations are illustrated through comparison with 9-slot, 10-pole tubular PM machine developed for a free piston energy converter under the same specification and volumetric constraints. It has been shown that the proposed machine topology results in more than 7 times reduction in the eddy current loss in the mover magnets and supporting tube, and hence avoids potential problem of excessive mover temperature and risk of demagnetization.

  11. Kompensasi Kesalahan Sensor Berbasis Descriptor dengan Performa H_inf pada Winding Machine

    Directory of Open Access Journals (Sweden)

    Hendra Antomy

    2015-12-01

    Full Text Available Kesalahan pada sensor dapat terjadi pada sistem kontrol dengan umpan balik sehingga mengakibatkan sistem mengalami penurunan stabilitas dan performa. Fault Tolerant Control (FTC adalah metode untuk mengkompensasi kesalahan pada komponen sistem, salah satunya adalah kesalahan sensor. FTC dapat disusun dengan cara mendesain estimator untuk mengestimasi besarnya kesalahan sensor yang terjadi. Kompensasi dilakukan dengan cara mengurangkan estimasi kesalahan sensor dengan keluaran sistem. Pada makalah ini, FTC untuk kesalahan sensor diterapkan pada sistem winding machine. Estimator dirancang menggunakan pendekatan sistem descriptor dan didesain memenuhi performa H_inf. Permasalahan dalam desain estimator dirumuskan dalam bentuk Linear Matrix Inequality (LMI. Untuk merancang kontroler nominal, sistem winding machine direpresentasikan sebagai model fuzzy Takagi-Sugeno (T-S. Berdasarkan model tersebut, aturan kontroler disusun menggunakan konsep Parallel Distributed Compensation (PDC dengan struktur kontrol servo tipe 1. Hasil simulasi menunjukkan bahwa kompensasi yang diberikan dapat menjaga performa dan stabilitas sistem saat terjadi kesalahan sensor. Selain itu, estimator memenuhi performa H_inf dengan L2-Gain kurang dari tingkat pelemahan yang ditentukan.

  12. Efficient operation of anisotropic synchronous machines for wind energy systems

    International Nuclear Information System (INIS)

    Eldeeb, Hisham; Hackl, Christoph M.; Kullick, Julian

    2016-01-01

    This paper presents an analytical solution for the Maximum-Torque-per-Ampere (MTPA) operation of synchronous machines (SM) with anisotropy and magnetic cross-coupling for the application in wind turbine systems and airborne wind energy systems. For a given reference torque, the analytical MTPA solution provides the optimal stator current references which produce the desired torque while minimizing the stator copper losses. From an implementation point of view, the proposed analytical method is appealing in terms of its fast online computation (compared to classical numerical methods) and its efficiency enhancement of the electrical drive system. The efficiency of the analytical MTPA operation, with and without consideration of cross-coupling, is compared to the conventional method with zero direct current. (paper)

  13. Superconductor Armature Winding for High Performance Electrical Machines

    Science.gov (United States)

    2016-12-05

    eddy -induced currents used for shielding. 3.1 SOLID SHIELD. The frequency of the induced current for our machines ... eddy   current  shields)   •  SuperSat     •  switch  reluctance  generators   •  AC  Homopolar   • Toroidal  (Gramme...higher than expected, due probably to highly conducting Nb sheath around the MgB2 filaments (the measured losses were coupling or eddy current

  14. Enertech 2-kW high-reliability wind system. Phase II. Fabrication and testing

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, J A; Johnson, B A

    1981-06-01

    A high-reliability wind machine rated for 2 kW in a 9 m/s wind has been developed. Activities are summarized that are centered on the fabrication and testing of prototypes of the wind machine. The test results verified that the wind machine met the power output specification and that the variable-pitch rotor effectively controlled the rotor speed for wind speeds up to 50 mph. Three prototypes of the wind machine were shipped to the Rocky Flats test center in September through November of 1979. Work was also performed to reduce the start-up wind speed. The start-up wind speed to the Enertech facility has been reduced to 4.5 m/s.

  15. Complex analysis of electromagnetic machines for vibro-impact technologies

    Science.gov (United States)

    Neyman, L. A.; Neyman, V. Yu

    2017-10-01

    For the implementation of high-energy impulse technologies of mechanical shock methods of secondary rock destruction, electromagnetic machines of vibro-impact action are of particular interest. Linear synchronous electromagnetic impact machine designs as a part of progress trend are considered where the head reciprocal motion is synchronized with 50 Hz power source pulses frequency applied to a winding or a system of windings. On the basis of identified differences of the head forced mechanical oscillation processes, merits and demerits of the work cycles of single or two-winding synchronous machine design variants are analyzed. Synchronous electromagnetic machines of a new design and principles of their control in a work cycle are presented. The specific half-wave interleaving of voltages applied to the windings allows reducing current amplitude and the influence of the impact drive on the power grid. To improve forced oscillation mode stability and precision, the new engineering solutions improving machines performances and exploitation conditions are proposed.

  16. Analysis of Properties of Induction Machine with Combined Parallel Star-Delta Stator Winding

    Czech Academy of Sciences Publication Activity Database

    Schreier, Luděk; Bendl, Jiří; Chomát, Miroslav

    2017-01-01

    Roč. 113, č. 1 (2017), s. 147-153 ISSN 0239-3646 R&D Projects: GA ČR(CZ) GA16-07795S Institutional support: RVO:61388998 Keywords : induction machine * parallel combined stator winding Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering

  17. Wind's tough dreamers

    Energy Technology Data Exchange (ETDEWEB)

    Gipe, P.

    1984-02-01

    The development of wind farms in California is reviewed. These wind farms are located at Carquinez Strait, Altamont Pass, Salinas Valley, Tehachapi Pass, Mojave, and San Gorgonio Pass. The machine size, installation, spacing, reliability, performance management, and financing are discussed.

  18. Accounting for the speed shear in wind turbine power performance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, R.

    2010-04-15

    The power curve of a wind turbine is the primary characteristic of the machine as it is the basis of the warranty for it power production. The current IEC standard for power performance measurement only requires the measurement of the wind speed at hub height and the air density to characterise the wind field in front of the turbine. However, with the growing size of the turbine rotors during the last years, the effect of the variations of the wind speed within the swept rotor area, and therefore of the power output, cannot be ignored any longer. Primary effects on the power performance are from the vertical wind shear and the turbulence intensity. The work presented in this thesis consists of the description and the investigation of a simple method to account for the wind speed shear in the power performance measurement. Ignoring this effect was shown to result in a power curve dependant on the shear condition, therefore on the season and the site. It was then proposed to use an equivalent wind speed accounting for the whole speed profile in front of the turbine. The method was first tested with aerodynamic simulations of a multi-megawatt wind turbine which demonstrated the decrease of the scatter in the power curve. A power curve defined in terms of this equivalent wind speed would be less dependant on the shear than the standard power curve. The equivalent wind speed method was then experimentally validated with lidar measurements. Two equivalent wind speed definitions were considered both resulting in the reduction of the scatter in the power curve. As a lidar wind profiler can measure the wind speed at several heights within the rotor span, the wind speed profile is described with more accuracy than with the power law model. The equivalent wind speed derived from measurements, including at least one measurement above hub height, resulted in a smaller scatter in the power curve than the equivalent wind speed derived from profiles extrapolated from measurements

  19. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  20. Electrical Machines: Turn-to-Turn Capacitance in Formed Windings with Rectangular Cross-Section Wire

    NARCIS (Netherlands)

    Djukic, Nenad; Encica, L.; Paulides, Johan

    2015-01-01

    Calculation of turn-to-turn capacitance (Ctt) in electrical machines (EMs) with formed windings with rectangular cross-section wire is presented. Three calculation methods are used for the calculation of Ctt in case of rectangular conductors – finite element (FE) method and two previously published

  1. Effect of unbalanced voltage on windings temperature, operational life and load carrying capacity of induction machine

    Energy Technology Data Exchange (ETDEWEB)

    Gnacinski, P. [Gdynia Maritime University, Department of Ship Electrical Power Engineering, Morska Street 83, 81-225 Gdynia (Poland)

    2008-04-15

    This paper investigates the influence of the CVUF angle on the windings temperature rise and the derating factor of an induction machine supplied with unbalanced voltage. The effect of simultaneous voltage unbalance and harmonics on its operational life is analyzed as well. The results of calculations and experimental investigations are presented for two induction cage machines of rated power 3 and 5.5 kW. (author)

  2. Model for Investigation of Operational Wind Power Plant Regimes with Doubly–Fed Asynchronous Machine in Power System

    Directory of Open Access Journals (Sweden)

    R. I. Mustafayev

    2012-01-01

    Full Text Available The paper presents methodology for mathematical modeling of power system (its part when jointly operated with wind power plants (stations that contain asynchronous doubly-fed machines used as generators. The essence and advantage of the methodology is that it allows efficiently to mate equations of doubly-fed asynchronous machines, written in the axes that rotate with the machine rotor speed with the equations of external electric power system, written in synchronously rotating axes.

  3. Wind turbine power performance verification in complex terrain and wind farms

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels; Gjerding, S.; Enevoldsen, P.

    2002-01-01

    is a power performance verification procedure for individual wind turbines. The third is a power performance measurement procedure of whole wind farms, and the fourth is a power performance measurement procedurefor non-grid (small) wind turbines. This report presents work that was made to support the basis......The IEC/EN 61400-12 Ed 1 standard for wind turbine power performance testing is being revised. The standard will be divided into four documents. The first one of these is more or less a revision of the existing document on power performance measurementson individual wind turbines. The second one...... then been investigated in more detail. The work has given rise to a range of conclusionsand recommendations regarding: guaranties on power curves in complex terrain; investors and bankers experience with verification of power curves; power performance in relation to regional correction curves for Denmark...

  4. A Case Study Regarding Influence of Solvers in Matlab/Simulink for Induction Machine Model in Wind Turbine Simulations

    DEFF Research Database (Denmark)

    Iov, F.; Blaabjerg, Frede; Hansen, A.D.

    2002-01-01

    In the last years Matlab/Simulink® has become the most used software for modelling and simulation of dynamic systems. Wind energy conversion systems are for example such systems because they contain parts with different range for the time constant: wind, turbine, generator, power electronics...... the different implementations of induction machine model, influence of the solvers from Simulink and how the simulation speed can be increase for a wind turbine....

  5. Coil Optimization for HTS Machines

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech

    An optimization approach of HTS coils in HTS synchronous machines (SM) is presented. The optimization is aimed at high power SM suitable for direct driven wind turbines applications. The optimization process was applied to a general radial flux machine with a peak air gap flux density of ~3T...... is suitable for which coil segment is presented. Thus, the performed study gives valuable input for the coil design of HTS machines ensuring optimal usage of HTS tapes....

  6. Using Unsupervised Machine Learning for Outlier Detection in Data to Improve Wind Power Production Prediction

    OpenAIRE

    Åkerberg, Ludvig

    2017-01-01

    The expansion of wind power for electrical energy production has increased in recent years and shows no signs of slowing down. This unpredictable source of energy has contributed to destabilization of the electrical grid causing the energy market prices to vary significantly on a daily basis. For energy producers and consumers to make good investments, methods have been developed to make predictions of wind power production. These methods are often based on machine learning were historical we...

  7. Transient stability enhancement of wind farms connected to a multi-machine power system by using an adaptive ANN-controlled SMES

    International Nuclear Information System (INIS)

    Muyeen, S.M.; Hasanien, Hany M.; Al-Durra, Ahmed

    2014-01-01

    Highlights: • We present an ANN-controlled SMES in this paper. • The objective is to enhance transient stability of WF connected to power system. • The control strategy depends on a PWM VSC and DC–DC converter. • The effectiveness of proposed controller is compared with PI controller. • The validity of the proposed system is verified by simulation results. - Abstract: This paper presents a novel adaptive artificial neural network (ANN)-controlled superconducting magnetic energy storage (SMES) system to enhance the transient stability of wind farms connected to a multi-machine power system during network disturbances. The control strategy of SMES depends mainly on a sinusoidal pulse width modulation (PWM) voltage source converter (VSC) and an adaptive ANN-controlled DC–DC converter using insulated gate bipolar transistors (IGBTs). The effectiveness of the proposed adaptive ANN-controlled SMES is then compared with that of proportional-integral (PI)-controlled SMES optimized by response surface methodology and genetic algorithm (RSM–GA) considering both of symmetrical and unsymmetrical faults. For realistic responses, real wind speed data and two-mass drive train model of wind turbine generator system is considered in the analyses. The validity of the proposed system is verified by the simulation results which are performed using the laboratory standard dynamic power system simulator PSCAD/EMTDC. Notably, the proposed adaptive ANN-controlled SMES enhances the transient stability of wind farms connected to a multi-machine power system

  8. HTS machine laboratory prototype

    DEFF Research Database (Denmark)

    machine. The machine comprises six stationary HTS field windings wound from both YBCO and BiSCOO tape operated at liquid nitrogen temperature and enclosed in a cryostat, and a three phase armature winding spinning at up to 300 rpm. This design has full functionality of HTS synchronous machines. The design...

  9. Wind turbine power performance verification in complex terrain and wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Friis Pedersen, T.; Gjerding, S.; Ingham, P.; Enevoldsen, P.; Kjaer Hansen, J.; Kanstrup Joergensen, H.

    2002-04-01

    The IEC/EN 61400-12 Ed 1 standard for wind turbine power performance testing is being revised. The standard will be divided into four documents. The first one of these is more or less a revision of the existing document on power performance measurements on individual wind turbines. The second one is a power performance verification procedure for individual wind turbines. The third is a power performance measurement procedure of whole wind farms, and the fourth is a power performance measurement procedure for non-grid (small) wind turbines. This report presents work that was made to support the basis for this standardisation work. The work addressed experience from several national and international research projects and contractual and field experience gained within the wind energy community on this matter. The work was wide ranging and addressed 'grey' areas of knowledge regarding existing methodologies, which has then been investigated in more detail. The work has given rise to a range of conclusions and recommendations regarding: guaranties on power curves in complex terrain; investors and bankers experience with verification of power curves; power performance in relation to regional correction curves for Denmark; anemometry and the influence of inclined flow. (au)

  10. Performance of spanish wind turbines

    International Nuclear Information System (INIS)

    Lago, C.

    1995-01-01

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1994, going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author)

  11. Design study of high-temperature superconducting generators for wind power systems

    Energy Technology Data Exchange (ETDEWEB)

    Maki, N [Technova Inc. 13th Fl. Imperial Hotel Tower, 1-chome, Chiyoda-ku, Tokyo 100-0011 (Japan)], E-mail: naokmaki@technova.co.jp

    2008-02-15

    Design study on high-temperature superconducting machines (HTSM) for wind power systems was carried out using specially developed design program. Outline of the design program was shown and the influence of machine parameters such as pole number, rotor outer diameter and synchronous reactance on the machine performance was clarified. Three kinds of generator structure are considered for wind power systems and the HTSM operated under highly magnetic saturated conditions with conventional rotor and stator has better performance than the other types of HTSM. Furthermore, conceptual structure of 8 MW, 20 pole HTSM adopting salient-pole rotor as in the case of water turbine generators and race-truck shaped HTS field windings like Japanese Maglev was shown.

  12. Design study of high-temperature superconducting generators for wind power systems

    International Nuclear Information System (INIS)

    Maki, N

    2008-01-01

    Design study on high-temperature superconducting machines (HTSM) for wind power systems was carried out using specially developed design program. Outline of the design program was shown and the influence of machine parameters such as pole number, rotor outer diameter and synchronous reactance on the machine performance was clarified. Three kinds of generator structure are considered for wind power systems and the HTSM operated under highly magnetic saturated conditions with conventional rotor and stator has better performance than the other types of HTSM. Furthermore, conceptual structure of 8 MW, 20 pole HTSM adopting salient-pole rotor as in the case of water turbine generators and race-truck shaped HTS field windings like Japanese Maglev was shown

  13. Implementing Machine Learning in the PCWG Tool

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, Andrew; Ding, Yu; Stuart, Peter

    2016-12-13

    The Power Curve Working Group (www.pcwg.org) is an ad-hoc industry-led group to investigate the performance of wind turbines in real-world conditions. As part of ongoing experience-sharing exercises, machine learning has been proposed as a possible way to predict turbine performance. This presentation provides some background information about machine learning and how it might be implemented in the PCWG exercises.

  14. An HTS machine laboratory prototype

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Træholt, Chresten

    2012-01-01

    This paper describes Superwind HTS machine laboratory setup which is a small scale HTS machine designed and build as a part of the efforts to identify and tackle some of the challenges the HTS machine design may face. One of the challenges of HTS machines is a Torque Transfer Element (TTE) which...... conduction compared to a shaft. The HTS machine was successfully cooled to 77K and tests have been performed. The IV curves of the HTS field winding employing 6 HTS coils indicate that two of the coils had been damaged. The maximal value of the torque during experiments of 78Nm was recorded. Loaded with 33...

  15. Superconducting three element synchronous ac machine

    International Nuclear Information System (INIS)

    Boyer, L.; Chabrerie, J.P.; Mailfert, A.; Renard, M.

    1975-01-01

    There is a growing interest in ac superconducting machines. Of several new concepts proposed for these machines in the last years one of the most promising seems to be the ''three elements'' concept which allows the cancellation of the torque acting on the superconducting field winding, thus overcoming some of the major contraints. This concept leads to a device of induction-type generator. A synchronous, three element superconducting ac machine is described, in which a room temperature, dc fed rotating winding is inserted between the superconducting field winding and the ac armature. The steady-state machine theory is developed, the flux linkages are established, and the torque expressions are derived. The condition for zero torque on the field winding, as well as the resulting electrical equations of the machine, are given. The theoretical behavior of the machine is studied, using phasor diagrams and assuming for the superconducting field winding either a constant current or a constant flux condition

  16. Wind energy resources assessment for Yanbo, Saudi Arabia

    International Nuclear Information System (INIS)

    Rehman, Shafiqur

    2004-01-01

    The paper presents long term wind data analysis in terms of annual, seasonal and diurnal variations at Yanbo, which is located on the west coast of Saudi Arabia. The wind speed and wind direction hourly data for a period of 14 years between 1970 and 1983 is used in the analysis. The analysis showed that the seasonal and diurnal pattern of wind speed matches the electricity load pattern of the location. Higher winds of the order of 5.0 m/s and more were observed during the summer months of the year and noon hours (09:00 to 16:00 h) of the day. The wind duration availability is discussed as the percent of hours during which the wind remained in certain wind speed intervals or bins. Wind energy calculations were performed using wind machines of sizes 150, 250, 600, 800, 1000, 1300, 1500, 2300 and 2500 kW rated power. Wind speed is found to remain above 3.5 m/s for 69% of the time during the year at 40, 50, 60, and 80 m above ground level. The energy production analysis showed higher production from wind machines of smaller sizes than the bigger ones for a wind farm of 30 MW installed capacity. Similarly, higher capacity factors were obtained for smaller wind machines compared to larger ones

  17. Electric machines with axial magnetic flux

    Science.gov (United States)

    Nuca, I.; Ambros, T.; Burduniuc, M.; Deaconu, S. I.; Turcanu, A.

    2018-01-01

    The paper contains information on the performance of axial machines compared to cylindrical ones. At the same time, various constructive schemes of synchronous electromechanical converters with permanent magnets and asynchronous with short-circuited rotor are presented. In the developed constructions, the aim is to maximize the usage of the material of the stator windings. The design elements of the axial machine magnetic system are presented. The FEMM application depicted the array of the magnetic field of an axial machine.

  18. Some aspects on wind turbines monitoring. General considerations and loads on horizontal wind turbines

    International Nuclear Information System (INIS)

    Cuerva, A.

    1996-01-01

    The concept Monitoring applied to the Wind Energy technology is similar to the definition used in other branches of Science or Engineering, this is knowing values of variables which have to do with a mechanic system, in our case a wind turbine. These mentioned parameters may have different relationships to our wind turbine; some of them come from the environment the machine is operating in, others, are a measure of how properly the machine is working, and finally, the rest are an assessment of the systems health during its life. In this chapter we will answer questions such as: What do we need to measure? Why is Monitoring mandatory (from the different points of view of people involved in this world)? How can we measure a wind turbine depending on our objectives (Technic, tools, guidance, recommendations, etc.)? And finally What can we expect in the near future? The author wants the reader to keep the idea in mind that Monitoring means the richest and most accurate knowledge on wind turbine's operation (Its environment, performances or health). This is the first step that allows us to optimize the operation mode of the machine and improve it (design, manufacturing, even the used modeling tools). When there is so much money involved, this fact becomes a must. (Author)

  19. Assessing the Performance of a Machine Learning Algorithm in Identifying Bubbles in Dust Emission

    Science.gov (United States)

    Xu, Duo; Offner, Stella S. R.

    2017-12-01

    Stellar feedback created by radiation and winds from massive stars plays a significant role in both physical and chemical evolution of molecular clouds. This energy and momentum leaves an identifiable signature (“bubbles”) that affects the dynamics and structure of the cloud. Most bubble searches are performed “by eye,” which is usually time-consuming, subjective, and difficult to calibrate. Automatic classifications based on machine learning make it possible to perform systematic, quantifiable, and repeatable searches for bubbles. We employ a previously developed machine learning algorithm, Brut, and quantitatively evaluate its performance in identifying bubbles using synthetic dust observations. We adopt magnetohydrodynamics simulations, which model stellar winds launching within turbulent molecular clouds, as an input to generate synthetic images. We use a publicly available three-dimensional dust continuum Monte Carlo radiative transfer code, HYPERION, to generate synthetic images of bubbles in three Spitzer bands (4.5, 8, and 24 μm). We designate half of our synthetic bubbles as a training set, which we use to train Brut along with citizen-science data from the Milky Way Project (MWP). We then assess Brut’s accuracy using the remaining synthetic observations. We find that Brut’s performance after retraining increases significantly, and it is able to identify yellow bubbles, which are likely associated with B-type stars. Brut continues to perform well on previously identified high-score bubbles, and over 10% of the MWP bubbles are reclassified as high-confidence bubbles, which were previously marginal or ambiguous detections in the MWP data. We also investigate the influence of the size of the training set, dust model, evolutionary stage, and background noise on bubble identification.

  20. Modelisation de la conversion electromecanique des machines ...

    African Journals Online (AJOL)

    These implemented models would constitute the module of possible generators that one could couple with a model of wind power engine in order to study, within the framework of a virtual laboratory, the performances of wind-driven systems of electricity generation. Cet article présente les modèles de machines électriques ...

  1. Dependency in State Transitions of Wind Turbines

    DEFF Research Database (Denmark)

    Herp, Jürgen; Ramezani, Mohammad Hossein; S. Nadimi, Esmaeil

    2017-01-01

    © 2017 IEEE. Turbine states and predicting the transition into failure states ahead of time is important in operation and maintenance of wind turbines. This study presents a method to monitor state transitions of a wind turbine based on the online inference on residuals. In a Bayesian framework...... be abstracted from generated data. Two models are presented: 1) assuming independence and 2) assuming dependence between states. In order to select the right models, machine learning is utilized to update hyperparameters on the conditional probabilities. Comparing fixed to learned hyperparameters points out...... the impact machine learning concepts have on the predictive performance of the presented models. In conclusion, a study on model residuals is performed to highlight the contribution to wind turbine monitoring. The presented algorithm can consistently detect the state transition under various configurations...

  2. Fuzzy logic based variable speed wind generation system

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, M.G. [Sao Paulo Univ., SP (Brazil). Escola Politecnica. PMC - Mecatronica; Bose, B.K. [Tennessee Univ., Knoxville, TN (United States). Dept. of Electrical Engineering; Spiegel, Ronal J. [Environmental Protection Agency, Research Triangle Park, NC (United States). Air and Energy Engineering Research Lab.

    1996-12-31

    This work demonstrates the successful application of fuzzy logic to enhance the performance and control of a variable speed wind generation system. A maximum power point tracker control is performed with three fuzzy controllers, without wind velocity measurement, and robust to wind vortex and turbine torque ripple. A squirrel cage induction generator feeds the power to a double-sided PWM converter system which pumps the power to a utility grid or supplies to an autonomous system. The fuzzy logic controller FLC-1 searches on-line the generator speed so that the aerodynamic efficiency of the wind turbine is optimized. A second fuzzy controller FLC-2 programs the machine flux by on-line search so as to optimize the machine-converter system wind vortex. Detailed analysis and simulation studies were performed for development of the control strategy and fuzzy algorithms, and a DSP TMS320C30 based hardware with C control software was built for the performance evaluation of a laboratory experimental set-up. The theoretical development was fully validated and the system is ready to be reproduced in a higher power installation. (author) 7 refs., 3 figs., 1 tab.

  3. Wind farm economics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    The economics of wind energy are changing rapidly, with improvements in machine performance and increases in size both contributing to reduce costs. These trends are examined and future costs assessed. Although the United Kingdom has regions of high wind speed, these are often in difficult terrain and construction costs are often higher than elsewhere in Europe. Nevertheless, wind energy costs are converging with those of the conventional thermal sources. At present, bank loan periods for wind projects are shorter than for thermal plant, which means that energy prices are higher. Ways of overcoming this problem are explored. It is important, also, to examine the value of wind energy. It is argued that wind energy has a higher value than energy from centralized plant, since it is fed into the low-voltage distribution network. (Author)

  4. Adaptive Controller for Drive System PMSG in Wind Turbine

    Directory of Open Access Journals (Sweden)

    Gnanambal

    2014-07-01

    Full Text Available This paper proposes adaptive Maximum Power Point Tracking (MPPT controller for Permanent Magnet Synchronous Generator (PMSG wind turbine and direct power control for grid side inverter for transformer less integration of wind energy. PMSG wind turbine with two back to back voltage source converters are considered more efficient, used to make real and reactive power control. The optimal control strategy has introduced for integrated control of PMSG Maximum Power Extraction, DC link voltage control and grid voltage support controls. Simulation model using MATLAB Simulink has developed to investigate the performance of proposed control techniques for PMSG wind turbine steady and variable wind conditions. This paper shows that the direct driven grid connected PMSG system has excellent performances and confirms the feasibility of the proposed techniques. While the wind turbine market continues to be dominated by conventional gear-driven wind turbine systems, the direct drive is attracting attention. PM machines are more attractive and superior with higher efficiency and energy yield, higher reliability, and power-to-weight ratio compared with electricity-excited machines.

  5. Some aspects on wind turbines monitoring. General considerations and loads on horizontal wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Cuerva, A.

    1996-12-01

    The concept Monitoring applied to the Wind Energy technology is similar to the definition used in other branches of Science or Engineering, this is knowing values of variables which have to do with a mechanic system, in our case a wind turbine. These mentioned parameters may have different relationships to our wind turbine; some of them come from the environment the machine is operating in, others, are a measure of how properly the machine is working, and finally, the rest are an assessment of the ``system`s health`` during its ``life``. In this chapter we will answer questions such as: What do we need to measure? Why is Monitoring mandatory (from the different points of view of people involved in this world)? How can we measure a wind turbine depending on our objectives (Technic, tools, guidance, recommendations, etc)? And finally What can we expect in the near future?. The author wants the reader to keep the idea in mind that Monitoring means the richest and most accurate knowledge on wind turbine`s operation (Its environment, performances of health). This is the first step that allows us to optimize the operation mode of the machine and improve it (design, manufacturing, even the used modeling tools). When there is so much money involved, this fact becomes a must. (Author)

  6. Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

    Science.gov (United States)

    Wallace, Brian D.

    A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

  7. Deterministic and probabilistic interval prediction for short-term wind power generation based on variational mode decomposition and machine learning methods

    International Nuclear Information System (INIS)

    Zhang, Yachao; Liu, Kaipei; Qin, Liang; An, Xueli

    2016-01-01

    Highlights: • Variational mode decomposition is adopted to process original wind power series. • A novel combined model based on machine learning methods is established. • An improved differential evolution algorithm is proposed for weight adjustment. • Probabilistic interval prediction is performed by quantile regression averaging. - Abstract: Due to the increasingly significant energy crisis nowadays, the exploitation and utilization of new clean energy gains more and more attention. As an important category of renewable energy, wind power generation has become the most rapidly growing renewable energy in China. However, the intermittency and volatility of wind power has restricted the large-scale integration of wind turbines into power systems. High-precision wind power forecasting is an effective measure to alleviate the negative influence of wind power generation on the power systems. In this paper, a novel combined model is proposed to improve the prediction performance for the short-term wind power forecasting. Variational mode decomposition is firstly adopted to handle the instability of the raw wind power series, and the subseries can be reconstructed by measuring sample entropy of the decomposed modes. Then the base models can be established for each subseries respectively. On this basis, the combined model is developed based on the optimal virtual prediction scheme, the weight matrix of which is dynamically adjusted by a self-adaptive multi-strategy differential evolution algorithm. Besides, a probabilistic interval prediction model based on quantile regression averaging and variational mode decomposition-based hybrid models is presented to quantify the potential risks of the wind power series. The simulation results indicate that: (1) the normalized mean absolute errors of the proposed combined model from one-step to three-step forecasting are 4.34%, 6.49% and 7.76%, respectively, which are much lower than those of the base models and the hybrid

  8. Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Mijatovic, Nenad

    A HTS machine could be a way to address some of the technical barriers offshore wind energy is about to face. Due to the superior power density of HTS machines, this technology could become a milestone on which many, including the wind industry, will rely in the future. The work presented...... in this thesis is a part of a larger endeavor, the Superwind project that focused on identifying the potentials that HTS machines could offer to the wind industry and addressing some of the challenges in the process. In order to identify these challenges, I have design and constructed a HTS machine experimental...... setup which is made to serve as precursor, leading towards an optimized HTS machine concept proposed for wind turbines. In part, the work presented in this thesis will focus on the description of the experimental setup and reasoning behind the choices made during the design. The setup comprises from...

  9. Wind energy economics

    International Nuclear Information System (INIS)

    Milborrow, D.J.

    1995-01-01

    The economics of wind energy have improved rapidly in the past few years, with improvements in machine performance and increases in size both contributing to reduce costs. These trends are examined and future costs assessed. As bank loan periods for wind projects are shorter than for thermal plant, the effect on the price of wind energy is discussed. It is argued that wind energy has a higher value than that of centralised plant, since it is fed into the low voltage distribution network and it follows that the price of wind energy is converging with its value. The paper also includes a brief review of the capacity credit of wind plant and an assessment of the cost penalties which are incurred due to the need to hold extra plant on part load. These penalties are shown to be small. (author)

  10. Site calibration for the wind turbine performance evaluation

    International Nuclear Information System (INIS)

    Nam, Yoon Su; Yoo, Neung Soo; Lee, Jung Wan

    2004-01-01

    The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several method on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the TaeKwanRyung test site are presented using three-month wind data from a reference meteorological mast and the other mast temporarily installed at the site of wind turbine. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed

  11. Using machine learning to predict wind turbine power output

    International Nuclear Information System (INIS)

    Clifton, A; Kilcher, L; Lundquist, J K; Fleming, P

    2013-01-01

    Wind turbine power output is known to be a strong function of wind speed, but is also affected by turbulence and shear. In this work, new aerostructural simulations of a generic 1.5 MW turbine are used to rank atmospheric influences on power output. Most significant is the hub height wind speed, followed by hub height turbulence intensity and then wind speed shear across the rotor disk. These simulation data are used to train regression trees that predict the turbine response for any combination of wind speed, turbulence intensity, and wind shear that might be expected at a turbine site. For a randomly selected atmospheric condition, the accuracy of the regression tree power predictions is three times higher than that from the traditional power curve methodology. The regression tree method can also be applied to turbine test data and used to predict turbine performance at a new site. No new data are required in comparison to the data that are usually collected for a wind resource assessment. Implementing the method requires turbine manufacturers to create a turbine regression tree model from test site data. Such an approach could significantly reduce bias in power predictions that arise because of the different turbulence and shear at the new site, compared to the test site. (letter)

  12. Performance of Wind Pump Prototype

    African Journals Online (AJOL)

    Mulu

    Mekelle University, Mekelle, Ethiopia (*mul_at@yahoo.com). ABSTRACT. A wind ... balanced rotor power and reciprocating pump, hence did not consider the effect of pump size. ... Keywords: Wind pump, Windmill, Performance testing, Pump efficiency, Pump discharge, ... Unfortunately, in rural places, where the houses are.

  13. Performance and portability of the SciBy virtual machine

    DEFF Research Database (Denmark)

    Andersen, Rasmus; Vinter, Brian

    2010-01-01

    The Scientific Bytecode Virtual Machine is a virtual machine designed specifically for performance, security, and portability of scientific applications deployed in a Grid environment. The performance overhead normally incurred by virtual machines is mitigated using native optimized scientific li...

  14. Fluid-structure interaction modeling of wind turbines: simulating the full machine

    Science.gov (United States)

    Hsu, Ming-Chen; Bazilevs, Yuri

    2012-12-01

    In this paper we present our aerodynamics and fluid-structure interaction (FSI) computational techniques that enable dynamic, fully coupled, 3D FSI simulation of wind turbines at full scale, and in the presence of the nacelle and tower (i.e., simulation of the "full machine"). For the interaction of wind and flexible blades we employ a nonmatching interface discretization approach, where the aerodynamics is computed using a low-order finite-element-based ALE-VMS technique, while the rotor blades are modeled as thin composite shells discretized using NURBS-based isogeometric analysis (IGA). We find that coupling FEM and IGA in this manner gives a good combination of efficiency, accuracy, and flexibility of the computational procedures for wind turbine FSI. The interaction between the rotor and tower is handled using a non-overlapping sliding-interface approach, where both moving- and stationary-domain formulations of aerodynamics are employed. At the fluid-structure and sliding interfaces, the kinematic and traction continuity is enforced weakly, which is a key ingredient of the proposed numerical methodology. We present several simulations of a three-blade 5~MW wind turbine, with and without the tower. We find that, in the case of no tower, the presence of the sliding interface has no effect on the prediction of aerodynamic loads on the rotor. From this we conclude that weak enforcement of the kinematics gives just as accurate results as the strong enforcement, and thus enables the simulation of rotor-tower interaction (as well as other applications involving mechanical components in relative motion). We also find that the blade passing the tower produces a 10-12 % drop (per blade) in the aerodynamic torque. We feel this finding may be important when it comes to the fatigue-life analysis and prediction for wind turbine blades.

  15. Financial analysis of wind power projects

    International Nuclear Information System (INIS)

    Juanico, Luis E.; Bergallo, Juan E.

    1999-01-01

    In this work a financial assessment of the economic competitiveness of wind power projects in Argentina compared with other no CO 2 emission sources, such as nuclear, was developed. Argentina has a market driven electrical grid system, and no greenhouse gas emissions penalty taxes, together with a very low natural gas cost and a sustained nuclear development program. For the financial analysis an average wind velocity source of 8 m/s, on several wind farms (from 2 machines to 60) built with new technology wind generators (750 kilowatts power, 900 dollar/kilowatt cost) operating over 20 years, was considered. The leveled cost obtained is decreasing while the number of machines is increasing, from 0,130 dollar/kilowatt-hour to 0,090 dollar/kilowatts-hour. This poor performance can be partially explained considering the higher interest rates in the argentine financial market (15%) than the ones in developed countries

  16. Studies on Nb3Sn field coils for superconducting machine

    International Nuclear Information System (INIS)

    Fujino, H.; Nose, S.

    1981-01-01

    This paper describes experimental studies on several coils wound with multifilamentary (MF) Nb 3 Sn cables with reinforcing strip for superconducting rotating machine application. To use a Nb 3 Sn superconductor to field winding of a rotating machine, several coil performances of pre-reacted, bronze processed and stranded MF Nb 3 Sn cables were investigated, mainly in relation to stress effect. Bending strain up to 0.64% in strand and winding stress of 5 kg/mm 2 have resulted in nondegradation in coil performance. A pair of impregnated race-track coils designed for a 30 MVA synchronous condenser was energized successfully up to 80% of critical current without quench. 8 refs

  17. Non-conventional rule of making a periodically varying different-pole magnetic field in low-power alternating current electrical machines with using ring coils in multiphase armature winding

    Science.gov (United States)

    Plastun, A. T.; Tikhonova, O. V.; Malygin, I. V.

    2018-02-01

    The paper presents methods of making a periodically varying different-pole magnetic field in low-power electrical machines. Authors consider classical designs of electrical machines and machines with ring windings in armature, structural features and calculated parameters of magnetic circuit for these machines.

  18. Effect of wind energy system performance on optimal renewable energy model - an analysis

    International Nuclear Information System (INIS)

    Iniyan, S.; Jagadeesan, T.R.

    1998-01-01

    The Optimal Renewable Energy Model (OREM) has been developed to determine the optimum level of renewable energy sources utilisation in India for the year 2020-21. The model aims at minimising cost/efficiency ratio and determines the optimum allocation of different renewable energy sources for various end-uses. The extent of social acceptance level, potential limit, demand and reliability will decide the renewable energy distribution pattern and are hence used as constraints in the model. In this paper, the performance and reliability of wind energy system and its effects on OREM model has been analysed. The demonstration windfarm (4 MW) which is situated in Muppandal, a village in the southern part of India, has been selected for the study. The windfarm has 20 wind turbine machines of 200 KW capacity . The average technical availability, real availability and capacity factor have been analysed from 1991 to 1995 and they are found to be 94.1%, 76.4% and 25.5% respectively. The reliability factor of wind energy systems is found to be 0.5 at 10,000 hours. The OREM model is analysed considering the above said factors for wind energy system, solar energy system and biomass energy systems. The model selects wind energy for pumping end-use to an extent of 0.3153 x10 15 KJ. (Author)

  19. Multi-component wind measurements of wind turbine wakes performed with three LiDARs

    Science.gov (United States)

    Iungo, G. V.; Wu, Y.-T.; Porté-Agel, F.

    2012-04-01

    Field measurements of the wake flow produced from the interaction between atmospheric boundary layer and a wind turbine are performed with three wind LiDARs. The tested wind turbine is a 2 MW Enercon E-70 located in Collonges, Switzerland. First, accuracy of mean values and frequency resolution of the wind measurements are surveyed as a function of the number of laser rays emitted for each measurement. Indeed, measurements performed with one single ray allow maximizing sampling frequency, thus characterizing wake turbulence. On the other hand, if the number of emitted rays is increased accuracy of mean wind is increased due to the longer sampling period. Subsequently, two-dimensional measurements with a single LiDAR are carried out over vertical sections of the wind turbine wake and mean wake flow is obtained by averaging 2D measurements consecutively performed. The high spatial resolution of the used LiDAR allows characterizing in details velocity defect present in the central part of the wake and its downstream recovery. Single LiDAR measurements are also performed by staring the laser beam at fixed directions for a sampling period of about ten minutes and maximizing the sampling frequency in order to characterize wake turbulence. From these tests wind fluctuation peaks are detected in the wind turbine wake at blade top-tip height for different downstream locations. The magnitude of these turbulence peaks is generally reduced by moving downstream. This increased turbulence level at blade top-tip height observed for a real wind turbine has been already detected from previous wind tunnel tests and Large Eddy simulations, thus confirming the presence of a source of dangerous fatigue loads for following wind turbines within a wind farm. Furthermore, the proper characterization of wind fluctuations through LiDAR measurements is proved by the detection of the inertial subrange from spectral analysis of these velocity signals. Finally, simultaneous measurements with two

  20. High Temperature Superconductor Machine Prototype

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Træholt, Chresten

    2011-01-01

    A versatile testing platform for a High Temperature Superconductor (HTS) machine has been constructed. The stationary HTS field winding can carry up to 10 coils and it is operated at a temperature of 77K. The rotating armature is at room temperature. Test results and performance for the HTS field...

  1. Effect of power quality on windings temperature of marine induction motors. Part I: Machine model

    Energy Technology Data Exchange (ETDEWEB)

    Gnacinski, P. [Gdynia Maritime Univ., Dept. of Ship Electrical Power Engineering, Morska Str. 83, 81-225 Gdynia (Poland)

    2009-10-15

    Marine induction machines are exposed to various power quality disturbances appearing simultaneously in ship power systems: frequency and voltage rms value deviation, voltage unbalance and voltage waveform distortions. As a result, marine induction motors can be seriously overheated due to lowered supply voltage quality. Improvement of the protection of marine induction machines requires an appropriate method of power quality assessment and modification of the power quality regulations of ship classification societies. This paper presents an analytical model of an induction cage machine supplied with voltage of lowered quality, used in part II of the work (effect of power quality on windings temperature of marine induction motors. Part II. Results of investigations and recommendations for related regulations) for power quality assessment in ship power systems, and for justification of the new power quality regulations proposal. The presented model is suitable for implementation in an on-line measurement system. (author)

  2. Design of advanced airfoil for stall-regulated wind turbines

    Directory of Open Access Journals (Sweden)

    F. Grasso

    2017-07-01

    Full Text Available Nowadays, all the modern megawatt-class wind turbines make use of pitch control to optimise the rotor performance and control the turbine. However, for kilowatt-range machines, stall-regulated solutions are still attractive and largely used for their simplicity and robustness. In the design phase, the aerodynamics plays a crucial role, especially concerning the selection/design of the necessary airfoils. This is because the airfoil performance is supposed to guarantee high wind turbine performance but also the necessary machine control capabilities. In the present work, the design of a new airfoil dedicated to stall machines is discussed. The design strategy makes use of a numerical optimisation scheme, where a gradient-based algorithm is coupled with the RFOIL code and an original Bezier-curves-based parameterisation to describe the airfoil shape. The performances of the new airfoil are compared in free- and fixed-transition conditions. In addition, the performance of the rotor is analysed, comparing the impact of the new geometry with alternative candidates. The results show that the new airfoil offers better performance and control than existing candidates do.

  3. Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    van Dam, J.; Jager, D.

    2010-02-01

    This report summarizes the results of a power performance test that NREL conducted on the ARE 442 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the ARE 442 is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  4. Wind Energy Development in India and a Methodology for Evaluating Performance of Wind Farm Clusters

    Directory of Open Access Journals (Sweden)

    Sanjeev H. Kulkarni

    2016-01-01

    Full Text Available With maturity of advanced technologies and urgent requirement for maintaining a healthy environment with reasonable price, India is moving towards a trend of generating electricity from renewable resources. Wind energy production, with its relatively safer and positive environmental characteristics, has evolved from a marginal activity into a multibillion dollar industry today. Wind energy power plants, also known as wind farms, comprise multiple wind turbines. Though there are several wind-mill clusters producing energy in different geographical locations across the world, evaluating their performance is a complex task and is an important focus for stakeholders. In this work an attempt is made to estimate the performance of wind clusters employing a multicriteria approach. Multiple factors that affect wind farm operations are analyzed by taking experts opinions, and a performance ranking of the wind farms is generated. The weights of the selection criteria are determined by pairwise comparison matrices of the Analytic Hierarchy Process (AHP. The proposed methodology evaluates wind farm performance based on technical, economic, environmental, and sociological indicators. Both qualitative and quantitative parameters were considered. Empirical data were collected through questionnaire from the selected wind farms of Belagavi district in the Indian State of Karnataka. This proposed methodology is a useful tool for cluster analysis.

  5. Performance of spanish wind turbines. Year 1995

    International Nuclear Information System (INIS)

    Lago, C.

    1997-01-01

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1995 going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author)

  6. Performance of spanish wind turbines. Year 1996

    International Nuclear Information System (INIS)

    Lago, C.

    1998-01-01

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1996 going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author) 4 refs

  7. Final Report - Certifying the Performance of Small Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, Larry [Small Wind Certification Council, Clifton Park, NY (United States)

    2015-08-28

    The Small Wind Certification Council (SWCC) created a successful accredited certification program for small and medium wind turbines using the funding from this grant. SWCC certifies small turbines (200 square meters of swept area or less) to the American Wind Energy Association (AWEA) Small Wind Turbine Performance and Safety Standard (AWEA Standard 9.1 – 2009). SWCC also certifies medium wind turbines to the International Electrical Commission (IEC) Power Performance Standard (IEC 61400-12-1) and Acoustic Performance Standard (IEC 61400-11).

  8. Thermodynamic performance assessment of wind energy systems: An application

    International Nuclear Information System (INIS)

    Redha, Adel Mohammed; Dincer, Ibrahim; Gadalla, Mohamed

    2011-01-01

    In this paper, the performance of wind energy system is assessed thermodynamically, from resource and technology perspectives. The thermodynamic characteristics of wind through energy and exergy analyses are considered and both energetic and exergetic efficiencies are studied. Wind speed is affected by air temperature and pressure and has a subsequent effect on wind turbine performance based on wind reference temperature and Bernoulli's equation. VESTAS V52 wind turbine is selected for (Sharjah/UAE). Energy and exergy efficiency equations for wind energy systems are further developed for practical applications. The results show that there are noticeable differences between energy and exergy efficiencies and that exergetic efficiency reflects the right/actual performance. Finally, exergy analysis has been proven to be the right tool used in design, simulation, and performance evaluation of all renewable energy systems. -- Highlights: → In this research the performance of wind energy system is assessed thermodynamically, from resource and technology perspectives. → Energy and exergy equations for wind energy systems are further developed for practical applications. → Thermodynamic characteristics of wind turbine systems through energetic and exergetic efficiencies are evaluated from January till March 2010. → Exergy efficiency describes the system irreversibility and the minimum irreversibility exists when the wind speed reaches 11 m/s. → The power production during March was about 17% higher than the month of February and 66% higher than January.

  9. Comparison of wind mill cluster performance: A multicriteria approach

    Energy Technology Data Exchange (ETDEWEB)

    Rajakumar, D.G.; Nagesha, N. [Visvesvaraya Technological Univ., Karnataka (India)

    2012-07-01

    Energy is a crucial input for the economic and social development of any nation. Both renewable and non-renewable energy contribute in meeting the total requirement of the economy. As an affordable and clean energy source, wind energy is amongst the world's fastest growing renewable energy forms. Though there are several wind-mill clusters producing energy in different geographical locations, evaluating their performance is a complex task and not much of literature is available in this area. In this backdrop, an attempt is made in the current paper to estimate the performance of a wind-mill cluster through an index called Cluster Performance Index (CPI) adopting a multi-criteria approach. The proposed CPI comprises four criteria viz., Technical Performance Indicators (TePI), Economic Performance Indicators (EcPI), Environmental Performance Indicators (EnPI), and Sociological Performance Indicators (SoPI). Under each performance criterion a total of ten parameters are considered with five subjective and five objective oriented responses. The methodology is implemented by collecting empirical data from three wind-mill clusters located at Chitradurga, Davangere, and Gadag in the southern Indian State of Karnataka. Totally fifteen different stake holders are consulted through a set of structured researcher administered questionnaire to collect the relevant data in each wind farm. Stake holders involved engineers working in wind farms, wind farm developers, Government officials from energy department and a few selected residential people near the wind farms. The results of the study revealed that Chitradurga wind farm performed much better with a CPI of 45.267 as compared to Gadag (CPI of 28.362) and Davangere (CPI of 19.040) wind farms. (Author)

  10. Electric machines

    CERN Document Server

    Gross, Charles A

    2006-01-01

    BASIC ELECTROMAGNETIC CONCEPTSBasic Magnetic ConceptsMagnetically Linear Systems: Magnetic CircuitsVoltage, Current, and Magnetic Field InteractionsMagnetic Properties of MaterialsNonlinear Magnetic Circuit AnalysisPermanent MagnetsSuperconducting MagnetsThe Fundamental Translational EM MachineThe Fundamental Rotational EM MachineMultiwinding EM SystemsLeakage FluxThe Concept of Ratings in EM SystemsSummaryProblemsTRANSFORMERSThe Ideal n-Winding TransformerTransformer Ratings and Per-Unit ScalingThe Nonideal Three-Winding TransformerThe Nonideal Two-Winding TransformerTransformer Efficiency and Voltage RegulationPractical ConsiderationsThe AutotransformerOperation of Transformers in Three-Phase EnvironmentsSequence Circuit Models for Three-Phase Transformer AnalysisHarmonics in TransformersSummaryProblemsBASIC MECHANICAL CONSIDERATIONSSome General PerspectivesEfficiencyLoad Torque-Speed CharacteristicsMass Polar Moment of InertiaGearingOperating ModesTranslational SystemsA Comprehensive Example: The ElevatorP...

  11. Using Machine Learning to Predict Student Performance

    OpenAIRE

    Pojon, Murat

    2017-01-01

    This thesis examines the application of machine learning algorithms to predict whether a student will be successful or not. The specific focus of the thesis is the comparison of machine learning methods and feature engineering techniques in terms of how much they improve the prediction performance. Three different machine learning methods were used in this thesis. They are linear regression, decision trees, and naïve Bayes classification. Feature engineering, the process of modification ...

  12. The Bearingless Electrical Machine

    Science.gov (United States)

    Bichsel, J.

    1992-01-01

    Electromagnetic bearings allow the suspension of solids. For rotary applications, the most important physical effect is the force of a magnetic circuit to a high permeable armature, called the MAXWELL force. Contrary to the commonly used MAXWELL bearings, the bearingless electrical machine will take advantage of the reaction force of a conductor carrying a current in a magnetic field. This kind of force, called Lorentz force, generates the torque in direct current, asynchronous and synchronous machines. The magnetic field, which already exists in electrical machines and helps to build up the torque, can also be used for the suspension of the rotor. Besides the normal winding of the stator, a special winding was added, which generates forces for levitation. So a radial bearing, which is integrated directly in the active part of the machine, and the motor use the laminated core simultaneously. The winding was constructed for the levitating forces in a special way so that commercially available standard ac inverters for drives can be used. Besides wholly magnetic suspended machines, there is a wide range of applications for normal drives with ball bearings. Resonances of the rotor, especially critical speeds, can be damped actively.

  13. Short-Term Wind Speed Forecasting Using the Data Processing Approach and the Support Vector Machine Model Optimized by the Improved Cuckoo Search Parameter Estimation Algorithm

    Directory of Open Access Journals (Sweden)

    Chen Wang

    2016-01-01

    Full Text Available Power systems could be at risk when the power-grid collapse accident occurs. As a clean and renewable resource, wind energy plays an increasingly vital role in reducing air pollution and wind power generation becomes an important way to produce electrical power. Therefore, accurate wind power and wind speed forecasting are in need. In this research, a novel short-term wind speed forecasting portfolio has been proposed using the following three procedures: (I data preprocessing: apart from the regular normalization preprocessing, the data are preprocessed through empirical model decomposition (EMD, which reduces the effect of noise on the wind speed data; (II artificially intelligent parameter optimization introduction: the unknown parameters in the support vector machine (SVM model are optimized by the cuckoo search (CS algorithm; (III parameter optimization approach modification: an improved parameter optimization approach, called the SDCS model, based on the CS algorithm and the steepest descent (SD method is proposed. The comparison results show that the simple and effective portfolio EMD-SDCS-SVM produces promising predictions and has better performance than the individual forecasting components, with very small root mean squared errors and mean absolute percentage errors.

  14. Wind effects on RVACS performance

    International Nuclear Information System (INIS)

    Tzanos, C.

    1995-01-01

    The reactor vessel auxillary cooling system (RVACS) is a passive liquid-metal reactor decay-heat removal system. The RVACS performance is a function of the pressure difference between air flow inlet and outlet, of the air inlet temperature, of the air density variation along the flow path, and of the pressure loss characteristics of the path. The pressure difference can be affected by wind speed and direction. The objective of this project was to investigate the effects of wind on the performance of the RVACS, specifically, the heat release through the stacks, of a liquid-metal reactor

  15. Development of a representative model of a wind turbine in order to study the installation of several machines on a wind park

    International Nuclear Information System (INIS)

    Jourieh, M.

    2007-12-01

    This thesis is devoted to the study of aerodynamics in wind turbines. It is divided into two main parts, one is experimental, and the other deals with modelling and numerical simulation. The velocity field downstream from a three-bladed wind turbine with a horizontal axis is explored in the wind tunnel at ENSAM-Paris. Two measurement techniques are used: hot wire anemometry and Particle Image Velocimetry (PIV). Experimental work gives a clear idea of the structure of the near wake and provides useful data to validate the numerical simulations and the hybrid models which are studied in this thesis. In the work concerning numerical simulation, two hybrid models are defined and implemented: a model of actuator disc and a model of actuator cylinder, coupled with a simulation based on the numerical resolution of the Navier-Stokes equations. These models are validated by the power of the wind turbine and on the velocity field in the near wake of the rotor. The numerical results are compared with the experimental data resulting from the tests carried out by the NREL for NREL phase II and VI cases. The experimental and numerical velocity fields are also compared in the wake of a wind turbine Rutland 503. In both validation cases, power and wake, the experimental data are in accordance with the results provided by the hybrid models. After this validation, the interaction between several wind turbines is studied and quantified. The tested hybrid models are also used to study the interaction between identical wind turbines placed one behind the other. The obtained results highlight the effect of spacing between the machines as well as the effect of free stream velocity. (author)

  16. Performance and Reliability of Wind Turbines: A Review

    Directory of Open Access Journals (Sweden)

    Sebastian Pfaffel

    2017-11-01

    Full Text Available Performance (availability and yield and reliability of wind turbines can make the difference between success and failure of wind farm projects and these factors are vital to decrease the cost of energy. During the last years, several initiatives started to gather data on the performance and reliability of wind turbines on- and offshore and published findings in different journals and conferences. Even though the scopes of the different initiatives are similar, every initiative follows a different approach and results are therefore difficult to compare. The present paper faces this issue, collects results of different initiatives and harmonizes the results. A short description and assessment of every considered data source is provided. To enable this comparison, the existing reliability characteristics are mapped to a system structure according to the Reference Designation System for Power Plants (RDS-PP®. The review shows a wide variation in the performance and reliability metrics of the individual initiatives. Especially the comparison on onshore wind turbines reveals significant differences between the results. Only a few publications are available on offshore wind turbines and the results show an increasing performance and reliability of offshore wind turbines since the first offshore wind farms were erected and monitored.

  17. Performance comparison of wind park configurations

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, Stefan

    2003-07-01

    In this report, layouts of various large-scale wind parks, both AC as well as DC, are investigated. Loss modelling of the wind park components as well as calculations of the energy capture of the turbines using various electrical systems are performed, and the energy production cost of the various park configurations is determined. It was found that from an energy capture point of view, the difference in energy production between various wind turbine systems is very small. In addition, a study of the suitability of various DC/DC-converters is made. Three DC/DC-converters, Boost, Full Bridge and Full Bridge Isolated Boost, are found to be interesting candidates as the 'transformer' component in potential DC-based wind parks. Of all the investigated wind park configurations, the wind park with the series connected DC wind turbines seems to have the best potential to give the lowest energy production cost, if the transmission distance is longer then 10-20 km.

  18. An analytical investigation of the performance of wind-turbines with gyrocopter-like rotors

    Energy Technology Data Exchange (ETDEWEB)

    Kentfield, J.A.C.; Brophy, D.C. [Univ. of Calgary, Alberta (Canada)

    1997-12-31

    The performance was predicted of a wind-turbine, intended for electrical power generation, the rotor of which is similar in configuration to the rotor of an autogyro or gyrocopter as originated by Cierva. Hence the rotor axis of spin is tilted downwind, for maximum power production, by an angle of 40{degrees} to 50{degrees} relative to the vertical with power regulation by modulation of the tilt angle. Because the rotor of a Cierva turbine generates lift the simple, non-twisted, fixed-pitch blades {open_quotes}fly{close_quotes} and are self supporting thereby eliminating flap-wise bending moments when the blades are hinged at their roots. It was found from the analysis that it is possible to reduce tower bending moments substantially relative to a conventional horizontal axis turbine of equal power output and also, for equal maximum hub heights and blade tip altitudes, a Cierva turbine is capable, at a prescribed wind speed, of a greater power output than a conventional horizontal axis machine.

  19. Power Performance Verification of a Wind Farm Using the Friedman's Test.

    Science.gov (United States)

    Hernandez, Wilmar; López-Presa, José Luis; Maldonado-Correa, Jorge L

    2016-06-03

    In this paper, a method of verification of the power performance of a wind farm is presented. This method is based on the Friedman's test, which is a nonparametric statistical inference technique, and it uses the information that is collected by the SCADA system from the sensors embedded in the wind turbines in order to carry out the power performance verification of a wind farm. Here, the guaranteed power curve of the wind turbines is used as one more wind turbine of the wind farm under assessment, and a multiple comparison method is used to investigate differences between pairs of wind turbines with respect to their power performance. The proposed method says whether the power performance of the specific wind farm under assessment differs significantly from what would be expected, and it also allows wind farm owners to know whether their wind farm has either a perfect power performance or an acceptable power performance. Finally, the power performance verification of an actual wind farm is carried out. The results of the application of the proposed method showed that the power performance of the specific wind farm under assessment was acceptable.

  20. Design of High Performance Permanent-Magnet Synchronous Wind Generators

    Directory of Open Access Journals (Sweden)

    Chun-Yu Hsiao

    2014-11-01

    Full Text Available This paper is devoted to the analysis and design of high performance permanent-magnet synchronous wind generators (PSWGs. A systematic and sequential methodology for the design of PMSGs is proposed with a high performance wind generator as a design model. Aiming at high induced voltage, low harmonic distortion as well as high generator efficiency, optimal generator parameters such as pole-arc to pole-pitch ratio and stator-slot-shoes dimension, etc. are determined with the proposed technique using Maxwell 2-D, Matlab software and the Taguchi method. The proposed double three-phase and six-phase winding configurations, which consist of six windings in the stator, can provide evenly distributed current for versatile applications regarding the voltage and current demands for practical consideration. Specifically, windings are connected in series to increase the output voltage at low wind speed, and in parallel during high wind speed to generate electricity even when either one winding fails, thereby enhancing the reliability as well. A PMSG is designed and implemented based on the proposed method. When the simulation is performed with a 6 Ω load, the output power for the double three-phase winding and six-phase winding are correspondingly 10.64 and 11.13 kW. In addition, 24 Ω load experiments show that the efficiencies of double three-phase winding and six-phase winding are 96.56% and 98.54%, respectively, verifying the proposed high performance operation.

  1. Advanced control of direct-driven PMSG generator in wind turbine system

    Directory of Open Access Journals (Sweden)

    Gajewski Piotr

    2016-12-01

    Full Text Available The paper presents the advanced control system of the wind energy conversion with a variable speed wind turbine. The considered system consists of a wind turbine with the permanent magnet synchronous generator (PMSG, machine side converter (MSC, grid side converter (GSC and control circuits. The mathematical models of a wind turbine system, the PMSG generator and converters have been described. The control algorithms of the converter systems based on the methods of vector control have been applied. In the advanced control system of the machine side converter the optimal MPPT control method has been used. Additionally the pitch control scheme is included in order to achieve the limitation of maximum power and to prevent mechanical damage of the wind turbine. In the control system of the grid side converter the control of active and reactive power has been applied with the application of Voltage Oriented Control (VOC. The performance of the considered wind energy system has been studied by digital simulation. The results of simulation studies confirmed the good effectiveness of the considered wind turbine system and very good performance of the proposed methods of vector control and control systems.

  2. Economic performance indicators of wind energy based on wind speed stochastic modeling

    International Nuclear Information System (INIS)

    D’Amico, Guglielmo; Petroni, Filippo; Prattico, Flavio

    2015-01-01

    Highlights: • We propose a new and different wind energy production indicator. • We compute financial profitability of potential wind power sites. • The wind speed process is modeled as an indexed semi-Markov chain. • We check if the wind energy is a good investment with and without incentives. - Abstract: We propose the computation of different wind energy production indicators and financial profitability of potential wind power sites. The computation is performed by modeling the wind speed process as an indexed semi-Markov chain to predict and simulate the wind speed dynamics. We demonstrate that the indexed semi-Markov chain approach enables reproducing the indicators calculated on real data. Two different time horizons of 15 and 30 years are analyzed. In the first case we consider the government incentives on the energy price now present in Italy, while in the second case the incentives have not been taken into account

  3. Representational Learning for Fault Diagnosis of Wind Turbine Equipment: A Multi-Layered Extreme Learning Machines Approach

    Directory of Open Access Journals (Sweden)

    Zhi-Xin Yang

    2016-05-01

    Full Text Available Reliable and quick response fault diagnosis is crucial for the wind turbine generator system (WTGS to avoid unplanned interruption and to reduce the maintenance cost. However, the conditional data generated from WTGS operating in a tough environment is always dynamical and high-dimensional. To address these challenges, we propose a new fault diagnosis scheme which is composed of multiple extreme learning machines (ELM in a hierarchical structure, where a forwarding list of ELM layers is concatenated and each of them is processed independently for its corresponding role. The framework enables both representational feature learning and fault classification. The multi-layered ELM based representational learning covers functions including data preprocessing, feature extraction and dimension reduction. An ELM based autoencoder is trained to generate a hidden layer output weight matrix, which is then used to transform the input dataset into a new feature representation. Compared with the traditional feature extraction methods which may empirically wipe off some “insignificant’ feature information that in fact conveys certain undiscovered important knowledge, the introduced representational learning method could overcome the loss of information content. The computed output weight matrix projects the high dimensional input vector into a compressed and orthogonally weighted distribution. The last single layer of ELM is applied for fault classification. Unlike the greedy layer wise learning method adopted in back propagation based deep learning (DL, the proposed framework does not need iterative fine-tuning of parameters. To evaluate its experimental performance, comparison tests are carried out on a wind turbine generator simulator. The results show that the proposed diagnostic framework achieves the best performance among the compared approaches in terms of accuracy and efficiency in multiple faults detection of wind turbines.

  4. A Performance Survey on Stack-based and Register-based Virtual Machines

    OpenAIRE

    Fang, Ruijie; Liu, Siqi

    2016-01-01

    Virtual machines have been widely adapted for high-level programming language implementations and for providing a degree of platform neutrality. As the overall use and adaptation of virtual machines grow, the overall performance of virtual machines has become a widely-discussed topic. In this paper, we present a survey on the performance differences of the two most widely adapted types of virtual machines - the stack-based virtual machine and the register-based virtual machine - using various...

  5. Method of Relative Magnitudes for Calculating Magnetic Fluxes in Electrical Machine

    Directory of Open Access Journals (Sweden)

    Oleg A.

    2018-03-01

    Full Text Available Introduction: The article presents the study results of the model of an asynchronous electric motor carried out by the author within the framework of the Priorities Research Program “Research and development in the priority areas of development of Russia’s scientific and technical complex for 2014–2020”. Materials and Methods: A model of an idealized asynchronous machine (with sinusoidal distribution of magnetic induction in air gap is used in vector control systems. It is impossible to create windings for this machine. The basis of the new calculation approach was the Conductivity of Teeth Contours Method, developed at the Electrical Machines Chair of the Moscow Power Engineering Institute (MPEI. Unlike this method, the author used not absolute values, but relative magnitudes of magnetic fluxes. This solution fundamentally improved the method’s capabilities. The relative magnitudes of the magnetic fluxes of the teeth contours do not required the additional consideration for exact structure of magnetic field of tooth and adjacent slots. These structures are identical for all the teeth of the machine and differ only in magnitude. The purpose of the calculations was not traditional harmonic analysis of magnetic induction distribution in air gap of machine, but a refinement of the equations of electric machine model. The vector control researchers used only the cos(θ function as a value of mutual magnetic coupling coefficient between the windings. Results: The author has developed a way to take into account the design of the windings of a real machine by using imaginary measuring winding with the same winding design as a real phase winding. The imaginary winding can be placed in the position of any machine windings. The calculation of the relative magnetic fluxes of this winding helped to estimate the real values of the magnetic coupling coefficients between the windings, and find the correction functions for the model of an idealized

  6. A double-sided linear primary permanent magnet vernier machine.

    Science.gov (United States)

    Du, Yi; Zou, Chunhua; Liu, Xianxing

    2015-01-01

    The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed.

  7. Feasibility study of permanent magnet generator topologies for small-scale wind power application

    Energy Technology Data Exchange (ETDEWEB)

    Rovio, T.

    2010-07-01

    In this work the design of electric generators for use in a 300-Watt wind power plant is explored. These generators must also be suitable for short-series manufacture. There are two foci: the best design methods for these machines and comparison of technical and economical performance of machnines designed with these methods. I explain how the wind turbine affects the generator design process. Easy-to-manufacture structures are selected from each electric machine topology. The design and construction of prototype axial and radial flux machines is studied. A design method for a claw-pole transversal flux machine is introduced. This design method is based on FEM and genetic optimization, without recourse to iron-circuit models. Finally, I compare the predicted performance of the new claw-pole transversal flux generator to axial flux and radial flux generator prototypes is compared

  8. Comparison Between Wind Power Prediction Models Based on Wavelet Decomposition with Least-Squares Support Vector Machine (LS-SVM and Artificial Neural Network (ANN

    Directory of Open Access Journals (Sweden)

    Maria Grazia De Giorgi

    2014-08-01

    Full Text Available A high penetration of wind energy into the electricity market requires a parallel development of efficient wind power forecasting models. Different hybrid forecasting methods were applied to wind power prediction, using historical data and numerical weather predictions (NWP. A comparative study was carried out for the prediction of the power production of a wind farm located in complex terrain. The performances of Least-Squares Support Vector Machine (LS-SVM with Wavelet Decomposition (WD were evaluated at different time horizons and compared to hybrid Artificial Neural Network (ANN-based methods. It is acknowledged that hybrid methods based on LS-SVM with WD mostly outperform other methods. A decomposition of the commonly known root mean square error was beneficial for a better understanding of the origin of the differences between prediction and measurement and to compare the accuracy of the different models. A sensitivity analysis was also carried out in order to underline the impact that each input had in the network training process for ANN. In the case of ANN with the WD technique, the sensitivity analysis was repeated on each component obtained by the decomposition.

  9. Guide to commercially available wind machines

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-03

    Wind Energy Conversion Systems (WECS) commercially available in the United States are described. The terms used to describe these wind systems are defined and their significance discussed. Lists of manufacturers and distributors, subsystem components and suppliers, and references are provided.

  10. Extracting meaning from audio signals - a machine learning approach

    DEFF Research Database (Denmark)

    Larsen, Jan

    2007-01-01

    * Machine learning framework for sound search * Genre classification * Music and audio separation * Wind noise suppression......* Machine learning framework for sound search * Genre classification * Music and audio separation * Wind noise suppression...

  11. McCabe wind energy system

    International Nuclear Information System (INIS)

    Norton, R.; McCabe, F.; MacMichael, G.

    1995-01-01

    A wind machine utilizing novel low-speed air foils and shrouds has been developed and is now undergoing a refinement process. Energy generated by the machine at a variety of wind speeds is significant. Use of the machine to compress air, which can serve a variety of applications, simplifies the total power producing system ranking it economical and practical for use at a variety of locations to fill many energy requirements. (author)

  12. McCabe wind energy system

    Energy Technology Data Exchange (ETDEWEB)

    Norton, R [Wyndmoor (United States); McCabe, F [Levr/Air, Inc., Doylestown (United States); MacMichael, G [Regional Technical College, Galway (Iran, Islamic Republic of)

    1996-12-31

    A wind machine utilizing novel low-speed air foils and shrouds has been developed and is now undergoing a refinement process. Energy generated by the machine at a variety of wind speeds is significant. Use of the machine to compress air, which can serve a variety of applications, simplifies the total power producing system ranking it economical and practical for use at a variety of locations to fill many energy requirements. (author)

  13. McCabe wind energy system

    Energy Technology Data Exchange (ETDEWEB)

    Norton, R. [Wyndmoor (United States); McCabe, F. [Levr/Air, Inc., Doylestown (United States); MacMichael, G. [Regional Technical College, Galway (Iran, Islamic Republic of)

    1995-12-31

    A wind machine utilizing novel low-speed air foils and shrouds has been developed and is now undergoing a refinement process. Energy generated by the machine at a variety of wind speeds is significant. Use of the machine to compress air, which can serve a variety of applications, simplifies the total power producing system ranking it economical and practical for use at a variety of locations to fill many energy requirements. (author)

  14. Effects of an electromagnetic shield and armature teeth on the short-circuit performance of a direct drive superconducting generator for 10 MW wind turbines

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2015-01-01

    reactance. An electromagnetic (EM) shield between the rotor and the stator as well as iron or non-magnetic composite (NMC) armature teeth affects the sub-transient reactance of a superconducting machine so that they play a role in the short-circuit performance of a superconducting wind generator. This paper...

  15. Megawatt wind turbines gaining momentum

    International Nuclear Information System (INIS)

    Oehlenschlaeger, K.; Madsen, B.T.

    1996-01-01

    Through the short history of the modern wind turbine, electric utilities have made it amply clear that they have held a preference for large scale wind turbines over smaller ones, which is why wind turbine builders through the years have made numerous attempts develop such machines - machines that would meet the technical, aesthetic and economic demands that a customer would require. Considerable effort was put into developing such wind turbines in the early 1980s. There was the U.S. Department of Energy's MOD 1-5 program, which ranged up to 3.2 MW, Denmark's Nibe A and B, 630 kW turbine and the 2 MW Tjaereborg machine, Sweden's Naesudden, 3 MW, and Germany's Growian, 3 MW. Most of these were dismal failures, though some did show the potential of MW technology. (au)

  16. Transition of wind power utilization technology in the 20th century; 20 seiki ni okeru furyoku riyo gijutsu no hensen

    Energy Technology Data Exchange (ETDEWEB)

    Ushiyama, I. [Ashikaga Inst. of Tech., Tochigi (Japan)

    2000-04-01

    Windmills are one of the oldest prime movers and have been used for more than 700 years in Europe. The transition from low speed windmills for grain grinding and water pumping to high speed wind turbines for electric power generation had occurred at the end of 19{sup th} century. This paper, at first, reviews the windmill technologies and the researchers before 20th century. Then describes the back ground of how the wind power generator has existed and how the four pioneers developed their wind power generator. The historical developments of windmills to wind turbines in this century are studied focusing mainly on Danish activities. Then, the effort of the development of large wind turbine such as Smith-Putnum's first MW machine in U.S.A. and other mammoth machine concept are introduced. The new concept machines such as Savonius and Darrieus wind turbines in 1920s to 1930s are also explained. Finally, the novel technologies of wind turbine covering larger machines, variable speed generators, special wing sections for wind turbines, theoretical analysis method of wind turbine performance, offshore wind turbines, and wind turbine control technologies are stated. (author)

  17. Power Performance Test Report for the SWIFT Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, I.; Hur, J.

    2012-12-01

    This report summarizes the results of a power performance test that NREL conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the SWIFT is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  18. Agustin de Betancourt’s wind machine for draining marshy ground: analysis of its construction through computer-aided engineering

    Directory of Open Access Journals (Sweden)

    J. I. Rojas-Sola

    2018-04-01

    Full Text Available The objective of this research is to analyze the construction of the wind machine for draining marshy ground designed by Agustin de Betancourt and Molina in 1789. To do this, a static analysis by finite elements method from the threedimensional model obtained with Autodesk Inventor Professional has been performed. The results show that the greatest stresses of the mechanism take place when the main shaft is meshed with the cogwheel, namely the point of contact between the worm screw and cogwheel. However, the maximum displacements and the greatest deformations take place in the blades. In addition, the mechanism is oversized, reaching at no point the tensile strength of the material, confirming the successful construction of this historical invention.

  19. Machine Learning for Wind Turbine Blades Maintenance Management

    Directory of Open Access Journals (Sweden)

    Alfredo Arcos Jiménez

    2017-12-01

    Full Text Available Delamination in Wind Turbine Blades (WTB is a common structural problem that can generate large costs. Delamination is the separation of layers of a composite material, which produces points of stress concentration. These points suffer greater traction and compression forces in working conditions, and they can trigger cracks, and partial or total breakage of the blade. Early detection of delamination is crucial for the prevention of breakages and downtime. The main novelty presented in this paper has been to apply an approach for detecting and diagnosing the delamination WTB. The approach is based on signal processing of guided waves, and multiclass pattern recognition using machine learning. Delamination was induced in the WTB to check the accuracy of the approach. The signal is denoised by wavelet transform. The autoregressive Yule–Walker model is employed for feature extraction, and Akaike’s information criterion method for feature selection. The classifiers are quadratic discriminant analysis, k-nearest neighbors, decision trees, and neural network multilayer perceptron. The confusion matrix is employed to evaluate the classification, especially the receiver operating characteristic analysis by: recall, specificity, precision, and F-score.

  20. New software for improving performance in wind farm operations

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Mark [Ekho for Wind (Canada)

    2011-07-01

    The performance of wind farms depends on multiple field and business systems. This makes operational planning difficult because of so many data being in separate systems, duplication of data and the impossibility of gathering all relevant data together in one place. The aim of this paper is to present a new software, Ekho for Wind, which helps improve performance in wind farm operations by providing features such as high level views, performance analysis, downtime tracking, quality data management and forecast generation. This new software provides operational intelligence which offers incentives for continuous improvement. Ekho for Wind can bring such benefits as maximization of generation, increased lifetime of assets, minimization of costs and increased profitability. This presentation introduced a new software for improving the performance of wind farms and the lifetime of assets, resulting in significant payback.

  1. Directly driven generators for wind power applications

    Energy Technology Data Exchange (ETDEWEB)

    Lampola, P [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Electromechanics

    1996-12-31

    The article deals with an analysis of directly driven, low-speed wind generators. The generators studied were a permanent-magnet synchronous machine and an asynchronous machine. The machines were compared with a typical generator of a wind power plant. The electromagnetic optimization of the machines was done by the finite element method. The rated power of the generators was 500 kW and the rotational speed was 40 rpm. (author)

  2. Directly driven generators for wind power applications

    Energy Technology Data Exchange (ETDEWEB)

    Lampola, P. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Electromechanics

    1995-12-31

    The article deals with an analysis of directly driven, low-speed wind generators. The generators studied were a permanent-magnet synchronous machine and an asynchronous machine. The machines were compared with a typical generator of a wind power plant. The electromagnetic optimization of the machines was done by the finite element method. The rated power of the generators was 500 kW and the rotational speed was 40 rpm. (author)

  3. Commissioning of Theratron phoenix telecobalt machine and its performance assessment

    International Nuclear Information System (INIS)

    Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kumar, K.; Gopi, S.; Rajan, Dharani; Janardhanan

    2002-01-01

    Teletherapy machines like cobalt-60 unit and linear accelerator are extensively used for radiotherapy. Theratron phoenix machines have been installed. A brief report on the performance of this machine is presented

  4. Evaluation of a small-scale wind power plant; Utvaerdering av smaaskaligt vindkraftverk

    Energy Technology Data Exchange (ETDEWEB)

    Arvidsson, Ulf; Hilding, Sten [Elforsk AB, Stockholm (Sweden)

    2001-12-01

    The aim of this work is to evaluate the electrical performance of the 20 kW Pitch Wind turbine. The work was originally intended to focus on evaluating the first machine in a series of three, which should be a machine ready for series production. However, the control system of the machine was not tested and verified so instead a large part of the work has been to check that the electrical system and the control system operates as intended and to adjust and suggest improvements. The design includes a self-regulating variable speed wind turbine coupled to a permanent magnet generator and a converter.

  5. Performance Comparison of Two Topologies Double-Fed Brushless Machine with 36 Slots for Low-Speed Applications

    Directory of Open Access Journals (Sweden)

    Yue Hao

    2014-12-01

    Full Text Available The performances of two topologies of low-speed double-fed brushless machine (DFBM with fractional slot windings are quantitatively compared and analyzed using two-dimensional (2-D finite element method (FEM. To fairly compare the torque capability and power efficiency of different DFBMs, the investigated DFBMs have the same outer diameter, the same axial stack length and the same iron core materials, and some comparison rules are presented. In order to maximize the torque density, several important structure parameters are optimized. The results of this paper reveal the torque density levels and power density levels of two kinds of DFBMs.

  6. AUTOMATIC WINDING GENERATION USING MATRIX REPRESENTATION - ANFRACTUS TOOL 1.0

    Directory of Open Access Journals (Sweden)

    Daoud Ouamara

    2018-02-01

    Full Text Available This paper describes an original approach dealing with AC/DC winding design in electrical machines. A research software called “ANFRACTUS Tool 1.0”, allowing automatic generation of all windings in multi-phases electrical machines, has been developed using the matrix representation. Unlike existent methods, where the aim is to synthesize a winding with higher performances, the proposed method provides the opportunity to choose between all doable windings. The specificity of this approach is based on the fact that it take only the slots, phases and layers number as input parameters. The poles number is not requested to run the generation process. Windings generation by matrix representation may be applied for any number of slots, phases and layers. The software do not deal with the manner that coils are connected but just the emplacement of coils in each slot with its current sense. The waveform and the harmonic spectrum of the total magnetomotive force (MMF are given as result.

  7. Power Performance Verification of a Wind Farm Using the Friedman’s Test

    Science.gov (United States)

    Hernandez, Wilmar; López-Presa, José Luis; Maldonado-Correa, Jorge L.

    2016-01-01

    In this paper, a method of verification of the power performance of a wind farm is presented. This method is based on the Friedman’s test, which is a nonparametric statistical inference technique, and it uses the information that is collected by the SCADA system from the sensors embedded in the wind turbines in order to carry out the power performance verification of a wind farm. Here, the guaranteed power curve of the wind turbines is used as one more wind turbine of the wind farm under assessment, and a multiple comparison method is used to investigate differences between pairs of wind turbines with respect to their power performance. The proposed method says whether the power performance of the specific wind farm under assessment differs significantly from what would be expected, and it also allows wind farm owners to know whether their wind farm has either a perfect power performance or an acceptable power performance. Finally, the power performance verification of an actual wind farm is carried out. The results of the application of the proposed method showed that the power performance of the specific wind farm under assessment was acceptable. PMID:27271628

  8. Power Performance Verification of a Wind Farm Using the Friedman’s Test

    Directory of Open Access Journals (Sweden)

    Wilmar Hernandez

    2016-06-01

    Full Text Available In this paper, a method of verification of the power performance of a wind farm is presented. This method is based on the Friedman’s test, which is a nonparametric statistical inference technique, and it uses the information that is collected by the SCADA system from the sensors embedded in the wind turbines in order to carry out the power performance verification of a wind farm. Here, the guaranteed power curve of the wind turbines is used as one more wind turbine of the wind farm under assessment, and a multiple comparison method is used to investigate differences between pairs of wind turbines with respect to their power performance. The proposed method says whether the power performance of the specific wind farm under assessment differs significantly from what would be expected, and it also allows wind farm owners to know whether their wind farm has either a perfect power performance or an acceptable power performance. Finally, the power performance verification of an actual wind farm is carried out. The results of the application of the proposed method showed that the power performance of the specific wind farm under assessment was acceptable.

  9. Effects of pole flux distribution in a homopolar linear synchronous machine

    Science.gov (United States)

    Balchin, M. J.; Eastham, J. F.; Coles, P. C.

    1994-05-01

    Linear forms of synchronous electrical machine are at present being considered as the propulsion means in high-speed, magnetically levitated (Maglev) ground transportation systems. A homopolar form of machine is considered in which the primary member, which carries both ac and dc windings, is supported on the vehicle. Test results and theoretical predictions are presented for a design of machine intended for driving a 100 passenger vehicle at a top speed of 400 km/h. The layout of the dc magnetic circuit is examined to locate the best position for the dc winding from the point of view of minimum core weight. Measurements of flux build-up under the machine at different operating speeds are given for two types of secondary pole: solid and laminated. The solid pole results, which are confirmed theoretically, show that this form of construction is impractical for high-speed drives. Measured motoring characteristics are presented for a short length of machine which simulates conditions at the leading and trailing ends of the full-sized machine. Combination of the results with those from a cylindrical version of the machine make it possible to infer the performance of the full-sized traction machine. This gives 0.8 pf and 0.9 efficiency at 300 km/h, which is much better than the reported performance of a comparable linear induction motor (0.52 pf and 0.82 efficiency). It is therefore concluded that in any projected high-speed Maglev systems, a linear synchronous machine should be the first choice as the propulsion means.

  10. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Mijatovic, Nenad

    cryostat design, where a concept with 20 W of heat transfer is achieved. Following the setup description, the focus turns to the electromagnetic design of the HTS machine. Particularly, an approach to increase the performance of HTS coils and the influence of the armature reaction to the HTS field winding...... magnetic characteristic with respect to the critical current. I have showed that the potential for the reduction of HTS conductor can be significant, if the coils are placed strategically, whereby the coils wound with BSCCO performed 40% better depending on the placement in the field winding. The 2G coils...... were less sensitive to the placement which made them particularly useful for high magnetic field regions in the eld winding. The second design approach proposed and tested was to use multiple current supplies which allowed each coil to operate close to its critical current. I have demonstrated...

  11. Wind Power Now!

    Science.gov (United States)

    Inglis, David Rittenhouse

    1975-01-01

    The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

  12. Double U-Core Switched Reluctance Machine

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to an electrical machine stator comprising a plurality of stator segments (131,132,133), each segment comprises a first U-core and a second U-core wound with a winding, where the winding being arranged with at least one coil turn, each coil turn comprises a first axial......(s), wherein the first U-core and the second U-core are located adjacent to each other, whereby the winding spans the first and second U-cores. The invention also relates to a SRM machine with a stator mentioned above and a rotor....

  13. Design Considerations of a Transverse Flux Machine for Direct-Drive Wind Turbine Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Husain, Tausif; Hasan, Iftekhar; Sozer, Yilmaz; Husain, Iqbal; Muljadi, Eduard

    2017-01-01

    This paper presents the design considerations of a double-sided transverse flux machine (TFM) for direct-drive wind turbine applications. The TFM has a modular structure with quasi-U stator cores and ring windings. The rotor is constructed with ferrite magnets in a flux-concentrating arrangement to achieve high air gap flux density. The design considerations for this TFM with respect to initial sizing, pole number selection, key design ratios, and pole shaping are presented in this paper. Pole number selection is critical in the design process of a TFM because it affects both the torque density and power factor under fixed magnetic and changing electrical loading. Several key design ratios are introduced to facilitate the design procedure. The effect of pole shaping on back-emf and inductance is also analyzed. These investigations provide guidance toward the required design of a TFM for direct-drive applications. The analyses are carried out using analytical and three-dimensional finite element analysis. A prototype is under construction for experimental verification.

  14. Optimal controller design of a doubly fed induction generator wind turbine system for small signal stability enhancement

    DEFF Research Database (Denmark)

    Yang, Lihui; Yang, Guang-Ya; Xu, Zhao

    2010-01-01

    Multi-objective optimal controller design of a doubly-fed induction generator (DFIG) wind turbine system using differential evolution (DE) is presented. A detailed mathematical model of DFIG wind turbine with a closed-loop vector control system is developed. Based on this, objective functions...... and the constraint with DE, respectively. Eigenvalue analysis and time-domain simulations are performed on a single machine infinite bus system as well as a nine-bus multi-machine system with two DFIG wind turbines to illustrate the control performance of the DFIG wind turbine with the optimised controller...... addressing the steady-state stability and dynamic performance at different operating conditions are implemented to optimise the controller parameters of both the rotor and grid-side converters. A superior 1-constraint method and method of adaptive penalties are applied to handle the multi-objective problem...

  15. Concentrated Windings in Compact Permanent Magnet Synchronous Generators: Managing Efficiency

    Directory of Open Access Journals (Sweden)

    Olivier Barré

    2016-01-01

    Full Text Available In electric power generation, customers want generators with high efficiency. Nowadays, modern turbo-generators have efficiencies greater than 98%. Although this amount should not be obtained for all kind of machines, efficiency will remain one of the main parameters for customer choice. Efficiency is also linked to the life of the machine: the higher the efficiency is, the longer the machine’s lifetime. During the past decade, new forms of energy production have appeared and generators have been developed to fit well into this market. For example, wind generators evolved towards permanent magnet generators having high polarity and running at low speed. Nevertheless, their structure is not fixed. An industrial company has built a prototype of such a generator which uses fractional-slot concentrated-windings (FSCW. This kind of winding is not the structure used by default in such electrical machines. Another field of interest is in autonomous generators which can be used on boats. Even if everyone has in mind large merchant ships, we must not forget smaller ships, such as fishing boats and short-range cruise ships, which spend the most of their time near the coast. This kind of ship does nothave large areas for installing the electric generation or the electric propulsion. It is the reason why, in this article, we focus on the efficiency of machines using fractional-slot concentrated-windings. In many publications which compare performances between distributed and concentrated windings, the result is almost the same. The efficiency of FSCW is not as high as the efficiency associated to the machines which are using distributed windings. Design methods have to be redrawn to integrate, as soon as possible, the loss mitigation in order to provide the best efficiency in power conversion. The following discussion, step by step, introduces the loss mitigation in every part of a machine using FSCW. To close the discussion, a design is produced and it

  16. Axial gap rotating electrical machine

    Science.gov (United States)

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  17. Convective Heat Transfer Coefficients of Automatic Transmission Fluid Jets with Implications for Electric Machine Thermal Management: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin; Moreno, Gilberto

    2015-09-29

    Thermal management for electric machines (motors/ generators) is important as the automotive industry continues to transition to more electrically dominant vehicle propulsion systems. Cooling of the electric machine(s) in some electric vehicle traction drive applications is accomplished by impinging automatic transmission fluid (ATF) jets onto the machine's copper windings. In this study, we provide the results of experiments characterizing the thermal performance of ATF jets on surfaces representative of windings, using Ford's Mercon LV ATF. Experiments were carried out at various ATF temperatures and jet velocities to quantify the influence of these parameters on heat transfer coefficients. Fluid temperatures were varied from 50 degrees C to 90 degrees C to encompass potential operating temperatures within an automotive transaxle environment. The jet nozzle velocities were varied from 0.5 to 10 m/s. The experimental ATF heat transfer coefficient results provided in this report are a useful resource for understanding factors that influence the performance of ATF-based cooling systems for electric machines.

  18. DOE/NASA Lewis large-wind-turbine program

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R.L.

    1982-01-01

    There are several ongoing large wind system development project; ots directed toward meeting the technology requirements for utility applications. First generation tehcnology machines (Mod-0A and Mod-1) and second generation machines (Mod-2) are in opoeration at selected utility sites. Third generation technology machines (Mod-5) are in the design phase and are scheduled for initial operation in 1984 if project funding is continued. An overview of the large wind turbine activities managed by NASA Lewis is provided. These activities include results from the first and second generation field machines (Mod-0A, 01, and -2), the status of the Department of Interior WTS-4 machine for which NASA is responsible for technical management, and the design phase of the third generation wind turbines (Mod-5).

  19. The art and science of rotating field machines design a practical approach

    CERN Document Server

    Ostović, Vlado

    2017-01-01

    This book highlights procedures utilized by the design departments of leading global manufacturers, offering readers essential insights into the electromagnetic and thermal design of rotating field (induction and synchronous) electric machines. Further, it details the physics of the key phenomena involved in the machines’ operation, conducts a thorough analysis and synthesis of polyphase windings, and presents the tools and methods used in the evaluation of winding performance. The book develops and solves the machines’ magnetic circuits, and determines their electromagnetic forces and torques. Special attention is paid to thermal problems in electrical machines, along with fluid flow computations. With a clear emphasis on the practical aspects of electric machine design and synthesis, the author applies his nearly 40 years of professional experience with electric machine manufacturers – both as an employee and consultant – to provide readers with the tools they need to determine fluid flow parameters...

  20. Reduced-Capacity Inrush Current Suppressor Using a Matrix Converter in a Wind Power Generation System with Squirrel-Cage Induction Machines

    Directory of Open Access Journals (Sweden)

    Sho Shibata

    2016-03-01

    Full Text Available This paper describes the reduced capacity of the inrush current suppressor using a matrix converter (MC in a large-capacity wind power generation system (WPGS with two squirrel-cage induction machines (SCIMs. These SCIMs are switched over depending on the wind speed. The input side of the MC is connected to the source in parallel. The output side of the MC is connected in series with the SCIM through matching transformers. The modulation method of the MC used is direct duty ratio pulse width modulation. The reference output voltage of the MC is decided by multiplying the SCIM current with the variable control gain. Therefore, the MC performs as resistors for the inrush current. Digital computer simulation is implemented to confirm the validity and practicability of the proposed inrush current suppressor using PSCAD/EMTDC (power system computer-aided design/electromagnetic transients including DC. Furthermore, the equivalent resistance of the MC is decided by the relationship between the equivalent resistance and the capacity of the MC. Simulation results demonstrate that the proposed inrush current suppressor can suppress the inrush current perfectly.

  1. A new geometrical construction using rounded surfaces proposed for the transverse flux machine for direct drive wind turbine

    DEFF Research Database (Denmark)

    Argeseanu, Alin; Nica, Florin Valentin Traian; Ritchie, Ewen

    2014-01-01

    This paper proposes a new construction for transverse flux machines (TFM) using a rounded surfaces core geometry. The new concept has been developed for TFM with U core geometry. In this case a new analytic design procedure was proposed. The analytic design of the new TFM construction is further ...... proposed concept is more attractive for the direct-drive wind turbine application....

  2. Electric converters of electromagnetic strike machine with capacitor supply

    Science.gov (United States)

    Usanov, K. M.; Volgin, A. V.; Kargin, V. A.; Moiseev, A. P.; Chetverikov, E. A.

    2018-03-01

    The application of pulse linear electromagnetic engines in small power strike machines (energy impact is 0.01...1.0 kJ), where the characteristic mode of rare beats (pulse seismic vibrator, the arch crash device bins bulk materials), is quite effective. At the same time, the technical and economic performance of such machines is largely determined by the ability of the power source to provide a large instantaneous power of the supply pulses in the winding of the linear electromagnetic motor. The use of intermediate energy storage devices in power systems of rare-shock LEME makes it possible to obtain easily large instantaneous powers, forced energy conversion, and increase the performance of the machine. A capacitor power supply of a pulsed source of seismic waves is proposed for the exploration of shallow depths. The sections of the capacitor storage (CS) are connected to the winding of the linear electromagnetic motor by thyristor dischargers, the sequence of activation of which is determined by the control device. The charge of the capacitors to the required voltage is made directly from the battery source, or through the converter from a battery source with a smaller number of batteries.

  3. Prediction of tunnel boring machine performance using machine and rock mass data

    International Nuclear Information System (INIS)

    Dastgir, G.

    2012-01-01

    Performance of the tunnel boring machine and its prediction by different methods has been a hot issue since the first TBM came into being. For the sake of safe and sound transport, improvement of hydro-power, mining, civil and many other tunneling projects that cannot be driven efficiently and economically by conventional drill and blast, TBMs are quite frequently used. TBM parameters and rock mass properties, which heavily influence machine performance, should be estimated or known before choice of TBM-type and start of excavation. By applying linear regression analysis (SPSS19), fuzzy logic tools and a special Math-Lab code on actual field data collected from seven TBM driven tunnels (Hieflau expansion, Queen water tunnel, Vereina, Hemerwald, Maen, Pieve and Varzo tunnel), an attempt was made to provide prediction of rock mass class (RMC), rock fracture class (RFC), penetration rate (PR) and advance rate (AR). For detailed analysis of TBM performance, machine parameters (thrust, machine rpm, torque, power etc.), machine types and specification and rock mass properties (UCS, discontinuity in rock mass, RMC, RFC, RMR, etc.) were analyzed by 3-D surface plotting using statistical software R. Correlations between machine parameters and rock mass properties which effectively influence prediction models, are presented as well. In Hieflau expansion tunnel AR linearly decreases with increase of thrust due to high dependence of machine advance rate upon rock strength. For Hieflau expansion tunnel three types of data (TBM, rock mass and seismic data e.g. amplitude, pseudo velocity etc.) were coupled and simultaneously analyzed by plotting 3-D surfaces. No appreciable correlation between seismic data (Amplitude and Pseudo velocity) and rock mass properties and machine parameters could be found. Tool wear as a function of TBM operational parameters was analyzed which revealed that tool wear is minimum if applied thrust is moderate and that tool wear is high when thrust is

  4. Wind energy utilization: A bibliography

    Science.gov (United States)

    1975-01-01

    Bibliography cites documents published to and including 1974 with abstracts and references, and is indexed by topic, author, organization, title, and keywords. Topics include: Wind Energy Potential and Economic Feasibility, Utilization, Wind Power Plants and Generators, Wind Machines, Wind Data and Properties, Energy Storage, and related topics.

  5. Experimental study of improved HAWT performance in simulated natural wind by an active controlled multi-fan wind tunnel

    Science.gov (United States)

    Toshimitsu, Kazuhiko; Narihara, Takahiko; Kikugawa, Hironori; Akiyoshi, Arata; Kawazu, Yuuya

    2017-04-01

    The effects of turbulent intensity and vortex scale of simulated natural wind on performance of a horizontal axis wind turbine (HAWT) are mainly investigated in this paper. In particular, the unsteadiness and turbulence of wind in Japan are stronger than ones in Europe and North America in general. Hence, Japanese engineers should take account of the velocity unsteadiness of natural wind at installed open-air location to design a higher performance wind turbine. Using the originally designed five wind turbines on the basis of NACA and MEL blades, the dependencies of the wind frequency and vortex scale of the simulated natural wind are presented. As the results, the power coefficient of the newly designed MEL3-type rotor in the simulated natural wind is 130% larger than one in steady wind.

  6. Multi-Pole HTS Generators for Direct Drive Wind Turbines

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Abrahamsen, Asger Bech; Seiler, Eugen

    or the performance of the coated conductor has to improve significantly (by a factor of 10 or more) in order for HTS generators to become feasible in direct drive offshore wind turbines. This price/performance improvement is not unrealistic in the coming decade. Additionally the reliability of such machines...

  7. Effect of machining fluid on the process performance of wire electrical discharge machining of nanocomposite ceramic

    Directory of Open Access Journals (Sweden)

    Zhang Chengmao

    2015-01-01

    Full Text Available Wire electric discharge machining (WEDM promise to be effective and economical techniques for the production of tools and parts from conducting ceramic blanks. However, the manufacturing of nanocomposite ceramics blanks with these processes is a long and costly process. This paper presents a new process of machining nanocomposite ceramics using WEDM. WEDM uses water based emulsion, polyvinyl alcohol and distilled water as the machining fluid. Machining fluid is a primary factor that affects the material removal rate and surface quality of WEDM. The effects of emulsion concentration, polyvinyl alcohol concentration and distilled water of the machining fluid on the process performance have been investigated.

  8. Permanent magnet motor drives with switched stator windings

    Energy Technology Data Exchange (ETDEWEB)

    Nipp, E.

    1999-06-01

    interruptions when changing the configuration. The durations of these zero torque periods and their avoidance have been examined thoroughly in this thesis by means of simulations and experiments on a specially designed and built 5OkW test machine. It was found that semiconductor winding switches should be used to avoid noticeable jerks. A novel method is suggested on how to perform winding re-configurations so that torque interruptions are avoided. The principle is based on temporary operation of the machine with its windings in asymmetric configurations which is analyzed analytically and validated by experiments. It is proven that successive winding switching is an appropriate means to entirely omit torque interruptions. Finally, the application of PM motors with switched stator windings in a subway propulsion drive is briefly considered. Different aspects of their feasibility are taken into consideration and the great potential of such drives is pointed out.

  9. Statistical and Machine Learning Models to Predict Programming Performance

    OpenAIRE

    Bergin, Susan

    2006-01-01

    This thesis details a longitudinal study on factors that influence introductory programming success and on the development of machine learning models to predict incoming student performance. Although numerous studies have developed models to predict programming success, the models struggled to achieve high accuracy in predicting the likely performance of incoming students. Our approach overcomes this by providing a machine learning technique, using a set of three significant...

  10. Compound induction electric rotating machine

    Energy Technology Data Exchange (ETDEWEB)

    Decesare, D

    1987-07-28

    The present invention generally relates to dynamo-electric machines cabable of operating in a generator mode or in a motor mode and more specifically, to increased efficiency compound interaction AC and/or DC dynamo-electric machines. This patent describes such a machine having a distributed armature winding in a cylindrical rotor wound to form axial and substantially radial winding portions and including permanent and/or electromagnets to couple magnetic flux into the peripheral or circumferential surface of the rotor, and to provide interaction between a magnetic field formed beyond the rotor axial surfaces and the rotor to thereby enhance the total induction of flux into the rotor for improved, more efficient operation. 28 figs.,

  11. Reliability assessment of Wind turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2015-01-01

    Wind turbines can be considered as structures that are in between civil engineering structures and machines since they consist of structural components and many electrical and machine components together with a control system. Further, a wind turbine is not a one-of-a-kind structure...... but manufactured in series production based on many component tests, some prototype tests and zeroseries wind turbines. These characteristics influence the reliability assessment where focus in this paper is on the structural components. Levelized Cost Of Energy is very important for wind energy, especially when...... comparing to other energy sources. Therefore much focus is on cost reductions and improved reliability both for offshore and onshore wind turbines. The wind turbine components should be designed to have sufficient reliability level with respect to both extreme and fatigue loads but also not be too costly...

  12. Performance characteristics of aerodynamically optimum turbines for wind energy generators

    Science.gov (United States)

    Rohrbach, C.; Worobel, R.

    1975-01-01

    This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

  13. Downstream wind flow path diversion and its effects on the performance of vertical axis wind turbine

    International Nuclear Information System (INIS)

    Maganhar, A.L.

    2015-01-01

    In the present experimental study efforts have been made to analysis path diversion effect of downstream wind flow on performance of vertical axis wind turbine (VAWT). For the blockage of downstream wind flow path at various linear displaced positions, a normal erected flat wall, semi-circular and cylindrical shapes were tested for path diverting geometries. Performance of VAWT in terms of improved rotor speed up to 45% was achieved. (author)

  14. Cogenerative Performance of a Wind − Gas Turbine − Organic Rankine Cycle Integrated System for Offshore Applications

    DEFF Research Database (Denmark)

    Bianchi, Michele; Branchini, Lisa; De Pascale, Andrea

    2016-01-01

    Gas Turbines (GT) are widely used for power generationin offshore oil and gas facilities, due to their high reliability,compactness and dynamic response capabilities. Small heavyduty and aeroderivative units in multiple arrangements aretypically used to offer larger load flexibility......, but limitedefficiency of such machines is the main drawback. A solutionto enhance the system performance, also in Combined Heat andPower (CHP) arrangement, is the implementation of OrganicRankine Cycle (ORC) systems at the bottom of the gas turbines.Moreover, the resulting GT-ORC combined cycle could befurther...... a 10MW offshorewind farm and three gas turbines rated for 16:5MW, eachone coupled with an 4:5MW ORC module. The ORC mainparameters are observed under different wind power fluctuations.Due to the non-programmable availability of wind and powerdemand, the part-load and dynamic characteristics...

  15. Wind energy technology : from the past to the future; 20 seiki ni okeru furyoku riyo gijutsu no henkan. Furyoku hatsuden : kako kara mirai e

    Energy Technology Data Exchange (ETDEWEB)

    Ushiyama, I. [Ashikaga Institute of Technology, Tochigi (Japan)

    2000-01-20

    Windmills are one of the oldest prime movers and have been used for more than 700 years in Europe. The transition from low speed windmills for grain grinding and water pumping to high speed wind turbines for electric power generation had occurred at first, reviews the windmill technologies and the researchers before 20{sup th} century. Then describes the back ground of how the wind power generator has existed and how the four pioneers developed their wind power generator. The historical developments of windmills to wind turbines in this century are studied focusing mainly on Danish activities. Then, the effort of the development of large wind turbine such as Smith-Putnum's first MW machine in U.S.A. and other mammoth machine concept are introduced. The new concept machines such as Savonius and Darrieus wind turbines in 1920s to 1930s are also explained. Finally, the novel technologies of wind turbine covering larger machines, variable speed generators, special wing sections for wind turbines, theoretical analysis method of wind turbine performance, offshore wind turbines, and wind turbine control technologies are stated. (author)

  16. Performance Analysis of Abrasive Waterjet Machining Process at Low Pressure

    Science.gov (United States)

    Murugan, M.; Gebremariam, MA; Hamedon, Z.; Azhari, A.

    2018-03-01

    Normally, a commercial waterjet cutting machine can generate water pressure up to 600 MPa. This range of pressure is used to machine a wide variety of materials. Hence, the price of waterjet cutting machine is expensive. Therefore, there is a need to develop a low cost waterjet machine in order to make the technology more accessible for the masses. Due to its low cost, such machines may only be able to generate water pressure at a much reduced rate. The present study attempts to investigate the performance of abrasive water jet machining process at low cutting pressure using self-developed low cost waterjet machine. It aims to study the feasibility of machining various materials at low pressure which later can aid in further development of an effective low cost water jet machine. A total of three different materials were machined at a low pressure of 34 MPa. The materials are mild steel, aluminium alloy 6061 and plastics Delrin®. Furthermore, a traverse rate was varied between 1 to 3 mm/min. The study on cutting performance at low pressure for different materials was conducted in terms of depth penetration, kerf taper ratio and surface roughness. It was found that all samples were able to be machined at low cutting pressure with varied qualities. Also, the depth of penetration decreases with an increase in the traverse rate. Meanwhile, the surface roughness and kerf taper ratio increase with an increase in the traverse rate. It can be concluded that a low cost waterjet machine with a much reduced rate of water pressure can be successfully used for machining certain materials with acceptable qualities.

  17. Impact of Wind Power Plants with Full Converter Wind Turbines on Power System Small-Signal Stability

    DEFF Research Database (Denmark)

    Knüppel, Thyge; Nygaard Nielsen, Jørgen; Dixon, Andrew

    Wind power is being developed in power systems all around the world, and already today wind power covers more than 20 % of the electricity consumption in some countries. As the size of each wind power plant (WPP) increases and as the levels of penetration reaches certain magnitudes, the inclusion...... of the dynamic properties of the WPPs in the power system stability studies become important. The work presented in this report deal with the impact of WPPs based on full converter wind turbines (WTs) on the power system small-signal rotor angle stability. During small disturbances in the power system, the rotor...... speed of the synchronous machines will eventually return to its steady state if the power system is small-signal stable. The dynamic properties of a WPP are fundamentally dierent from those of a synchronous machine, and the interaction of WPPs with the synchronous machines in power system oscillations...

  18. Combined preliminary–detailed design of wind turbines

    Directory of Open Access Journals (Sweden)

    P. Bortolotti

    2016-05-01

    Full Text Available This paper is concerned with the holistic optimization of wind turbines. A multi-disciplinary optimization procedure is presented that marries the overall sizing of the machine in terms of rotor diameter and tower height (often termed “preliminary design” with the detailed sizing of its aerodynamic and structural components. The proposed combined preliminary–detailed approach sizes the overall machine while taking into full account the subtle and complicated couplings that arise due to the mutual effects of aerodynamic and structural choices. Since controls play a central role in dictating performance and loads, control laws are also updated accordingly during optimization. As part of the approach, rotor and tower are sized simultaneously, even in this case capturing the mutual effects of one component over the other due to the tip clearance constraint. The procedure, here driven by detailed models of the cost of energy, results in a complete aero-structural design of the machine, including its associated control laws. The proposed methods are tested on the redesign of two wind turbines, a 2.2 MW onshore machine and a large 10 MW offshore one. In both cases, the optimization leads to significant changes with respect to the initial baseline configurations, with noticeable reductions in the cost of energy. The novel procedures are also exercised on the design of low-induction rotors for both considered wind turbines, showing that they are typically not competitive with conventional high-efficiency rotors.

  19. Wind energy systems solutions for power quality and stabilization

    CERN Document Server

    Ali, Mohd Hasan

    2012-01-01

    Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases--and wind energy is a free, renewable resource. However, the induction machines commonly used as wind generators have stability problems similar to the transient stability of synchronous machines. To minimize power, frequency, and voltage fluctuations caused by network faults or random wind speed variations, control mechanisms are necessary. Wind Energy Systems: Solutions for Power Quality and Stabilization clearly explains how to solve stability and power quality issues of wind generator systems. Covering

  20. Energy saving work of frequency controlled induction cage machine

    Energy Technology Data Exchange (ETDEWEB)

    Gnacinski, P. [Gdynia Maritime University, Department of Ship Electrical Power Engineering, Morska Str. 8, 81-225 Gdynia (Poland)]. E-mail: piotrg@am.gdynia.pl

    2007-03-15

    Energy saving work, understood as lowering the supply voltage when load torque is much less than rated, is one way of reducing power losses in an induction cage machine working with a variable load. Reduction in power losses also affects the thermal properties of an induction machine because the energy saving work allows the temperature rise of the windings to decrease. Thanks to a lower temperature of the windings, the same load torque can be carried by a machine of less rated power. The ability of energy saving work to reduce the temperature of windings depends on the thermal properties of an induction machine, which are different in the case of a machine with foreign ventilation and its own ventilation. This paper deals with the thermal effect of energy saving work on a frequency controlled induction cage machine. A comparison of the properties of a machine with its own and outside ventilation is presented. The results of the investigations are shown for a 3 kW induction cage machine with the two previously mentioned ways of ventilation: one provided with a fan placed on a shaft and the other provided with a fan driven by an auxiliary motor.

  1. Energy saving work of frequency controlled induction cage machine

    International Nuclear Information System (INIS)

    Gnacinski, P.

    2007-01-01

    Energy saving work, understood as lowering the supply voltage when load torque is much less than rated, is one way of reducing power losses in an induction cage machine working with a variable load. Reduction in power losses also affects the thermal properties of an induction machine because the energy saving work allows the temperature rise of the windings to decrease. Thanks to a lower temperature of the windings, the same load torque can be carried by a machine of less rated power. The ability of energy saving work to reduce the temperature of windings depends on the thermal properties of an induction machine, which are different in the case of a machine with foreign ventilation and its own ventilation. This paper deals with the thermal effect of energy saving work on a frequency controlled induction cage machine. A comparison of the properties of a machine with its own and outside ventilation is presented. The results of the investigations are shown for a 3 kW induction cage machine with the two previously mentioned ways of ventilation: one provided with a fan placed on a shaft and the other provided with a fan driven by an auxiliary motor

  2. Influence of electrical resistivity and machining parameters on electrical discharge machining performance of engineering ceramics.

    Science.gov (United States)

    Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

    2014-01-01

    Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge

  3. European wind turbine testing procedure developments. Task 1: Measurement method to verify wind turbine performance characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, R.; Friis Pedersen, T.; Dunbabin, P.; Antoniou, I.; Frandsen, S.; Klug, H.; Albers, A.; Lee, W.K.

    2001-01-01

    There is currently significant standardisation work ongoing in the context of wind farm energy yield warranty assessment and wind turbine power performance testing. A standards maintenance team is revising the current IEC (EN) 61400-12 Ed 1 standard for wind turbine power performance testing. The standard is being divided into four documents. Two of them are drafted for evaluation and verification of complete wind farms and of individual wind turbines within wind farms. This document, and the project it describes, has been designed to help provide a solid technical foundation for this revised standard. The work was wide ranging and addressed 'grey' areas of knowledge, regarding existing methodologies or to carry out basic research in support of fundamentally new procedures. The work has given rise to recommendations in all areas of the work, including site calibration procedures, nacelle anemometry, multi-variate regression analysis and density normalisation. (au)

  4. Wind Power Utilization Guide.

    Science.gov (United States)

    1981-09-01

    The expres- sions for the rotor torque for a Darrieus machine can be found in Reference 4.16. The Darrieus wind turbine offers the following... turbine generators, wind -driven turbines , power conditioning, wind power, energy conservation, windmills, economic ana \\sis. 20 ABS 1"ACT (Conti,on... turbines , power conditioning requirements, siting requirements, and the economics of wind power under different conditions. Three examples are given to

  5. A robust combination approach for short-term wind speed forecasting and analysis – Combination of the ARIMA (Autoregressive Integrated Moving Average), ELM (Extreme Learning Machine), SVM (Support Vector Machine) and LSSVM (Least Square SVM) forecasts using a GPR (Gaussian Process Regression) model

    International Nuclear Information System (INIS)

    Wang, Jianzhou; Hu, Jianming

    2015-01-01

    With the increasing importance of wind power as a component of power systems, the problems induced by the stochastic and intermittent nature of wind speed have compelled system operators and researchers to search for more reliable techniques to forecast wind speed. This paper proposes a combination model for probabilistic short-term wind speed forecasting. In this proposed hybrid approach, EWT (Empirical Wavelet Transform) is employed to extract meaningful information from a wind speed series by designing an appropriate wavelet filter bank. The GPR (Gaussian Process Regression) model is utilized to combine independent forecasts generated by various forecasting engines (ARIMA (Autoregressive Integrated Moving Average), ELM (Extreme Learning Machine), SVM (Support Vector Machine) and LSSVM (Least Square SVM)) in a nonlinear way rather than the commonly used linear way. The proposed approach provides more probabilistic information for wind speed predictions besides improving the forecasting accuracy for single-value predictions. The effectiveness of the proposed approach is demonstrated with wind speed data from two wind farms in China. The results indicate that the individual forecasting engines do not consistently forecast short-term wind speed for the two sites, and the proposed combination method can generate a more reliable and accurate forecast. - Highlights: • The proposed approach can make probabilistic modeling for wind speed series. • The proposed approach adapts to the time-varying characteristic of the wind speed. • The hybrid approach can extract the meaningful components from the wind speed series. • The proposed method can generate adaptive, reliable and more accurate forecasting results. • The proposed model combines four independent forecasting engines in a nonlinear way.

  6. Driving and control strategies in alternative current machines of permanent magnet with non-sinusoidal flux; Estrategias de acionamento e controle em maquinas CA de ima permanente com fluxo nao senoidal

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Jose Roberto Boffino de Almeida

    1997-07-01

    The aim of this work is to study and analyze the torque performance of brush less machines with non-sinusoidal distributed magnetic fluxes. The machine type considered is a surface mount permanent magnet brush less machine. Three mathematical models for the machine are considered: the per stator phase, the vectorial and the linear second order speed-voltage models. Machines with different stator windings are compared including the permanent magnet synchronous machines with sinusoidal distributed stator windings. The torque outputs of these machines are obtained considering two kinds of open loop driving systems: one with a six-pulse waveform and other with a sinusoidal waveform. Finally, a vectorial control is proposed for the non-sinusoidal machines. The torque ripple as well the overall performance of non-sinusoidal machines with vectorial control is compared to that of sinusoidal machines. (author)

  7. Theoretical design study of the MSFC wind-wheel turbine

    Science.gov (United States)

    Frost, W.; Kessel, P. A.

    1982-01-01

    A wind wheel turbine (WWT) is studied. Evaluation of the probable performance, possible practical applications, and economic viability as compared to other conventional wind energy systems is discussed. The WWT apparatus is essentially a bladed wheel which is directly exposed to the wind on the upper half and exposed to wind through multiple ducting on the lower half. The multiple ducts consist of a forward duct (front concentrator) and two side ducts (side concentrators). The forced rotation of the wheel is then converted to power through appropriate subsystems. Test results on two simple models, a paper model and a stainless steel model, are reported. Measured values of power coefficients over wind speeds ranging from 4 to 16 m/s are given. An analytical model of a four bladed wheel is also developed. Overall design features of the wind turbine are evaluated and discussed. Turbine sizing is specified for a 5 and 25 kW machine. Suggested improvements to the original design to increase performance and performance predictions for an improved WWT design are given.

  8. European wind turbine testing procedure developments. Task 1: Measurement method to verify wind turbine performance characteristics

    DEFF Research Database (Denmark)

    Hunter, R.; Friis Pedersen, Troels; Dunbabin, P.

    2001-01-01

    There is currently significant standardisation work ongoing in the context of wind farm energy yield warranty assessment and wind turbine power performance testing. A standards maintenance team is revising the current IEC (EN) 61400-12 Ed 1 standard forwind turbine power performance testing....... The standard is being divided into four documents. Two of them are drafted for evaluation and verification of complete wind farms and of individual wind turbines within wind farms. This document, and the project itdescribes, has been designed to help provide a solid technical foundation for this revised...... standard. The work was wide ranging and addressed 'grey' areas of knowledge, regarding existing methodologies or to carry out basic research in support offundamentally new procedures. The work has given rise to recommendations in all areas of the work, including site calibration procedures, nacelle...

  9. Multiobjective Design of Turbo Injection Mode for Axial Flux Motor in Plastic Injection Molding Machine by Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Jian-Long Kuo

    2015-01-01

    Full Text Available This paper proposes a turbo injection mode (TIM for an axial flux motor to apply onto injection molding machine. Since the injection molding machine requires different speed and force parameters setting when finishing a complete injection process. The interleaved winding structure in the motor provides two different injection levels to provide enough injection forces. Two wye-wye windings are designed to switch two control modes conveniently. Wye-wye configuration is used to switch two force levels for the motor. When only one set of wye-winding is energized, field weakening function is achieved. Both of the torque and speed increase under field weakening operation. To achieve two control objectives for torque and speed of the motor, fuzzy based multiple performance characteristics index (MPCI with particle swarm optimization (PSO is used to find out the multiobjective optimal design solution. Both of the torque and speed are expected to be maximal at the same time. Three control factors are selected as studied factors: winding diameter, winding type, and air-gap. Experimental results show that both of the torque and speed increase under the optimal condition. This will provide enough large torque and speed to perform the turbo injection mode in injection process for the injection molding machine.

  10. Wind energy conversion 1994. Proceedings

    International Nuclear Information System (INIS)

    Elliot, G.

    1995-01-01

    At the British Wind Energy Association's 16th Annual Conference, held in Stirling, over 60 high quality papers were presented, including a session devoted to 'Wind Energy in Scotland'. Under the Non Fossil Fuel Obligation (NFFO) wind energy has experienced rapid growth in England and Wales and with Scotland now having its own 'Scottish Renewables Obligation' (SRO) the opportunity to tap one of Europe's most important renewable energy resources now exists. The main contemporary issues concerning wind farming today, namely technical, social, economic and environmental were examined in the Geoff Pontin Memorial Lecture, which focused on these aspects in the context of grid integrated wind energy development. The remaining conference themes included machine development, aerodynamics and control, small machines, fatigue and dynamics, public attitudes, noise emissions, electrical integration, resource measurement, and standards, safety and planning. (author)

  11. Reference Manual for the System Advisor Model's Wind Power Performance Model

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, J.; Jorgenson, J.; Gilman, P.; Ferguson, T.

    2014-08-01

    This manual describes the National Renewable Energy Laboratory's System Advisor Model (SAM) wind power performance model. The model calculates the hourly electrical output of a single wind turbine or of a wind farm. The wind power performance model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs. In SAM, the performance model can be coupled to one of the financial models to calculate economic metrics for residential, commercial, or utility-scale wind projects. This manual describes the algorithms used by the wind power performance model, which is available in the SAM user interface and as part of the SAM Simulation Core (SSC) library, and is intended to supplement the user documentation that comes with the software.

  12. Performance evaluation of stand alone hybrid PV-wind generator

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H. [Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia); Yahaya, M. S. [Faculty of Engineering Technology, Universiti Teknikal Malaysia Melaka (UTeM), Hang Tuah Jaya, 76100 Melaka (Malaysia)

    2015-05-15

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  13. Performance evaluation of stand alone hybrid PV-wind generator

    Science.gov (United States)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-05-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand.

  14. Performance evaluation of stand alone hybrid PV-wind generator

    International Nuclear Information System (INIS)

    Nasir, M. N. M.; Saharuddin, N. Z.; Sulaima, M. F.; Jali, Mohd Hafiz; Bukhari, W. M.; Bohari, Z. H.; Yahaya, M. S.

    2015-01-01

    This paper presents the performance evaluation of standalone hybrid system on Photovoltaic (PV)-Wind generator at Faculty of Electrical Engineering (FKE), UTeM. The hybrid PV-Wind in UTeM system is combining wind turbine system with the solar system and the energy capacity of this hybrid system can generate up to charge the battery and supply the LED street lighting load. The purpose of this project is to evaluate the performance of PV-Wind hybrid generator. Solar radiation meter has been used to measure the solar radiation and anemometer has been used to measure the wind speed. The effectiveness of the PV-Wind system is based on the various data that has been collected and compared between them. The result shows that hybrid system has greater reliability. Based on the solar result, the correlation coefficient shows strong relationship between the two variables of radiation and current. The reading output current followed by fluctuate of solar radiation. However, the correlation coefficient is shows moderate relationship between the two variables of wind speed and voltage. Hence, the wind turbine system in FKE show does not operate consistently to produce energy source for this hybrid system compare to PV system. When the wind system does not fully operate due to inconsistent energy source, the other system which is PV will operate and supply the load for equilibrate the extra load demand

  15. On the Fatigue Analysis of Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, Herbert J.

    1999-06-01

    Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. Operational experiences with these large rotating machines indicated that their components (primarily blades and blade joints) were failing at unexpectedly high rates, which led the wind turbine community to develop fatigue analysis capabilities for wind turbines. Our ability to analyze the fatigue behavior of wind turbine components has matured to the point that the prediction of service lifetime is becoming an essential part of the design process. In this review paper, I summarize the technology and describe the ''best practices'' for the fatigue analysis of a wind turbine component. The paper focuses on U.S. technology, but cites European references that provide important insights into the fatigue analysis of wind turbines.

  16. Volumetric scans of wind turbine wakes performed with three simultaneous wind LiDARs under different atmospheric stability regimes

    International Nuclear Information System (INIS)

    Iungo, Giacomo Valerio; Porté-Agel, Fernando

    2014-01-01

    Aerodynamic optimization of wind farm layout is a crucial task to reduce wake effects on downstream wind turbines, thus to maximize wind power harvesting. However, downstream evolution and recovery of wind turbine wakes are strongly affected by the characteristics of the incoming atmospheric boundary layer (ABL) flow, such as wind shear and turbulence intensity, which are in turn affected by the ABL thermal stability. In order to characterize the downstream evolution of wakes produced by full-scale wind turbines under different atmospheric conditions, wind velocity measurements were performed with three wind LiDARs. The volumetric scans are performed by continuously sweeping azimuthal and elevation angles of the LiDARs in order to cover a 3D volume that includes the wind turbine wake. The minimum wake velocity deficit is then evaluated as a function of the downstream location for different atmospheric conditions. It is observed that the ABL thermal stability has a significant effect on the wake evolution, and the wake recovers faster under convective conditions

  17. Performance of the CORDEX regional climate models in simulating offshore wind and wind potential

    Science.gov (United States)

    Kulkarni, Sumeet; Deo, M. C.; Ghosh, Subimal

    2018-03-01

    This study is oriented towards quantification of the skill addition by regional climate models (RCMs) in the parent general circulation models (GCMs) while simulating wind speed and wind potential with particular reference to the Indian offshore region. To arrive at a suitable reference dataset, the performance of wind outputs from three different reanalysis datasets is evaluated. The comparison across the RCMs and their corresponding parent GCMs is done on the basis of annual/seasonal wind statistics, intermodel bias, wind climatology, and classes of wind potential. It was observed that while the RCMs could simulate spatial variability of winds, well for certain subregions, they generally failed to replicate the overall spatial pattern, especially in monsoon and winter. Various causes of biases in RCMs were determined by assessing corresponding maps of wind vectors, surface temperature, and sea-level pressure. The results highlight the necessity to carefully assess the RCM-yielded winds before using them for sensitive applications such as coastal vulnerability and hazard assessment. A supplementary outcome of this study is in form of wind potential atlas, based on spatial distribution of wind classes. This could be beneficial in suitably identifying viable subregions for developing offshore wind farms by intercomparing both the RCM and GCM outcomes. It is encouraging that most of the RCMs and GCMs indicate that around 70% of the Indian offshore locations in monsoon would experience mean wind potential greater than 200 W/m2.

  18. Power from the Wind

    Science.gov (United States)

    Roman, Harry T.

    2004-01-01

    Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

  19. Towards a virtual platform for aerodynamic design, performance assessment and optimization of horizontal axis wind turbines

    OpenAIRE

    Martínez Valdivieso, Daniel

    2017-01-01

    This thesis focuses on the study and improvement of the techniques involved on a virtual platform for the simulation of the Aerodynamics of Horizontal Axis Wind Turbines, with the ultimate objective of making Wind Energy more competitive. Navier-Stokes equations govern Aerodynamics, which is an unresolved and very active field of research due to the current inability to capture the relevant the scales both in time and space for nowadays industrial-size machines (with rotors over 100 m...

  20. Virtual machine performance benchmarking.

    Science.gov (United States)

    Langer, Steve G; French, Todd

    2011-10-01

    The attractions of virtual computing are many: reduced costs, reduced resources and simplified maintenance. Any one of these would be compelling for a medical imaging professional attempting to support a complex practice on limited resources in an era of ever tightened reimbursement. In particular, the ability to run multiple operating systems optimized for different tasks (computational image processing on Linux versus office tasks on Microsoft operating systems) on a single physical machine is compelling. However, there are also potential drawbacks. High performance requirements need to be carefully considered if they are to be executed in an environment where the running software has to execute through multiple layers of device drivers before reaching the real disk or network interface. Our lab has attempted to gain insight into the impact of virtualization on performance by benchmarking the following metrics on both physical and virtual platforms: local memory and disk bandwidth, network bandwidth, and integer and floating point performance. The virtual performance metrics are compared to baseline performance on "bare metal." The results are complex, and indeed somewhat surprising.

  1. FY1999 technological development of wind power generation systems for islands. Development of wind power generation systems in islands; 1999 nendo ritoyo furyoku hatsuden system nado gijutsu kaihatsu. Rito ni okeru furyoku hatsuden system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    With an objective of developing wind power generation systems that suit small to medium size islands in Japan, conceptual design was made on a 100-kW class wind mill to satisfy such requirements as no need of large heavy machines, and gust resisting performance. Investigations were performed on sites suitable for demonstration tests thereof. This paper reports the achievements in fiscal 1999. In investigating the site location feasibilities, which took small to medium size islands in Okinawa Prefecture as the discussion objects, environmental investigation, wind condition forecast and investigation, and system linkage investigation were carried out, whereas one point each in three islands were extracted as the promising sites. The system discussion and design called for wind velocity resistance of 80 m/s, system linkage percentage of 40% at maximum, power generation cost of 20 yen per kWh, design life of 20 years, constructability of requiring no large heavy machines, and operation mode of diesel hybrid use. Along with these specifications, conceptual design was performed on the system constituting elements, such as wind mill blades, generators, electric power control devices, and towers. In the blade aerodynamic test, wind tunnel tests were executed by using three types of blade wings. Sample blades were fabricated for the preparation of blade material tests. (NEDO)

  2. Aerodynamic performance prediction of Darrieus-type wind turbines

    Directory of Open Access Journals (Sweden)

    Ion NILĂ

    2010-06-01

    Full Text Available The prediction of Darrieus wind turbine aerodynamic performances provides the necessarydesign and operational data base related to the wind potential. In this sense it provides the type ofturbine suitable to the area where it is to be installed. Two calculation methods are analyzed for arotor with straight blades. The first one is a global method that allows an assessment of the turbinenominal power by a brief calculation. This method leads to an overestimation of performances. Thesecond is the calculation method of the gust factor and momentum which deals with the pale as beingcomposed of different elements that don’t influence each other. This method, developed based on thetheory of the turbine blades, leads to values close to the statistical data obtained experimentally. Thevalues obtained by the calculation method of gust factor - momentum led to the concept of a Darrieusturbine, which will be tested for different wind values in the INCAS subsonic wind tunnel.

  3. Superconducting magnetic systems and electrical machines

    International Nuclear Information System (INIS)

    Glebov, I.A.

    1975-01-01

    The use of superconductors for magnets and electrical machines attracts close attention of designers and scientists. A description is given of an ongoing research program to create superconductive magnetic systems, commutator motors, homopolar machines, topological generators and turbogenerators with superconductive field windings. All the machines are tentative experimental models and serve as a basis for further developments

  4. Generation of electricity by wind power

    Energy Technology Data Exchange (ETDEWEB)

    Golding, E W

    1976-01-01

    Information on wind power is presented concerning the history of windmills; estimation of the energy obtainable from the wind; wind characteristics and distribution; wind power sites; wind surveys; wind flow over hills; measurement of wind velocity; wind structure and its determination; wind data and energy estimation; testing of wind driven ac generators; wind-driven machines; propeller type windmills; plants for isolated premises and small communities; economy of wind power generation; construction costs for large wind-driven generators; relationship of wind power to other power sources; research and development; and international cooperation.

  5. An SVM-based solution for fault detection in wind turbines.

    Science.gov (United States)

    Santos, Pedro; Villa, Luisa F; Reñones, Aníbal; Bustillo, Andres; Maudes, Jesús

    2015-03-09

    Research into fault diagnosis in machines with a wide range of variable loads and speeds, such as wind turbines, is of great industrial interest. Analysis of the power signals emitted by wind turbines for the diagnosis of mechanical faults in their mechanical transmission chain is insufficient. A successful diagnosis requires the inclusion of accelerometers to evaluate vibrations. This work presents a multi-sensory system for fault diagnosis in wind turbines, combined with a data-mining solution for the classification of the operational state of the turbine. The selected sensors are accelerometers, in which vibration signals are processed using angular resampling techniques and electrical, torque and speed measurements. Support vector machines (SVMs) are selected for the classification task, including two traditional and two promising new kernels. This multi-sensory system has been validated on a test-bed that simulates the real conditions of wind turbines with two fault typologies: misalignment and imbalance. Comparison of SVM performance with the results of artificial neural networks (ANNs) shows that linear kernel SVM outperforms other kernels and ANNs in terms of accuracy, training and tuning times. The suitability and superior performance of linear SVM is also experimentally analyzed, to conclude that this data acquisition technique generates linearly separable datasets.

  6. An SVM-Based Solution for Fault Detection in Wind Turbines

    Directory of Open Access Journals (Sweden)

    Pedro Santos

    2015-03-01

    Full Text Available Research into fault diagnosis in machines with a wide range of variable loads and speeds, such as wind turbines, is of great industrial interest. Analysis of the power signals emitted by wind turbines for the diagnosis of mechanical faults in their mechanical transmission chain is insufficient. A successful diagnosis requires the inclusion of accelerometers to evaluate vibrations. This work presents a multi-sensory system for fault diagnosis in wind turbines, combined with a data-mining solution for the classification of the operational state of the turbine. The selected sensors are accelerometers, in which vibration signals are processed using angular resampling techniques and electrical, torque and speed measurements. Support vector machines (SVMs are selected for the classification task, including two traditional and two promising new kernels. This multi-sensory system has been validated on a test-bed that simulates the real conditions of wind turbines with two fault typologies: misalignment and imbalance. Comparison of SVM performance with the results of artificial neural networks (ANNs shows that linear kernel SVM outperforms other kernels and ANNs in terms of accuracy, training and tuning times. The suitability and superior performance of linear SVM is also experimentally analyzed, to conclude that this data acquisition technique generates linearly separable datasets.

  7. Equivalent model of a dually-fed machine for electric drive control systems

    Science.gov (United States)

    Ostrovlyanchik, I. Yu; Popolzin, I. Yu

    2018-05-01

    The article shows that the mathematical model of a dually-fed machine is complicated because of the presence of a controlled voltage source in the rotor circuit. As a method of obtaining a mathematical model, the method of a generalized two-phase electric machine is applied and a rotating orthogonal coordinate system is chosen that is associated with the representing vector of a stator current. In the chosen coordinate system in the operator form the differential equations of electric equilibrium for the windings of the generalized machine (the Kirchhoff equation) are written together with the expression for the moment, which determines the electromechanical energy transformation in the machine. Equations are transformed so that they connect the currents of the windings, that determine the moment of the machine, and the voltages on these windings. The structural diagram of the machine is assigned to the written equations. Based on the written equations and accepted assumptions, expressions were obtained for the balancing the EMF of windings, and on the basis of these expressions an equivalent mathematical model of a dually-fed machine is proposed, convenient for use in electric drive control systems.

  8. Wave and Wind Model Performance Metrics Tools

    Science.gov (United States)

    Choi, J. K.; Wang, D. W.

    2016-02-01

    Continual improvements and upgrades of Navy ocean wave and wind models are essential to the assurance of battlespace environment predictability of ocean surface wave and surf conditions in support of Naval global operations. Thus, constant verification and validation of model performance is equally essential to assure the progress of model developments and maintain confidence in the predictions. Global and regional scale model evaluations may require large areas and long periods of time. For observational data to compare against, altimeter winds and waves along the tracks from past and current operational satellites as well as moored/drifting buoys can be used for global and regional coverage. Using data and model runs in previous trials such as the planned experiment, the Dynamics of the Adriatic in Real Time (DART), we demonstrated the use of accumulated altimeter wind and wave data over several years to obtain an objective evaluation of the performance the SWAN (Simulating Waves Nearshore) model running in the Adriatic Sea. The assessment provided detailed performance of wind and wave models by using cell-averaged statistical variables maps with spatial statistics including slope, correlation, and scatter index to summarize model performance. Such a methodology is easily generalized to other regions and at global scales. Operational technology currently used by subject matter experts evaluating the Navy Coastal Ocean Model and the Hybrid Coordinate Ocean Model can be expanded to evaluate wave and wind models using tools developed for ArcMAP, a GIS application developed by ESRI. Recent inclusion of altimeter and buoy data into a format through the Naval Oceanographic Office's (NAVOCEANO) quality control system and the netCDF standards applicable to all model output makes it possible for the fusion of these data and direct model verification. Also, procedures were developed for the accumulation of match-ups of modelled and observed parameters to form a data base

  9. Orthogonal Analysis Based Performance Optimization for Vertical Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Lei Song

    2016-01-01

    Full Text Available Geometrical shape of a vertical axis wind turbine (VAWT is composed of multiple structural parameters. Since there are interactions among the structural parameters, traditional research approaches, which usually focus on one parameter at a time, cannot obtain performance of the wind turbine accurately. In order to exploit overall effect of a novel VAWT, we firstly use a single parameter optimization method to obtain optimal values of the structural parameters, respectively, by Computational Fluid Dynamics (CFD method; based on the results, we then use an orthogonal analysis method to investigate the influence of interactions of the structural parameters on performance of the wind turbine and to obtain optimization combination of the structural parameters considering the interactions. Results of analysis of variance indicate that interactions among the structural parameters have influence on performance of the wind turbine, and optimization results based on orthogonal analysis have higher wind energy utilization than that of traditional research approaches.

  10. Factors Affecting Slot Machine Performance in an Electronic Gaming Machine Facility

    OpenAIRE

    Etienne Provencal; David L. St-Pierre

    2017-01-01

    A facility exploiting only electronic gambling machines (EGMs) opened in 2007 in Quebec City, Canada under the name of Salons de Jeux du Québec (SdjQ). This facility is one of the first worldwide to rely on that business model. This paper models the performance of such EGMs. The interest from a managerial point of view is to identify the variables that can be controlled or influenced so that a comprehensive model can help improve the overall performance of the business. The EGM individual per...

  11. Tunnel Boring Machine Performance Study. Final Report

    Science.gov (United States)

    1984-06-01

    Full face tunnel boring machine "TBM" performance during the excavation of 6 tunnels in sedimentary rock is considered in terms of utilization, penetration rates and cutter wear. The construction records are analyzed and the results are used to inves...

  12. Electromagnetic Comparison of 3-, 5- and 7-phases Permanent-Magnet Synchronous Machines : Mild Hybrid Traction Application

    Directory of Open Access Journals (Sweden)

    D. Ouamara

    2016-09-01

    Full Text Available Authors compare the electromagnetic performances of three multi-phases permanent-magnet (PM synchronous machines (PMSM for Mild Hybridtraction application. This comparison was made using two-dimensional (2-D numerical simulations in transient magnetic with eddy-current reaction field in the PMs. The best machine was determined using an energetic analysis (i.e., losses, torque and efficiency according specifications. In this study, the non-overlapping winding with double layer (i.e. all teeth wound type was used. The winding synthesis is based on the "Star of slots" method as well as the Fourier series decomposition of the magnetomotive force (MMF.

  13. Agustin de Betancourt’s Wind Machine for Draining Marshy Ground: Approach to Its Geometric Modeling with Autodesk Inventor Professional

    Directory of Open Access Journals (Sweden)

    José Ignacio Rojas-Sola

    2016-12-01

    Full Text Available The present study shows the process followed in making the three-dimensional model and geometric documentation of a historical invention of the renowned Spanish engineer Agustin de Betancourt y Molina, which forms part of his rich legacy. Specifically, this was a wind machine for draining marshy ground, designed in 1789. The present research relies on the computer-aided design (CAD techniques using Autodesk Inventor Professional software, based on the scant information provided by the only two drawings of the machine, making it necessary to propose a number of dimensional and geometric hypotheses as well as a series of movement restrictions (degrees of freedom, to arrive at a consistent design. The results offer a functional design for this historic invention.

  14. Comparative analysis of partial imaging performance parameters of home and imported X-ray machines

    International Nuclear Information System (INIS)

    Cao Yunxi; Wang Xianyun; Liu Huiqin; Guo Yongxin

    2002-01-01

    Objective: To compare and analyze the performance indexes and the imaging quality of the home and imported X-ray machines through testing their partial imaging performance parameters. Methods: By separate sampling from 10 home and 10 imported X-ray machines, the parameters including tube current, time of exposure, machine total exposure, and repeatability were tested, and the imaging performance was evaluated according to the national standard. Results: All the performance indexes met the standard of GB4505-84. The first sampling tests showed the maximum changing coefficient of imaging performance repeatability of the home X-ray machines was Δmax1 = 0.025, while that of the imported X-ray machine was Δmax1 = 0.016. In the second sampling tests, the maximum changing coefficients of the two were Δmax2 = 0.048 and Δmax2 = 0.022, respectively. Conclusion: The 2 years' follow-up tests indicate that there is no significant difference between the above-mentioned parameters of the elaborately adjusted home X-ray machines and imported ones, but the home X-ray machines are no better than the imported X-ray machines in stability and consistency

  15. Effect of high wind conditions on AHX performance for PFBR

    International Nuclear Information System (INIS)

    Goyal, P.; Datta, Anu; Verma, Vishnu; Singh, R.K.

    2013-05-01

    In case of normal shut down or station blackout condition the core decay heat is removed by Safety Grade Decay Heat Removal System (SGDHRS) in PFBR. The Prototype Fast Breeder Reactor (PFBR) is under construction at Kalpakkam. SGDHRS remove decay heat from the core and dissipate it into the environment with the help of Air Heat Exchanger (AHX). SGDHRS consists of four redundant numbers of totally independent circuits capable of removing decay heat from the hot pool through natural convection in the primary and intermediate sodium sides as well as in the air side. Each circuit consists of a sodium to sodium heat exchanger (DHX) and a sodium to AHX connected to intermediate sodium circuit, AHX is located at a higher elevation compared to DHX. AHX is serpentine type finned tube compact heat exchanger with sodium in the tube side and air flowing over finned tubes. A tall stack provides the driving force for the natural convection of air flow through the AHX, when the dampers are opened. The AHX is placed outside of Reactor Control Building (RCB), on the roof of Steam Generator Building. Due to the presence of nearby buildings around the stack, the AHX performance under high wind condition may be affected. A CFD simulation using CFD-ACE+ code has been carried in which effect of high wind condition and nearby building on AHX performance have been studied. For high wind condition various orientation of wind movement was considered for parametric studies. AHX performance for all the cases were compared with the results that obtained for the absence of nearby buildings. A comparative table was prepared to understand how the AHX performance is effected with the high wind condition for various direction and with the presence of nearby building. It was observed that AHX performance is influenced by high wind conditions in most of the cases for with and without presence of nearby building. Hence to ensure the optimal performance of the AHX under high wind conditions its

  16. Development of arctic wind technology

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H.; Marjaniemi, M.; Antikainen, P. [VTT Energy, Espoo (Finland)

    1998-10-01

    The climatic conditions of Lapland set special technical requirements for wind power production. The most difficult problem regarding wind power production in arctic regions is the build-up of hard and rime ice on structures of the machine

  17. Motion Performance and Mooring System of a Floating Offshore Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    Jing Zhao; Liang Zhang; Haitao Wu

    2012-01-01

    The development of offshore wind farms was originally carried out in shallow water areas with fixed (seabed mounted) structures.However,countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas.The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform.This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine (FOWT) system.The wind turbine was modeled as a wind block with a certain thrust coefficient,and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software.The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined.The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

  18. Motion performance and mooring system of a floating offshore wind turbine

    Science.gov (United States)

    Zhao, Jing; Zhang, Liang; Wu, Haitao

    2012-09-01

    The development of offshore wind farms was originally carried out in shallow water areas with fixed (seabed mounted) structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine (FOWT) system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

  19. Influence of Rare Earth Element Supply on Future Offshore Wind Turbine Generators

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Abrahamsen, Asger Bech; Henriksen, Matthew Lee

    2011-01-01

    electrical machines. Such machines are utilized in applications such as electric cars, and wind turbines. This paper will examine the rare earth supply issue, in order to comment on its relevance to the wind turbine industry. The wind turbine topologies which are currently being used are compared...

  20. Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

    Science.gov (United States)

    Baidak, Y.; Smyk, V.

    2017-08-01

    Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

  1. A Machine LearningFramework to Forecast Wave Conditions

    Science.gov (United States)

    Zhang, Y.; James, S. C.; O'Donncha, F.

    2017-12-01

    Recently, significant effort has been undertaken to quantify and extract wave energy because it is renewable, environmental friendly, abundant, and often close to population centers. However, a major challenge is the ability to accurately and quickly predict energy production, especially across a 48-hour cycle. Accurate forecasting of wave conditions is a challenging undertaking that typically involves solving the spectral action-balance equation on a discretized grid with high spatial resolution. The nature of the computations typically demands high-performance computing infrastructure. Using a case-study site at Monterey Bay, California, a machine learning framework was trained to replicate numerically simulated wave conditions at a fraction of the typical computational cost. Specifically, the physics-based Simulating WAves Nearshore (SWAN) model, driven by measured wave conditions, nowcast ocean currents, and wind data, was used to generate training data for machine learning algorithms. The model was run between April 1st, 2013 and May 31st, 2017 generating forecasts at three-hour intervals yielding 11,078 distinct model outputs. SWAN-generated fields of 3,104 wave heights and a characteristic period could be replicated through simple matrix multiplications using the mapping matrices from machine learning algorithms. In fact, wave-height RMSEs from the machine learning algorithms (9 cm) were less than those for the SWAN model-verification exercise where those simulations were compared to buoy wave data within the model domain (>40 cm). The validated machine learning approach, which acts as an accurate surrogate for the SWAN model, can now be used to perform real-time forecasts of wave conditions for the next 48 hours using available forecasted boundary wave conditions, ocean currents, and winds. This solution has obvious applications to wave-energy generation as accurate wave conditions can be forecasted with over a three-order-of-magnitude reduction in

  2. Machine integrated gearbox for electrical vehicles

    NARCIS (Netherlands)

    Gerrits, T.; Wijnands, C.G.E.; Paulides, J.J.H.; Duarte, J.L.; Lomonova, E.A.

    2014-01-01

    The speed range that can be obtained with an electric machine is initially limited due to the finite supply voltage of the inverter. A winding reconfiguration method named dynamic machine operation is presented, capable of increasing the speed range and speed ratio by altering the configuration of

  3. Financial analysis of wind power projects; Analisis financiero de proyectos eolicos de generacion electrica

    Energy Technology Data Exchange (ETDEWEB)

    Juanico, Luis E; Bergallo, Juan E [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche

    1999-07-01

    In this work a financial assessment of the economic competitiveness of wind power projects in Argentina compared with other no CO{sub 2} emission sources, such as nuclear, was developed. Argentina has a market driven electrical grid system, and no greenhouse gas emissions penalty taxes, together with a very low natural gas cost and a sustained nuclear development program. For the financial analysis an average wind velocity source of 8 m/s, on several wind farms (from 2 machines to 60) built with new technology wind generators (750 kilowatts power, 900 dollar/kilowatt cost) operating over 20 years, was considered. The leveled cost obtained is decreasing while the number of machines is increasing, from 0,130 dollar/kilowatt-hour to 0,090 dollar/kilowatts-hour. This poor performance can be partially explained considering the higher interest rates in the argentine financial market (15%) than the ones in developed countries.

  4. Comparative Performance Analysis of Machine Learning Techniques for Software Bug Detection

    OpenAIRE

    Saiqa Aleem; Luiz Fernando Capretz; Faheem Ahmed

    2015-01-01

    Machine learning techniques can be used to analyse data from different perspectives and enable developers to retrieve useful information. Machine learning techniques are proven to be useful in terms of software bug prediction. In this paper, a comparative performance analysis of different machine learning techniques is explored f or software bug prediction on public available data sets. Results showed most of the mac ...

  5. LQR Feedback Control Development for Wind Turbines Featuring a Digital Fluid Power Transmission System

    DEFF Research Database (Denmark)

    Pedersen, Niels Henrik; Johansen, Per; Andersen, Torben O.

    2016-01-01

    with a DFP motor, which has been combined with the NREL 5-MW reference wind turbine model. A classical variable speed control strategy for wind speeds below rated is proposed for the turbine, where the pump displacement is fixed and the digital motor displacement is varied for pressure control. The digital...... for such digital systems are complicated by its non-smooth behavior. In this paper a control design approach for a digital displacement machine® is proposed and a performance analysis of a wind turbine using a DFP transmission is presented. The performance evaluation is based on a dynamic model of the transmission...... invariant model. Using full-field flow wind profiles as input, the design approach and control performance is verified by simulation in the dynamic model of the wind turbine featuring the DFP transmission. Additionally, the performance is compared to that of the conventional NREL reference turbine...

  6. Development of a representative model of a wind turbine in order to study the installation of several machines on a wind park; Developpement d'un modele representatif d'une eolienne afin d'etudier l'implantation de plusieurs machines sur un parc eolien

    Energy Technology Data Exchange (ETDEWEB)

    Jourieh, M

    2007-12-15

    This thesis is devoted to the study of aerodynamics in wind turbines. It is divided into two main parts, one is experimental, and the other deals with modelling and numerical simulation. The velocity field downstream from a three-bladed wind turbine with a horizontal axis is explored in the wind tunnel at ENSAM-Paris. Two measurement techniques are used: hot wire anemometry and Particle Image Velocimetry (PIV). Experimental work gives a clear idea of the structure of the near wake and provides useful data to validate the numerical simulations and the hybrid models which are studied in this thesis. In the work concerning numerical simulation, two hybrid models are defined and implemented: a model of actuator disc and a model of actuator cylinder, coupled with a simulation based on the numerical resolution of the Navier-Stokes equations. These models are validated by the power of the wind turbine and on the velocity field in the near wake of the rotor. The numerical results are compared with the experimental data resulting from the tests carried out by the NREL for NREL phase II and VI cases. The experimental and numerical velocity fields are also compared in the wake of a wind turbine Rutland 503. In both validation cases, power and wake, the experimental data are in accordance with the results provided by the hybrid models. After this validation, the interaction between several wind turbines is studied and quantified. The tested hybrid models are also used to study the interaction between identical wind turbines placed one behind the other. The obtained results highlight the effect of spacing between the machines as well as the effect of free stream velocity. (author)

  7. RELIABILITY OF MACHINE ELEMENTS IN WIND TURBINES

    Directory of Open Access Journals (Sweden)

    Willi GRUENDER

    2010-06-01

    Full Text Available Worldwide electrical energy production generated by wind turbines grows at a rate of 30 percent. This doubles the total production every three years. At the same time the power of individual stations goes up by 20 percent annually. Whereas today the towers, rotors and drive trains have to handle 5 MW, in about six to eight years they might produce up to fifteen MW. As a consequence, enormous pressure is put on the wind turbine manufacturers, the component suppliers and the operators. And because prototype and field testing is limited by its expense, the design of new turbines demands thorough analysis and simulation. Looking at the critical components of a wind turbine this paper describes advanced design tools which help to anticipate failures, but also assists in optimizing reliability and service life. Development of the software tools has been supported by research activities in many universities.

  8. Efficiency of lung ventilation for people performing wind instruments.

    Science.gov (United States)

    Brzęk, Anna; Famuła, Anna; Kowalczyk, Anna; Plinta, Ryszard

    Wind instruments musicians are particularly prone to excessive respiratory efforts. Prolonged wind instruments performing may lead to changes in respiratory tracts and thus to respiratory muscles overload. It may result in decreasing lung tissue pliability and, as a consequence, in emphysema. Aim of the research has been to describe basic spirometric parameters for wind players and causes of potential changes. Slow and forced spirometry with the use of Micro Lab Viasys (Micro Medical, Great Britain) was conducted on 31 wind musicians (group A). A survey concerning playing time and frequency, weight of instruments, and education on diaphragmatic breathing was conducted. The control group included 34 healthy persons at similar age (group B). The results were statistically described using Excel and Statistica programmes. The respiratory parameters were within the range of physiological norms and forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) exceeded in both groups the values of 100%. Forced vital capacity and expiratory vital capacity (EVC) values were significantly lower in the group of musicians than in the control group (p wind instrument. Spirometric parameters relative to standards may prove a good respiratory capacity. Peak expiratory flow (PEF) and FEV1 may indicate that a proper technique of respiration during performance was acquired. The length of time when performing wind instrument may influence parameters of dynamic spirometry. Med Pr 2016;67(4):427-433. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  9. IMPER: Characterization of the wind field over a large wind turbine rotor - final report; Improved performance

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt Paulsen, U.; Wagner, R.

    2012-01-15

    A modern wind turbine rotor with a contemporary rotor size would easily with the tips penetrate the air between 116 m and 30 m and herby experience effects of different wind. With current rules on power performance measurements such as IEC 61400-121 the reference wind speed is measured at hub height, an oversimplification of the wind energy power over the rotor disk area is carried out. The project comprised a number of innovative and coordinated measurements on a full scale turbine with remote sensing technology and simulations on a 500 kW wind turbine for the effects of wind field characterization. The objective with the present report is to give a short overview of the different experiments carried out and results obtained within the final phase of this project. (Author)

  10. Wind Energy Systems.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    During the 1920s and 1930s, millions of wind energy systems were used on farms and other locations far from utility lines. However, with passage of the Rural Electrification Act in 1939, cheap electricity was brought to rural areas. After that, the use of wind machines dramatically declined. Recently, the rapid rise in fuel prices has led to a…

  11. Apparatus for cooling an electric machine

    Science.gov (United States)

    Palafox, Pepe; Gerstler, William Dwight; Shen, Xiaochun; El-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Salasoo, Lembit

    2013-07-16

    Provided is an apparatus, for example, for use with a rotating electric machine, that includes a housing. The housing can include a housing main portion and a housing end portion. The housing main portion can be configured to be disposed proximal to a body portion of a stator section of an electric machine. The housing main portion can define a main fluid channel that is configured to conduct fluid therethrough. The housing end portion can receive fluid from said main fluid channel and direct fluid into contact with a winding end portion of a conductive winding of the stator section.

  12. Modeling of the wind power plant using software DIgSILENT Power factory

    International Nuclear Information System (INIS)

    Mladenovski, Ljubisha; Iliev, Atanas; Fushtikj, Vangel

    2004-01-01

    This paper presents a method for creating a model of the wind power plant NORDEX N-60 in the DIgSILENT Power factory software. At the beginning, the characteristics of the wind power plant and the used software are shortly described. The next step is modeling the part of the power system where the wind power plant will be connected to the grid The modeling of the turbine part and the generator part of the wind power plant is made with blocks, which are part of the machine block of the composite model. Finally, the results obtained from performed practically oriented simulations are presented in graphical form. Design of the model of the wind power plant NORDEX N-60 was performed at the Faculty of Electrical Engineering, at the University of Rostock, Germany, as a part of the DYSIMAC project. (Author)

  13. A Thermal Performance Analysis and Comparison of Fiber Coils with the D-CYL Winding and QAD Winding Methods

    Directory of Open Access Journals (Sweden)

    Xuyou Li

    2016-06-01

    Full Text Available The thermal performance under variable temperature conditions of fiber coils with double-cylinder (D-CYL and quadrupolar (QAD winding methods is comparatively analyzed. Simulation by the finite element method (FEM is done to calculate the temperature distribution and the thermal-induced phase shift errors in the fiber coils. Simulation results reveal that D-CYL fiber coil itself has fragile performance when it experiences an axially asymmetrical temperature gradient. However, the axial fragility performance could be improved when the D-CYL coil meshes with a heat-off spool. Through further simulations we find that once the D-CYL coil is provided with an axially symmetrical temperature environment, the thermal performance of fiber coils with the D-CYL winding method is better than that with the QAD winding method under the same variable temperature conditions. This valuable discovery is verified by two experiments. The D-CYL winding method is thus promising to overcome the temperature fragility of interferometric fiber optic gyroscopes (IFOGs.

  14. Steady-State Characteristics Analysis of Hybrid-Excited Flux-Switching Machines with Identical Iron Laminations

    Directory of Open Access Journals (Sweden)

    Gan Zhang

    2015-11-01

    Full Text Available Since the air-gap field of flux-switching permanent magnet (FSPM machines is difficult to regulate as it is produced by the stator-magnets alone, a type of hybrid-excited flux-switching (HEFS machine is obtained by reducing the magnet length of an original FSPM machine and introducing a set of field windings into the saved space. In this paper, the steady-state characteristics, especially for the loaded performances of four prototyped HEFS machines, namely, PM-top, PM-middle-1, PM-middle-2, and PM-bottom, are comprehensively compared and evaluated based on both 2D and 3D finite element analysis. Also, the influences of PM materials including ferrite and NdFeB, respectively, on the characteristics of HEFS machines are covered. Particularly, the impacts of magnet movement in the corresponding slot on flux-regulating performances are studied in depth. The best overall performances employing NdFeB can be obtained when magnets are located near the air-gap. The FEA predictions are validated by experimental measurements on corresponding machine prototypes.

  15. Wind Tunnel and Hover Performance Test Results for Multicopter UAS Vehicles

    Science.gov (United States)

    Russell, Carl R.; Jung, Jaewoo; Willink, Gina; Glasner, Brett

    2016-01-01

    There is currently a lack of published data for the performance of multicopter unmanned aircraft system (UAS) vehicles, such as quadcopters and octocopters, often referred to collectively as drones. With the rapidly increasing popularity of multicopter UAS, there is interest in better characterizing the performance of this type of aircraft. By studying the performance of currently available vehicles, it will be possible to develop models for vehicles at this scale that can accurately predict performance and model trajectories. This paper describes a wind tunnel test that was recently performed in the U.S. Army's 7- by 10-ft Wind Tunnel at NASA Ames Research Center. During this wind tunnel entry, five multicopter UAS vehicles were tested to determine forces and moments as well as electrical power as a function of wind speed, rotor speed, and vehicle attitude. The test is described here in detail, and a selection of the key results from the test is presented.

  16. Superconducting Wind Turbine Generators

    Directory of Open Access Journals (Sweden)

    Yunying Pan

    2016-08-01

    Full Text Available Wind energy is well known as a renewable energy because its clean and less polluted characteristic, which is the foundation of development modern wind electricity. To find more efficient wind turbine is the focus of scientists around the world. Compared from conventional wind turbines, superconducting wind turbine generators have advantages at zero resistance, smaller size and lighter weight. Superconducting wind turbine will inevitably become the main trends in this area. This paper intends to introduce the basic concept and principle of superconductivity, and compare form traditional wind turbine to obtain superiority, then to summary three proposed machine concept.While superconductivity have difficulty  in modern technology and we also have proposed some challenges in achieving superconducting wind turbine finally.

  17. Oscillatory Stability and Eigenvalue Sensitivity Analysis of A DFIG Wind Turbine System

    DEFF Research Database (Denmark)

    Yang, Lihui; Xu, Zhao; Østergaard, Jacob

    2011-01-01

    This paper focuses on modeling and oscillatory stability analysis of a wind turbine with doubly fed induction generator (DFIG). A detailed mathematical model of DFIG wind turbine with vector-control loops is developed, based on which the loci of the system Jacobian's eigenvalues have been analyzed......, showing that, without appropriate controller tuning a Hopf bifurcation can occur in such a system due to various factors, such as wind speed. Subsequently, eigenvalue sensitivity with respect to machine and control parameters is performed to assess their impacts on system stability. Moreover, the Hopf...

  18. Scope and prospects of re-engineering and retrofitting wind farms in India

    International Nuclear Information System (INIS)

    Rajsekhar, B.; Van Hulle, F.J.L.

    2001-09-01

    The paper starts with a brief analysis of the characteristics of the Indian wind energy programmes while enumerating the developments that have taken place so far. In view of the large scope for renewable energy based power generation and in order to boost the present uprise of the wind farm development, the authors investigate the possibilities that lay in re-engineering of existing wind farms. Existing wind farm entrepreneurs are showing interest to improve the performance of their wind farms. New initiatives are suggested addressing the involved technical and commercial concerns of both the state-run utility (the principal customer of wind generated electricity) and wind farm entrepreneur to spur development of economically competitive wind-power plants In addition, inferences are drawn from a recently conducted detailed case study at a 5 year old large wind farm in Muppandal area. The study involved conducting detailed WAsP based analysis based on remote land use and land cover details interfacing with GIS. In addition, detailed site investigations were conducted to assess the health of the machines and the adequacy of the power evacuation facility together with the analysis of the machine down times. The paper highlights the benefits that can be expected from such undertakings for several parties both in India and in EU. The paper finally outlines the possible business opportunities and economic benefits that exist for retrofitting and re-engineering in the country, which has over 700 individually designed wind farms. 2 refs

  19. Systems Performance Analyses of Alaska Wind-Diesel Projects; Kotzebue, Alaska (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.

    2009-04-01

    This fact sheet summarizes a systems performance analysis of the wind-diesel project in Kotzebue, Alaska. Data provided for this project include wind turbine output, average wind speed, average net capacity factor, and optimal net capacity factor based on Alaska Energy Authority wind data, estimated fuel savings, and wind system availability.

  20. A comparison of regression algorithms for wind speed forecasting at Alexander Bay

    CSIR Research Space (South Africa)

    Botha, Nicolene

    2016-12-01

    Full Text Available to forecast 1 to 24 hours ahead, in hourly intervals. Predictions are performed on a wind speed time series with three machine learning regression algorithms, namely support vector regression, ordinary least squares and Bayesian ridge regression. The resulting...

  1. Assessing the representativeness of wind data for wind turbine site evaluation

    Science.gov (United States)

    Renne, D. S.; Corotis, R. B.

    1982-01-01

    Once potential wind turbine sites (either for single installations or clusters) are identified through siting procedures, actual evaluation of the sites must commence. This evaluation is needed to obtain estimates of wind turbine performance and to identify hazards to the machine from the turbulence component of the atmosphere. These estimates allow for more detailed project planning and for preliminary financing arrangements to be secured. The site evaluation process can occur in two stages: (1) utilizing existing nearby data, and (2) establishing and monitoring an onsite measurement program. Since step (2) requires a period of at least 1 yr or more from the time a potential site has been identified, step (1) is often an essential stage in the preliminary evaluation process. Both the methods that have been developed and the unknowns that still exist in assessing the representativeness of available data to a nearby wind turbine site are discussed. How the assessment of the representativeness of available data can be used to develop a more effective onsite meteorological measurement program is also discussed.

  2. Fabrication and Performance Evaluation of a Thevetia Nut Cracking Machine

    Directory of Open Access Journals (Sweden)

    M. M. Odewole

    2015-06-01

    Full Text Available Thevetia seed contains about 64 percent of non-edible oil in its oily kernel and this oil can be used for various purposes such as biofuel and bio-oil; making of paints, insecticides, cosmetics, lubricants and cooling oil in electrical transformers. The cakes obtained after oil extraction are incorporated on the field as manure. In order to get quality oil kernels from the hard nuts, there is need to properly crack them; this process of cracking is still a great challenge. As result of the aforementioned problem, this work focused on the design, fabrication and performance evaluation of a thevetia nut cracking machine. The machine works based on the principle of attrition force. Some of the parts designed for were diameter of shaft (13 mm solid shaft and length of belt (A55, power required to operate the machine (2.5 hp, speed of operation (9.14 m/s and the appropriate dimension of angle iron bar of 45 mm × 45 mm × 3 mm was used for the structural support. The fabrication was done systematically followed by the performance evaluation of the machine. The result of the overall cracking efficiency and throughput capacity of the machine were evaluated to be 96.65 % and 510 g⁄min respectively.

  3. Standardizing the performance evaluation of short-term wind prediction models

    DEFF Research Database (Denmark)

    Madsen, Henrik; Pinson, Pierre; Kariniotakis, G.

    2005-01-01

    Short-term wind power prediction is a primary requirement for efficient large-scale integration of wind generation in power systems and electricity markets. The choice of an appropriate prediction model among the numerous available models is not trivial, and has to be based on an objective...... evaluation of model performance. This paper proposes a standardized protocol for the evaluation of short-term wind-poser preciction systems. A number of reference prediction models are also described, and their use for performance comparison is analysed. The use of the protocol is demonstrated using results...... from both on-shore and off-shore wind forms. The work was developed in the frame of the Anemos project (EU R&D project) where the protocol has been used to evaluate more than 10 prediction systems....

  4. Wind power in Denmark technology, policies and results

    International Nuclear Information System (INIS)

    Dannemand Andersen, Per

    1998-11-01

    The Association of Danish Electricity Utilities has estimated the total electricity production from wind turbines in 1997 as 1932 GWh: 384 GWh from utility-owned turbines and 1548 GWh from privately owned turbines. This equals 6% of total electricity consumption in Denmark. Corrected to a 'normal wind year' this equals 6.6% of Denmark's annual electricity consumption. The wind energy index in 1997 was 91%. According to the Danish Association of Electricity Utilities, 4784 turbines with a capacity of 1129 MW were connected to the grid at the end of 1997. 534 turbines and 287 MW were added in 1997, the largest figure ever. These are net figures and included dismantled machines. The actual sales of turbines is a bit higher, reflecting the fact that not all machines sold in 1997 were installed that year. New machines are usually 500 kW, 600 kW and 750 kW. No 1500 kW machines have as yet been installed on a commercial basis in Denmark. (au)

  5. Effects of wind application on thermal perception and self-paced performance

    NARCIS (Netherlands)

    Teunissen, L.P.J.; Haan, A. de; Koning, J.J. de; Daanen, H.A.M.

    2013-01-01

    Physiological and perceptual effects of wind cooling are often intertwined and have scarcely been studied in self-paced exercise. Therefore, we aimed to investigate (1) the independent perceptual effect of wind cooling and its impact on performance and (2) the responses to temporary wind cooling

  6. Short-term wind power prediction based on LSSVM–GSA model

    International Nuclear Information System (INIS)

    Yuan, Xiaohui; Chen, Chen; Yuan, Yanbin; Huang, Yuehua; Tan, Qingxiong

    2015-01-01

    Highlights: • A hybrid model is developed for short-term wind power prediction. • The model is based on LSSVM and gravitational search algorithm. • Gravitational search algorithm is used to optimize parameters of LSSVM. • Effect of different kernel function of LSSVM on wind power prediction is discussed. • Comparative studies show that prediction accuracy of wind power is improved. - Abstract: Wind power forecasting can improve the economical and technical integration of wind energy into the existing electricity grid. Due to its intermittency and randomness, it is hard to forecast wind power accurately. For the purpose of utilizing wind power to the utmost extent, it is very important to make an accurate prediction of the output power of a wind farm under the premise of guaranteeing the security and the stability of the operation of the power system. In this paper, a hybrid model (LSSVM–GSA) based on the least squares support vector machine (LSSVM) and gravitational search algorithm (GSA) is proposed to forecast the short-term wind power. As the kernel function and the related parameters of the LSSVM have a great influence on the performance of the prediction model, the paper establishes LSSVM model based on different kernel functions for short-term wind power prediction. And then an optimal kernel function is determined and the parameters of the LSSVM model are optimized by using GSA. Compared with the Back Propagation (BP) neural network and support vector machine (SVM) model, the simulation results show that the hybrid LSSVM–GSA model based on exponential radial basis kernel function and GSA has higher accuracy for short-term wind power prediction. Therefore, the proposed LSSVM–GSA is a better model for short-term wind power prediction

  7. Comparison of 10 MW superconducting generator topologies for direct-drive wind turbines

    DEFF Research Database (Denmark)

    Liu, Dong; Polinder, Henk; Abrahamsen, Asger Bech

    2015-01-01

    Large wind turbines of 10 MW or higher power levels are desirable for reducing the cost of energy of offshore wind power conversion. Conventional wind generator systems will be costly if scaled up to 10 MW due to rather large size and weight. Direct drive superconducting generators have been...... magnetic field excitation allows for lightweight non-magnetic composite materials for machine cores instead of iron. A topology would probably not be a good option for an offshore wind turbine generator if it demands a far more expensive active material cost than others, even if it has other advantages...... proposed to address the problem with generator size, because the electrical machines with superconducting windings are capable of achieving a higher torque density of an electrical machine. However, the topology to be adopted for superconducting wind generators has not yet been settled, since the high...

  8. Experimental investigation on performance of crossflow wind turbine as effect of blades number

    Science.gov (United States)

    Kurniawati, Diniar Mungil; Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi

    2018-02-01

    Urban living is one of the areas with large electrical power consumption that requires a power supply that is more than rural areas. The number of multi-storey buildings such as offices, hotels and several other buildings that caused electricity power consumption in urban living is very high. Therefore, energy alternative is needed to replace the electricity power consumption from government. One of the utilization of renewable energy in accordance with these conditions is the installation of wind turbines. One type of wind turbine that is now widely studied is a crossflow wind turbines. Crossflow wind turbine is one of vertical axis wind turbine which has good self starting at low wind speed condition. Therefore, the turbine design parameter is necessary to know in order to improve turbine performance. One of wind turbine performance parameter is blades number. The main purpose of this research to investigate the effect of blades number on crossflow wind turbine performance. The design of turbine was 0.4 × 0.4 m2 tested by experimental method with configuration on three kinds of blades number were 8,16 and 20. The turbine investigated at low wind speed on 2 - 5 m/s. The result showed that best performance on 16 blade number.

  9. Performance comparison of control schemes for variable-speed wind turbines

    Science.gov (United States)

    Bottasso, C. L.; Croce, A.; Savini, B.

    2007-07-01

    We analyze the performance of different control schemes when applied to the regulation problem of a variable-speed representative wind turbine. In particular, we formulate and compare a wind-scheduled PID, a LQR controller and a novel adaptive non-linear model predictive controller, equipped with observers of the tower states and wind. The simulations include gusts and turbulent winds of varying intensity in nominal as well as off-design operating conditions. The experiments highlight the possible advantages of model-based non-linear control strategies.

  10. Performance comparison of control schemes for variable-speed wind turbines

    International Nuclear Information System (INIS)

    Bottasso, C L; Croce, A; Savini, B

    2007-01-01

    We analyze the performance of different control schemes when applied to the regulation problem of a variable-speed representative wind turbine. In particular, we formulate and compare a wind-scheduled PID, a LQR controller and a novel adaptive non-linear model predictive controller, equipped with observers of the tower states and wind. The simulations include gusts and turbulent winds of varying intensity in nominal as well as off-design operating conditions. The experiments highlight the possible advantages of model-based non-linear control strategies

  11. Permanent Magnet Flux-Switching Machine, Optimal Design and Performance Analysis

    Directory of Open Access Journals (Sweden)

    Liviu Emilian Somesan

    2013-01-01

    Full Text Available In this paper an analytical sizing-design procedure for a typical permanent magnet flux-switching machine (PMFSM with 12 stator and respectively 10 rotor poles is presented. An optimal design, based on Hooke-Jeeves method with the objective functions of maximum torque density, is performed. The results were validated via two dimensions finite element analysis (2D-FEA applied on the optimized structure. The influence of the permanent magnet (PM dimensions and type, respectively of the rotor poles' shape on the machine performance were also studied via 2D-FEA.

  12. Design Tool for Direct Drive Wind Turbine Generators

    DEFF Research Database (Denmark)

    Leban, Krisztina Monika

    . A comparison of the selected machine types in view of up-scaling to 20 [MW] was performed. As an example fitness criterion, the use of active materials for the generators was considered. Based on this, suggestions for 20 [MW] generators were made. The results are discussed and future work, directions......The current work offers a comparison of the proposed machine geometries for 6 [MW] direct drive wind generator candidates with the prospective of up scaling to 20MW. The suggestions are based on a design tool especially built for this investigation. The in-built flexibility of the design tool gives...

  13. Sources of the wind power stations

    International Nuclear Information System (INIS)

    Chudivani, J.; Huettner, L.

    2012-01-01

    The paper deals with problems of the wind power stations. Describes the basic properties of wind energy. Shows and describes the different types of electrical machines used as a source of electricity in the wind power stations. Shows magnetic fields synchronous generator with salient poles and permanent magnets in the program FEMM. Describes methods for assessing of reversing the effects of the wind power stations on the distribution network. (Authors)

  14. Design and fabrication of radial flux permanent magnet generator for wind turbine applications

    International Nuclear Information System (INIS)

    Ashraf, M.M.; Malik, T.N.; Zafar, S.; Raja, U.N.

    2013-01-01

    Presently alternate energy resources are replacing conventional energy sources to produce electrical power to minimize the usage of fossil fuels. Wind power is one of the potential alternate energy resources and is being exploited and deployed actively. The wind energy system is basically composed of two core components: wind turbine and electrical generator. This paper presents the design and fabrication of permanent magnet generator for direct drive wind turbine applications. Radial flux permanent magnet generator (RFPMG) producing three phase alternating current voltage has been designed subject to satisfying the features of low operating shaft speed, higher power density , higher current density, cost effectiveness and compact structure. RFPMG design focuses on usage of neodymium permanent magnets for excitation instead of electromagnets to minimize the excitation arrangement challenges and losses. A 300 W prototype RFPMG has been fabricated. The performance of the generator has been evaluated on specially designed wind tunnel. The generator is directly coupled with wind turbine shaft to eliminate the gearbox losses. No load and load tests show that the performance of the machine is up to the mark. The improved design parameters of power density and current density are 73.2 W/kg and 5.9 A/mm 2 respectively. The same machine output has been rectified using bridge rectifier for battery charging application. The desired output voltages are obtained at minimum shaft speed of the generator. Thus the design of generator confirms its application with small scale domestic wind turbines produci ng direct current supply. (author)

  15. Market Suitability and Performance Tradeoffs Offered by Commercial Wind Turbines across Differing Wind Regimes

    Directory of Open Access Journals (Sweden)

    Souma Chowdhury

    2016-05-01

    Full Text Available The suitability of turbine configurations to different wind resources has been traditionally restricted to considering turbines operating as standalone entities. In this paper, a framework is thus developed to investigate turbine suitability in terms of the minimum cost of energy offered when operating as a group of optimally-micro-sited turbines. The four major steps include: (i characterizing the geographical variation of wind regimes in the onshore U.S. market; (ii determining the best performing turbines for different wind regimes through wind farm layout optimization; (iii developing a metric to quantify the expected market suitability of available turbine configurations; and (iv exploring the best tradeoffs between the cost and capacity factor yielded by these turbines. One hundred thirty one types of commercial turbines offered by major global manufacturers in 2012 are considered for selection. It is found that, in general, higher rated power turbines with medium tower heights are the most favored. Interestingly, further analysis showed that “rotor diameter/hub height” ratios greater than 1.1 are the least attractive for any of the wind classes. It is also observed that although the “cost-capacity factor” tradeoff curve expectedly shifted towards higher capacity factors with increasing wind class, the trend of the tradeoff curve remained practically similar.

  16. Experimental study on natural ventilation performance of one-sided wind catcher

    NARCIS (Netherlands)

    Montazeri, H.; Azizian, R.

    2008-01-01

    Hydrodynamic performance of a one-sided wind catcher was investigated by experimental wind tunnel and smoke visualization testing. Wind catchers or what is called Baud-Geers in Persian language was a main component of buildings in central region of Iran and the neighboring countries. A Baud-Geer is

  17. State of the art on power performance assessments for wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B. [ed.

    1997-12-31

    It is the intention of this meeting to clarify the status of power performance verification and assessment and identify the future needs in terms of applications, research fields and standardization actions, putting emphasis on the following items: Power performance verification for wind farms; Power performance verification for large wind turbines; Power performance verification for wind turbines operating in complex terrain; Assessment of the available international and national standards; Assessment of developed, applied and verified tools for WECS power performance. This Experts Meeting had gathered 14 participants from 6 different countries. 12 presentations were given and although countries with a sizeable wind program, ie. Italy, UK and Spain were not present, it is felt that the meeting gave a fair impression of the contemporary state of the art world wide. Specific problems concerning accurate definition and measurement of wind speed by cup-anemometers were dealt with. Different sources of errors were analysed and valuable new experimental results were presented. Other instruments for wind-speed measurements than cup-anemometers were discussed as well. (EG)

  18. Superconductivity for Large Scale Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth

    2012-10-12

    A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.

  19. Direct and quadrature inductances measurement of the permanent magnetic linear synchronous machines

    International Nuclear Information System (INIS)

    Li Liyi; Hong Junjie; Wu Hongxing; Kou Baoquan; Liu Rizhong

    2011-01-01

    Research highlights: → The d- and q-axis inductances are derived theoretically. → The new measurement principle of the d- and q-axis inductances is analyzed. → A corresponding measuring circuit is developed. → Measurement results match those of the FEM well. -- Abstract: Permanent magnetic linear synchronous machines (PMLSMs) are playing a more important role either in transportation systems or magnetic launch systems, for the excellent advantages. It is indispensable to high performance controllers that some machine parameters are known such as the direct axis (d-axis) and quadrature axis (q-axis) inductances. In this paper, self and mutual inductances of the three-phase winding are deduced by basic electric machinery theory, and the measured inductances are analyzed since the mutual inductances and the corresponding terminals among three-phase windings are changing as different phase winding is concerned. The d- and q-axis inductances are measured with the designed circuit, and the experimental measurement method is validated by the comparison between the experimental and finite element method (FEM) results.

  20. Direct and quadrature inductances measurement of the permanent magnetic linear synchronous machines

    Energy Technology Data Exchange (ETDEWEB)

    Li Liyi [Electrical Engineering Dept./Harbin Institute of Technology, Harbin 150000 (China); Hong Junjie, E-mail: wizard0663@126.co [School of Engineering/Sun Yat-Sen University, Guangzhou 510006 (China); Wu Hongxing; Kou Baoquan; Liu Rizhong [Electrical Engineering Dept./Harbin Institute of Technology, Harbin 150000 (China)

    2011-05-15

    Research highlights: {yields} The d- and q-axis inductances are derived theoretically. {yields} The new measurement principle of the d- and q-axis inductances is analyzed. {yields} A corresponding measuring circuit is developed. {yields} Measurement results match those of the FEM well. -- Abstract: Permanent magnetic linear synchronous machines (PMLSMs) are playing a more important role either in transportation systems or magnetic launch systems, for the excellent advantages. It is indispensable to high performance controllers that some machine parameters are known such as the direct axis (d-axis) and quadrature axis (q-axis) inductances. In this paper, self and mutual inductances of the three-phase winding are deduced by basic electric machinery theory, and the measured inductances are analyzed since the mutual inductances and the corresponding terminals among three-phase windings are changing as different phase winding is concerned. The d- and q-axis inductances are measured with the designed circuit, and the experimental measurement method is validated by the comparison between the experimental and finite element method (FEM) results.

  1. Managing wind turbine reliability and maintenance via performance-based contract

    DEFF Research Database (Denmark)

    Jin, Tongdan; Ding, Yi; Guo, Huairui

    2012-01-01

    between system cost, reliability and spare parts stocking. This analytical insight into the system performance allows the turbine manufacturer to optimize design, production, and after-sales services. The study aims to create a theoretical basis to facilitate the transition of the maintenance paradigm......Performance-based contracting (PBC) is reshaping the acquisition, operation, and maintenance of capital equipment. Under the PBC scheme, we propose a holistic approach for lowering the cost of wind turbine ownership while meeting the availability requirement. Our effects are focused on integrated...... firms who design and market wind turbines, and also provide maintenance and repair service. PBC differs from conventional service contracts in that the wind farmers compensate the service provider for the system performance, not the spare parts and repair labor. We explore the analytical relationship...

  2. Structural design of the Sandia 34-M Vertical Axis Wind Turbine

    Science.gov (United States)

    Berg, D. E.

    Sandia National Laboratories, as the lead DOE laboratory for Vertical Axis Wind Turbine (VAWT) development, is currently designing a 34-meter diameter Darrieus-type VAWT. This turbine will be a research test bed which provides a focus for advancing technology and validating design and fabrication techniques in a size range suitable for utility use. Structural data from this machine will allow structural modeling to be refined and verified for a turbine on which the gravity effects and stochastic wind loading are significant. Performance data from it will allow aerodynamic modeling to be refined and verified. The design effort incorporates Sandia's state-of-the-art analysis tools in the design of a complete machine. The analytic tools used in this design are discussed and the conceptual design procedure is described.

  3. Performance testing of a small vertical-axis wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, R.; Tullis, S.; Ziada, S. [McMaster Univ., Hamilton, ON (Canada). Dept. of Mechanical Engineering

    2007-07-01

    Full-scale wind tunnel testing of a prototype 3.5 kW vertical-axis wind turbine (VAWT) was conducted in a low speed wind tunnel in Ottawa. The tests were conducted to determine nominal power curves as well as the system's structural integrity, safety and operational characteristics. Dimensionless power curves were used to assess the relation between the wind turbine's rotary speed and the produced power for various wind speeds. Tests began at the lowest wind speed and revolutions per minute (RPM) and were gradually increased. A proximity sensor was used to determine the passing frequency of spaced bolts. The aerodynamic performance of the turbine was evaluated using a servo-controlled mechanical variable load with a disc brake calliper and electro-hydraulic servo-actuator. A load cell was used to measure torque produced by the turbine. An active closed loop speed control system was used to regulate the rotary speed of the turbine. The system used a high gain proportional control law to guarantee stability. Calculated power was based on the average rotary speed measurement. Results of the study suggested that the dimensional power performance of the turbine could be predicted from the curve for all rotary speeds and for wind speeds between 8 and 16 m/s. The maximum power coefficient of 0.3 occurred at a tip speed ratio of 1.6. Test results demonstrated that the turbine reached its rated power at 14 m/s. However, the range of tip speed ratios for power production were lower than the range for most other small VAWT. 2 refs., 3 figs.

  4. Numerical Investigations on the Aerodynamic Performance of Wind Turbine:Downwind Versus Upwind Configuration

    Institute of Scientific and Technical Information of China (English)

    Hu Zhou; Decheng Wan

    2015-01-01

    Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory (NREL) phase VI wind turbine in downwind and upwind configurations is presented. The open source toolbox OpenFOAM coupled with arbitrary mesh interface (AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.

  5. Armature reaction effects on a high temperature superconducting field winding of an synchronous machine: experimental results

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech

    2014-01-01

    This paper presents experimental results from the Superwind laboratory setup. Particular focus in the paper has been placed on describing and quantifying the influence of armature reaction on performance of the HTS filed winding. Presented experimental results have confirmed the HTS field winding...

  6. Performance of a 10 kilowatt wind-electric water pumping system for irrigating crops

    Energy Technology Data Exchange (ETDEWEB)

    Vick, B.D.; Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States); Molla, S. [Texas A& M Univ., College Station, TX (United States)

    1997-12-31

    A 10 kW wind-electric water pumping system was tested for field crop irrigation at pumping depths from 50 to 120 m. The wind turbine for this system used a permanent magnet alternator that powered off-the-shelf submersible motors and pumps without the use of an inverter. Pumping performance was determined at the USDA-Agricultural Research Service (ARS), Wind Energy Laboratory in Bushland, TX for the 10 kW wind turbine using a pressure valve and a pressure tank to simulate different pumping depths. Pumping performance was measured for two 10 kW wind turbines of the same type at farms near the cities of Garden City, TX and Stiles, TX. The pumping performance data collected at these actual wells compared favorably with the data collected at the USDA-ARS, Wind Energy Laboratory. If utility generated electricity was accessible, payback on the wind turbine depended on the cost of utility generated electricity and the transmission line extension cost.

  7. Starting-up sequence of the AWEC-60 wind turbine

    International Nuclear Information System (INIS)

    Avia, F.; Cruz, M. de la.

    1991-01-01

    One of the most critical status of the wind turbines operation is the starting-up sequence and the connection to the grid, due to the actuating loads that could be several times the loads during operation at rated conditions. Due to this fact, the control strategy is very important during the starting-up sequence in order to minimize the loads on the machine. For this purpose it is necessary to analyze the behaviour of the wind turbine during that sequence in different wind conditions and machine conditions. This report shows the graphic information about fifty starting-up sequences of the AWEC-60 wind turbine of 60 m. diameter and 1200 kW of rated power, recorded in April 1991 and cut-out wind speed. (author)

  8. Ten years statistics of wind direction and wind velocity measurements performed at the Karlsruhe Nuclear Research Center

    International Nuclear Information System (INIS)

    Becker, M.; Dilger, H.

    1979-06-01

    The measurements of wind direction and wind velocity performed at 60 m and 200 m height were evaluated for one year each and frequency distributions of the measured values were established. The velocity was divided into 1 m/s steps and the direction into 10 0 sectors. The frequency distribution of the wind direction reveals three maxima located in the southwest, northeast and north, respectively. The maximum of the frequency distribution of the wind velocity occurs between 4 and 5 m/s at 200 m height and between 3 and 4 m/s at 60 m height. (orig.) [de

  9. Analysis of Wind Speed Forecasting Error Effects on Automatic Generation Control Performance

    Directory of Open Access Journals (Sweden)

    H. Rajabi Mashhadi

    2014-09-01

    Full Text Available The main goal of this paper is to study statistical indices and evaluate AGC indices in power system which has large penetration of the WTGs. Increasing penetration of wind turbine generations, needs to study more about impacts of it on power system frequency control. Frequency control is changed with unbalancing real-time system generation and load . Also wind turbine generations have more fluctuations and make system more unbalance. Then AGC loop helps to adjust system frequency and the scheduled tie-line powers. The quality of AGC loop is measured by some indices. A good index is a proper measure shows the AGC performance just as the power system operates. One of well-known measures in literature which was introduced by NERC is Control Performance Standards(CPS. Previously it is claimed that a key factor in CPS index is related to standard deviation of generation error, installed power and frequency response. This paper focuses on impact of a several hours-ahead wind speed forecast error on this factor. Furthermore evaluation of conventional control performances in the power systems with large-scale wind turbine penetration is studied. Effects of wind speed standard deviation and also degree of wind farm penetration are analyzed and importance of mentioned factor are criticized. In addition, influence of mean wind speed forecast error on this factor is investigated. The study system is a two area system which there is significant wind farm in one of those. The results show that mean wind speed forecast error has considerable effect on AGC performance while the mentioned key factor is insensitive to this mean error.

  10. Modeling and Finite Element Analysis of Load-Carrying Performance of a Wind Turbine Considering the Influence of Assembly Factors

    Directory of Open Access Journals (Sweden)

    Jianmei Wang

    2017-03-01

    Full Text Available In this work, a wind turbine shrink disk is used as the research object to investigate load-carrying performance of a multi-layer interference fit, and the theoretical model and finite element model are constructed. According to those models, a MW-level turbine shrink disk is designed, and a test device is developed to apply torque to this turbine shrink disk by hydraulic jack. Then, the circumferential slip between the contact surfaces is monitored and the slip of all contact surfaces is zero. This conclusion verifies the reasonability of the proposed models. The effect of the key influencing factors, such as machining deviation, assembly clearance and propel stroke, were analyzed. The contact pressure and load torque of the mating surfaces were obtained by building typical models with different parameters using finite element analysis (FEA. The results show that the minimum assembly clearance and the machining deviation within the machining range have little influence on load-carrying performance of multi-layer interference fit, while having a greater influence on the maximum assembly clearance and the propel stroke. The results also show that the load-carrying performance of a multiple-layer interference fit can be ensured only if the key factors are set within a reasonable design range. To avoid the abnormal operation of equipment caused by insufficient load torque, the propel stroke during practical assembly should be at least 0.95 times the designed propel stroke, which is significant in guiding the design and assembly of the multi-layer interference fit.

  11. Atmospheric stability and topography effects on wind turbine performance and wake properties in complex terrain

    DEFF Research Database (Denmark)

    Han, Xingxing; Liu, Deyou; Xu, Chang

    2018-01-01

    This paper evaluates the influence of atmospheric stability and topography on wind turbine performance and wake properties in complex terrain. To assess atmospheric stability effects on wind turbine performance, an equivalent wind speed calculated with the power output and the manufacture power...... and topography have significant influences on wind turbine performance and wake properties. Considering effects of atmospheric stability and topography will benefit the wind resource assessment in complex terrain....

  12. Performance assessment of a small wind turbine with crossflow runner by numerical simulations

    Energy Technology Data Exchange (ETDEWEB)

    Dragomirescu, A. [University Politehnica of Bucharest, Department of Hydraulics, Hydraulic Machinery and Environmental Engineering, Splaiul Independentei 313, 060042 Bucharest (Romania)

    2011-03-15

    Most of the classical wind turbines are not able to start at wind speeds as low as 2-3 m/s. Other turbines, like Savonius, have a low maximum efficiency, which renders them useless in poor wind conditions. Therefore, new turbine designs are required to harvest wind power even when the wind speed is low. A wind turbine having a crossflow runner, similar to the Banki water turbine, is studied numerically in this work in order to estimate its performance. The results obtained suggest that this turbine has a considerable high starting torque and its maximum power coefficient is comparable to those of horizontal axis wind turbines. Based on the results obtained, some improvements of the design are proposed in order to further increase turbine performance. (author)

  13. AC Losses and Their Thermal Effect in High Temperature Superconducting Machines

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Mijatovic, Nenad; Zou, Shengnan

    2015-01-01

    In transient operations or fault conditions, high temperature superconducting (HTS) machines suffer AC losses which have an influence on the thermal stability of superconducting windings. In this paper, a method to calculate AC losses and their thermal effect in HTS machines is presented....... The method consists of three sub-models that are coupled only in one direction. The magnetic field distribution is first solved in a machine model, assuming a uniform current distribution in HTS windings. The magnetic fields on the boundaries are then used as inputs for an AC loss model which has...

  14. AC Losses and Their Thermal Effect in High-Temperature Superconducting Machines

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Mijatovic, Nenad; Zou, Shengnan

    2016-01-01

    In transient operations or fault conditions, hightemperature superconducting (HTS) machines suffer ac losses, which have an influence on the thermal stability of superconducting windings. In this paper, a method to calculate ac losses and their thermal effect in HTS machines is presented....... The method consists of three submodels that are coupled only in one direction. The magnetic field distribution is first solved in a machine model, assuming a uniform current distribution in HTS windings. The magnetic fields on the boundaries are then used as inputs for an ac loss model that has a homogeneous...

  15. Modern Control Design for Flexible Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A. D.

    2004-07-01

    Control can improve energy capture and reduce dynamic loads in wind turbines. In the 1970s and 1980s, wind turbines used classical control designs to regulate power and speed. The methods used, however, were not always successful. Modern turbines are larger, mounted on taller towers, and more dynamically active than their predecessors. Control systems to regulate turbine power and maintain stable, closed-loop behavior in the presence of turbulent wind inflow will be critical for these designs. This report applies modern state-space control design methods to a two-bladed teetering hub upwind machine at the National Wind Technology Center (NWTC), which is managed by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) in Golden, Colorado. The design objective is to regulate turbine speed and enhance damping in several low-damped flexible modes of the turbine. Starting with simple control algorithms based on linear models, complexity is added incrementally until the desired performance is firmly established.

  16. Wind farms generation limits and its impact in real-time voltage stability assessment

    DEFF Research Database (Denmark)

    Perez, Angel; Jóhannsson, Hjörtur; Østergaard, Jacob

    2015-01-01

    . Thismethodology is tested in a platform that produces synthesizedPMU measurements from time-domain simulations and criticalboundary for the wind-farm limits are shown. The methodology isalso tested for synchronous machines and its parallel structure isexploited when implemented in a High Performance...

  17. Transient thermal analysis of flux switching PM machines

    NARCIS (Netherlands)

    Ilhan, E.; Kremers, M.F.J.; Motoasca, T.E.; Paulides, J.J.H.; Lomonova, E.

    2013-01-01

    Flux switching permanent magnet (FSPM) machines bring together the merits of switched reluctance and PM synchronous motors. FSPM employs armature windings and PMs together in the stator region, therefore the proximity of the windings PMs makes a thermal model mandatory. In literature, thermal

  18. Performance characteristics of a Vertical Axis Wind Turbine (VAWT) under transient conditions

    OpenAIRE

    Colley, Gareth; Mishra, Rakesh

    2011-01-01

    The present work investigates the performance characteristics of a novel Vertical Axis Wind Turbine (VAWT) for use in the urban environment. Here the performance of the wind turbine has been analyzed experimentally using a full scale prototype measuring 2.0m diameter and 1.0m in height. The turbine was located at the exit of a 0.6m x 0.6m wind tunnel section and was subjected to a jet flow. The performance output from the turbine has been obtained using a torque transducer unit which provides...

  19. Performance Analysis of Ivshmem for High-Performance Computing in Virtual Machines

    Science.gov (United States)

    Ivanovic, Pavle; Richter, Harald

    2018-01-01

    High-Performance computing (HPC) is rarely accomplished via virtual machines (VMs). In this paper, we present a remake of ivshmem which can change this. Ivshmem was a shared memory (SHM) between virtual machines on the same server, with SHM-access synchronization included, until about 5 years ago when newer versions of Linux and its virtualization library libvirt evolved. We restored that SHM-access synchronization feature because it is indispensable for HPC and made ivshmem runnable with contemporary versions of Linux, libvirt, KVM, QEMU and especially MPICH, which is an implementation of MPI - the standard HPC communication library. Additionally, MPICH was transparently modified by us to get ivshmem included, resulting in a three to ten times performance improvement compared to TCP/IP. Furthermore, we have transparently replaced MPI_PUT, a single-side MPICH communication mechanism, by an own MPI_PUT wrapper. As a result, our ivshmem even surpasses non-virtualized SHM data transfers for block lengths greater than 512 KBytes, showing the benefits of virtualization. All improvements were possible without using SR-IOV.

  20. An assessment on seasonal analysis of wind energy characteristics and wind turbine characteristics

    International Nuclear Information System (INIS)

    Akpinar, E. Kavak; Akpinar, S.

    2005-01-01

    This paper presents seasonal variations of the wind characteristics and wind turbine characteristics in the regions around Elazig, namely Maden, Agin and Keban. Mean wind speed data in measured hourly time series format is statistically analyzed for the six year period 1998-2003. The probability density distributions are derived from the time series data and their distributional parameters are identified. Two probability density functions are fitted to the measured probability distributions on a seasonal basis. The wind energy characteristics of all the regions is studied based on the Weibull and Rayleigh distributions. Energy calculations and capacity factors for the wind turbine characteristics were determined for wind machines of different sizes between 300 and 2300 kW. It was found that Maden is the best region, among the regions analyzed, for wind characteristics and wind turbine characteristics

  1. Wind power in Denmark technology, policies and results

    Energy Technology Data Exchange (ETDEWEB)

    Dannemand Andersen, Per [ed.] [Risoe National Lab. (Denmark)

    1998-11-01

    The Association of Danish Electricity Utilities has estimated the total electricity production from wind turbines in 1997 as 1932 GWh: 384 GWh from utility-owned turbines and 1548 GWh from privately owned turbines. This equals 6% of total electricity consumption in Denmark. Corrected to a `normal wind year` this equals 6.6% of Denmark`s annual electricity con-sumption. The wind energy index in 1997 was 91%. According to the Danish Association of Electricity Utilities, 4784 turbines with a capacity of 1129 MW were connected to the grid at the end of 1997. 534 turbines and 287 MW were added in 1997, the largest figure ever. These are net figures and included dismantled machines. The actual sales of turbines is a bit higher, reflecting the fact that not all machines sold in 1997 were installed that year. New machines are usually 500 kW, 600 kW and 750 kW. No 1500 kW machines have as yet been installed on a commercial basis in Denmark. (au)

  2. An experimental study on a superconducting generator with dual machine shield system

    International Nuclear Information System (INIS)

    Ishigohka, T.; Ninomiya, A.; Okada, T.; Nitta, T.; Shintani, T.; Mukai, E.

    1988-01-01

    The authors have studied the optimal machine shield system through experiments on a 20kVa superconducting generator. The first experiment is carried out on a fully iron-less aluminum-shield machine which has only an aluminum eddy current machine shield in the stator. The second experiment is carried out on a generator with a dual-shield system which has both an aluminum eddy current shield and an iron magnetic shield. From the first one, the authors have got an experimental result that the aluminum-shield machine exhibits so large eddy current loss in the shield that it would be difficult to operate the machine continuously. On the other hand, the second experiment shows that the dual-shield machine exhibits much smaller loss in the shielding system, and that it has higher output power than the aluminum-shield machine. From these experiments, it becomes clear that insertion of a very thin iron shield between the armature winding and the eddy current shield can improve the machine performance eminently without large weight increase even if the iron shield were saturated

  3. Real And Reactive Power Saving In Three Phase Induction Machine Using Star-Delta Switching Schemes

    Directory of Open Access Journals (Sweden)

    Ramesh Daravath

    2017-04-01

    Full Text Available Induction machines are the most commonly used industrial drives for variety of applications. It has been estimated that induction motors consumes approximately 50 of all the electric energy generated. Further in the area of renewable energy sources such as wind or bio-mass energy induction machines have been found suitable for functioning as generators. In this context it may be mentioned that a star-delta switching is common for the starting of three-phase induction motor. Now it is proposed to use this star-delta switching for energy conservation of induction machines i.e. at times of reduced loads the machine switched back to star connection. Using a three-phase 400 V 50 Hz 4-pole induction machine it has been demonstrated that the star-delta switching of stator winding of three-phase induction machine motor generator operations reconnected in star at suitable reduced loads with a switching arrangement can result in improved efficiency and power factor as compared to a fixed delta or star connection. The predetermined values along with the experimental results have also been presented in this report. A simulation program has been developed for the predetermination of performance of the three-phase induction machine using exact equivalent circuit. A case study on a 250 kW 400 V 4-pole three-phase induction machine operated with different load cycles reveals the significant real and reactive power savings that could be obtained in the present proposal.

  4. Performance Analysis of Millimeter-Wave Multi-hop Machine-to-Machine Networks Based on Hop Distance Statistics

    Directory of Open Access Journals (Sweden)

    Haejoon Jung

    2018-01-01

    Full Text Available As an intrinsic part of the Internet of Things (IoT ecosystem, machine-to-machine (M2M communications are expected to provide ubiquitous connectivity between machines. Millimeter-wave (mmWave communication is another promising technology for the future communication systems to alleviate the pressure of scarce spectrum resources. For this reason, in this paper, we consider multi-hop M2M communications, where a machine-type communication (MTC device with the limited transmit power relays to help other devices using mmWave. To be specific, we focus on hop distance statistics and their impacts on system performances in multi-hop wireless networks (MWNs with directional antenna arrays in mmWave for M2M communications. Different from microwave systems, in mmWave communications, wireless channel suffers from blockage by obstacles that heavily attenuate line-of-sight signals, which may result in limited per-hop progress in MWNs. We consider two routing strategies aiming at different types of applications and derive the probability distributions of their hop distances. Moreover, we provide their baseline statistics assuming the blockage-free scenario to quantify the impact of blockages. Based on the hop distance analysis, we propose a method to estimate the end-to-end performances (e.g., outage probability, hop count, and transmit energy of the mmWave MWNs, which provides important insights into mmWave MWN design without time-consuming and repetitive end-to-end simulation.

  5. Performance Analysis of Millimeter-Wave Multi-hop Machine-to-Machine Networks Based on Hop Distance Statistics.

    Science.gov (United States)

    Jung, Haejoon; Lee, In-Ho

    2018-01-12

    As an intrinsic part of the Internet of Things (IoT) ecosystem, machine-to-machine (M2M) communications are expected to provide ubiquitous connectivity between machines. Millimeter-wave (mmWave) communication is another promising technology for the future communication systems to alleviate the pressure of scarce spectrum resources. For this reason, in this paper, we consider multi-hop M2M communications, where a machine-type communication (MTC) device with the limited transmit power relays to help other devices using mmWave. To be specific, we focus on hop distance statistics and their impacts on system performances in multi-hop wireless networks (MWNs) with directional antenna arrays in mmWave for M2M communications. Different from microwave systems, in mmWave communications, wireless channel suffers from blockage by obstacles that heavily attenuate line-of-sight signals, which may result in limited per-hop progress in MWNs. We consider two routing strategies aiming at different types of applications and derive the probability distributions of their hop distances. Moreover, we provide their baseline statistics assuming the blockage-free scenario to quantify the impact of blockages. Based on the hop distance analysis, we propose a method to estimate the end-to-end performances (e.g., outage probability, hop count, and transmit energy) of the mmWave MWNs, which provides important insights into mmWave MWN design without time-consuming and repetitive end-to-end simulation.

  6. Dynamic modeling of an asynchronous squirrel-cage machine; Modelisation dynamique d'une machine asynchrone a cage

    Energy Technology Data Exchange (ETDEWEB)

    Guerette, D.

    2009-07-01

    This document presented a detailed mathematical explanation and validation of the steps leading to the development of an asynchronous squirrel-cage machine. The MatLab/Simulink software was used to model a wind turbine at variable high speeds. The asynchronous squirrel-cage machine is an electromechanical system coupled to a magnetic circuit. The resulting electromagnetic circuit can be represented as a set of resistances, leakage inductances and mutual inductances. Different models were used for a comparison study, including the Munteanu, Boldea, Wind Turbine Blockset, and SimPowerSystem. MatLab/Simulink modeling results were in good agreement with the results from other comparable models. Simulation results were in good agreement with analytical calculations. 6 refs, 2 tabs, 9 figs.

  7. The calculation of warping spools of warp-knitting machines

    Directory of Open Access Journals (Sweden)

    Vitaliy V. Chaban

    2014-12-01

    Full Text Available The paper is devoted to the development of scientific bases of the knitting machine design, in particular, to the calculation of warping spools of warp-knitting machines. The method of calculating the operating parameters of warping spools and mode of winding is offered. A formula that is obtained allows to define relationship between the parameters of the threads wound on a warping spool, their pull, structural dimensions of spool barrel and the diameter of spooling. With the given spool design and the given value of permissible tension of the material of its barrel, the offered formula allows to determine the maximum tension of the threads in the process of their winding on a spool. By this formula the safe diameter of winding the threads onto the spool can be calculated at a given pull of the threads during winding.

  8. A novel vertical-axis wind turbine for distributed and utility deployment

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.Y. [Inha Univ., Incheon (Korea, Republic of); Lee, S. [Inha Univ., Incheon (Korea, Republic of)]|[KR Wind Energy Research Inst., Incheon (Korea, Republic of); Sabourin, T.; Park, K. [KR Windpower Inc., (United States)

    2008-07-01

    The rapid growth in the wind power industry can be attributed to energy cost saving, power reliability, grid support, and environmental concerns. Wind turbines should also comply with community noise and aesthetic requirements as well as meet a strong need for high capacity. Wind Turbine Generator Systems are classified as either horizontal axis wind turbine (HAWT) or vertical axis wind turbine (VAWT) depending on whether their axis of rotation is parallel or perpendicular to the ground. The average electric power produced by the wind turbine is proportional to the efficiency of the rotor, air density, projected area of the turbine, and cube of wind speed. The capacity factor should be increased to guarantee the economics of the turbine via increase in the rotor size or the turbine efficiency. The low rotational speed of VAWT rotors suggests that the machine will be quieter than the high-rotational speed of HAWTs, thereby being potentially suitable for applications closer to population centres. The slow rotating machine may also be considered to be visually more aesthetic. This paper presented the measured performance of a small-scale VAWT rated as 1 kW which has a tail consisting of a stabilizer and a rudder. It was tested for its electric power produced at specified wind conditions in an open-type wind tunnel. In order to eliminate the inevitable blockage effect by the size of turbine, the flow deceleration effect of the incoming air to the turbine was analyzed through model testing and numerical simulation and implemented to the proto-type testing. The turbine and its furling tail was shown to be safe. 9 refs., 1 tab., 10 figs.

  9. Development of a representative model of a wind turbine in order to study the installation of several machines on a wind park; Developpement d'un modele representatif d'une eolienne afin d'etudier l'implantation de plusieurs machines sur un parc eolien

    Energy Technology Data Exchange (ETDEWEB)

    Jourieh, M

    2007-12-15

    This thesis is devoted to the study of aerodynamics in wind turbines. It is divided into two main parts, one is experimental, and the other deals with modelling and numerical simulation. The velocity field downstream from a three-bladed wind turbine with a horizontal axis is explored in the wind tunnel at ENSAM-Paris. Two measurement techniques are used: hot wire anemometry and Particle Image Velocimetry (PIV). Experimental work gives a clear idea of the structure of the near wake and provides useful data to validate the numerical simulations and the hybrid models which are studied in this thesis. In the work concerning numerical simulation, two hybrid models are defined and implemented: a model of actuator disc and a model of actuator cylinder, coupled with a simulation based on the numerical resolution of the Navier-Stokes equations. These models are validated by the power of the wind turbine and on the velocity field in the near wake of the rotor. The numerical results are compared with the experimental data resulting from the tests carried out by the NREL for NREL phase II and VI cases. The experimental and numerical velocity fields are also compared in the wake of a wind turbine Rutland 503. In both validation cases, power and wake, the experimental data are in accordance with the results provided by the hybrid models. After this validation, the interaction between several wind turbines is studied and quantified. The tested hybrid models are also used to study the interaction between identical wind turbines placed one behind the other. The obtained results highlight the effect of spacing between the machines as well as the effect of free stream velocity. (author)

  10. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  11. Wind turbine optimal control during storms

    International Nuclear Information System (INIS)

    Petrović, V; Bottasso, C L

    2014-01-01

    This paper proposes a control algorithm that enables wind turbine operation in high winds. With this objective, an online optimization procedure is formulated that, based on the wind turbine state, estimates those extremal wind speed variations that would produce maximal allowable wind turbine loads. Optimization results are compared to the actual wind speed and, if there is a danger of excessive loading, the wind turbine power reference is adjusted to ensure that loads stay within allowed limits. This way, the machine can operate safely even above the cut-out wind speed, thereby realizing a soft envelope-protecting cut-out. The proposed control strategy is tested and verified using a high-fidelity aeroservoelastic simulation model

  12. Development and Performance Evaluation of Fluted Pumpkin Seed Dehulling Machine

    Directory of Open Access Journals (Sweden)

    M. M. Odewole

    2017-08-01

    Full Text Available A machine for dehulling fluted pumpkin seed (Telfairia occidentalis was developed. The main objective of developing the machine was to provide a better substitute to traditional methods of dehulling the seed which contains edible oil of high medicinal and nutritional values. Traditional methods are full of drudgery, slow, injury prone and would lead to low and poor outputs in terms of quantity and quality of dehulled products. The machine is made of five major parts: the feed hopper (for holding the seeds to be dehulled before getting into the dehulling chamber, dehulling chamber (the part of the machine that impacts forces on seeds thereby causing fractures and opening of seeds coats for the delivery of the oily kernels, discharge unit (exit for oily kernels and seed coats after dehulling, the frame (for structural support and stability of all parts of the machine and electric motor (power source of the machine.The development process involved design of major components (shaft diameter (20 mm, machine velocity (7.59 m/s, power requirement (3hp single phase electric motor and structural support of mild steel angle iron, selection of construction materials and fabrication. ANSYS R14.5 machine design computer software was used to design the shaft and structural support; while other components were designed with conventional design method of using design equations. The machine works on the principle of centrifugal and impact forces. Performance evaluation was carried out after fabrication and 87.26%, 2.83g/s, 8.9% and 3.84%were obtained for dehulling efficiency, throughput capacity, percentage partially dehulled and percentage undehulled respectively.

  13. Using GPS to evaluate productivity and performance of forest machine systems

    Science.gov (United States)

    Steven E. Taylor; Timothy P. McDonald; Matthew W. Veal; Ton E. Grift

    2001-01-01

    This paper reviews recent research and operational applications of using GPS as a tool to help monitor the locations, travel patterns, performance, and productivity of forest machines. The accuracy of dynamic GPS data collected on forest machines under different levels of forest canopy is reviewed first. Then, the paper focuses on the use of GPS for monitoring forest...

  14. Quality control and performance evaluation of microselectron HDR machine over 30 months

    International Nuclear Information System (INIS)

    Balasubramanian, N.; Annex, E.H.; Sunderam, N.; Patel, N.P.; Kaushal, V.

    2008-01-01

    To assess the performance evaluation of Microselectron HDR machine the standard quality control and quality assurance checks were carried out after each loading of new 192 Ir brachytherapy source In the machine. Total 9 loadings were done over a period of 30 months

  15. Accounting for the speed shear in wind turbine power performance measurement

    DEFF Research Database (Denmark)

    Wagner, Rozenn; Courtney, Michael; Gottschall, Julia

    2011-01-01

    The current IEC standard for wind turbine power performance measurement only requires measurement of the wind speed at hub height assuming this wind speed to be representative for the whole rotor swept area. However, the power output of a wind turbine depends on the kinetic energy flux, which...... itself depends on the wind speed profile, especially for large turbines. Therefore, it is important to characterize the wind profile in front of the turbine, and this should be preferably achieved by measuring the wind speed over the vertical range between lower and higher rotor tips. In this paper, we...... describe an experiment in which wind speed profiles were measured in front of a multimegawatt turbine using a ground–based pulsed lidar. Ignoring the vertical shear was shown to overestimate the kinetic energy flux of these profiles, in particular for those deviating significantly from a power law profile...

  16. The system design and performance test of hybrid vertical axis wind turbine

    Science.gov (United States)

    Dwiyantoro, Bambang Arip; Suphandani, Vivien

    2017-04-01

    Vertical axis wind turbine is a tool that is being developed to generate energy from wind. One cause is still little use of wind energy is the design of wind turbines that are less precise. Therefore in this study will be developed the system design of hybrid vertical axis wind turbine and tested performance with experimental methods. The design of hybrid turbine based on a straight bladed Darrieus turbine along with a double step Savonius turbine. The method used to design wind turbines is by studying literature, analyzing the critical parts of a wind turbine and the structure of the optimal design. Wind turbine prototype of the optimal design characteristic tests in the wind tunnel experimentally by varying the speed of the wind. From the experimental results show that the greater the wind speed, the greater the wind turbine rotation and torque is raised. The hybrid vertical axis wind turbine has much better self-starting and better conversion efficiency.

  17. Performance of Process Damping in Machining Titanium Alloys at Low Cutting Speed with Different Helix Tools

    International Nuclear Information System (INIS)

    Shaharun, M A; Yusoff, A R; Reza, M S; Jalal, K A

    2012-01-01

    Titanium is a strong, lustrous, corrosion-resistant and transition metal with a silver color to produce strong lightweight alloys for industrial process, automotive, medical instruments and other applications. However, it is very difficult to machine the titanium due to its poor machinability. When machining titanium alloys with the conventional tools, the wear rate of the tool is rapidly accelerate and it is generally difficult to achieve at high cutting speed. In order to get better understanding of machining titanium alloy, the interaction between machining structural system and the cutting process which result in machining instability will be studied. Process damping is a useful phenomenon that can be exploited to improve the limited productivity of low speed machining. In this study, experiments are performed to evaluate the performance of process damping of milling under different tool helix geometries. The results showed that the helix of 42° angle is significantly increase process damping performance in machining titanium alloy.

  18. enhancement of the performan machine operating in t nt

    African Journals Online (AJOL)

    eobe

    damper windings, the main and auxiliary wind being located on the ... t power achievable by capacitance injection, the transfer field machine ent induction motor ... e as a function of rotor the saliency in the ... auxiliary supply plant. Figure 1: ...

  19. Aeroelastic analysis of an offshore wind turbine: Design and Fatigue Performance of Large Utility-Scale Wind Turbine Blades

    OpenAIRE

    Fossum, Peter Kalsaas

    2012-01-01

    Aeroelastic design and fatigue analysis of large utility-scale wind turbine blades are performed. The applied fatigue model is based on established methods and is incorporated in an iterative numerical design tool for realistic wind turbine blades. All aerodynamic and structural design properties are available in literature. The software tool FAST is used for advanced aero-servo-elastic load calculations and stress-histories are calculated with elementary beam theory.According to wind energy ...

  20. Evaluation of a micro-scale wind model's performance over realistic building clusters using wind tunnel experiments

    Science.gov (United States)

    Zhang, Ning; Du, Yunsong; Miao, Shiguang; Fang, Xiaoyi

    2016-08-01

    The simulation performance over complex building clusters of a wind simulation model (Wind Information Field Fast Analysis model, WIFFA) in a micro-scale air pollutant dispersion model system (Urban Microscale Air Pollution dispersion Simulation model, UMAPS) is evaluated using various wind tunnel experimental data including the CEDVAL (Compilation of Experimental Data for Validation of Micro-Scale Dispersion Models) wind tunnel experiment data and the NJU-FZ experiment data (Nanjing University-Fang Zhuang neighborhood wind tunnel experiment data). The results show that the wind model can reproduce the vortexes triggered by urban buildings well, and the flow patterns in urban street canyons and building clusters can also be represented. Due to the complex shapes of buildings and their distributions, the simulation deviations/discrepancies from the measurements are usually caused by the simplification of the building shapes and the determination of the key zone sizes. The computational efficiencies of different cases are also discussed in this paper. The model has a high computational efficiency compared to traditional numerical models that solve the Navier-Stokes equations, and can produce very high-resolution (1-5 m) wind fields of a complex neighborhood scale urban building canopy (~ 1 km ×1 km) in less than 3 min when run on a personal computer.

  1. Improved power performance assessment methods

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S; Antoniou, I; Dahlberg, J A [and others

    1999-03-01

    The uncertainty of presently-used methods for retrospective assessment of the productive capacity of wind farms is unacceptably large. The possibilities of improving the accuracy have been investigated and are reported. A method is presented that includes an extended power curve and site calibration. In addition, blockage effects with respect to reference wind speed measurements are analysed. It is found that significant accuracy improvements are possible by the introduction of more input variables such as turbulence and wind shear, in addition to mean wind speed and air density. Also, the testing of several or all machines in the wind farm - instead of only one or two - may provide a better estimate of the average performance. (au)

  2. A 34-meter VAWT (Vertical Axis Wind Turbine) point design

    Science.gov (United States)

    Ashwill, T. D.; Berg, D. E.; Dodd, H. M.; Rumsey, M. A.; Sutherland, H. J.; Veers, P. S.

    The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, including increased energy production, over previous machines. The point design differs minimally from the Test Bed; but by removing research-related items, its estimated cost is substantially reduced. The point design is a first step towards a Test-Bed-based commercial machine that would be competitive with conventional sources of power in the mid-1990s.

  3. Performance of a prototype micro wind turbine in the manmade wind field from air conditioner of buildings

    Directory of Open Access Journals (Sweden)

    K. H. Goh

    2012-03-01

    Full Text Available Harnessing waste energy from the manmade air fields of buildings presents a new area of renewable energy to explore. Due to the unpredictability of the natural wind, this study is to evaluate the practicality for harnessing waste energy from the air conditioner exhaust units which are a more constant and predictable source available in the buildings. A prototype of the micro wind turbine has been designed to minimize the negative effect of the exhaust sources. After the micro wind turbine was manufactured, the performance of the turbine was tested in the selected air conditioner exhaust unit. Increasing the rotor solidity and decreasing the resistance of the generator contribute to improved starting torque and decreased generator break in torque respectively in the design. The power generation of the micro wind turbine increases with an increase of the rotor speed. The 24-hour operation of the prototype presents an observation for both exhaust performance and power generation prediction when the prototype is mounted on the exhaust unit.

  4. Improvement of the dynamic performance of an AC linear permanent magnet machine

    NARCIS (Netherlands)

    Jansen, J.W.; Lomonova, E.; Vandenput, A.J.A.; Compter, J.C.; Verweij, A.H.

    2003-01-01

    This paper discusses the controller design and test approaches leading to the performance improvement of a brushless 3-phase AC synchronous permanent magnet linear machine. The feasible controller design concept for the linear machine is presented and further implemented in Simulink and dSPACE. Two

  5. The Fluid Foil: The Seventh Simple Machine

    Science.gov (United States)

    Mitts, Charles R.

    2012-01-01

    A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

  6. Needs versus bottlenecks in utilization of wind energy in Egypt

    International Nuclear Information System (INIS)

    El Semery, M.M.

    1991-01-01

    The company AOI Engine Factory in Cairo, Egypt, is involved in the production of renewable energy systems. It is shown, that with respect to wind, Egypt has a good potential. However, along the river Nile wind speed is moderate (<4,4 m/s). The three main wind energy developments in Egypt are discussed. Four 100 kW machines for grid connection have been imported from Denmark. These machines have been adapted for local production and operation circumstances. After a testing period the first batch of 100 turbines is now being manufactured. For water pumping in isolated areas, a 15 kW wind generator with two submergible electric pumps have been tested. For small wind generators a considerable market exists, but a design, suitable for local production and adapted to the local wind regime, is not available yet

  7. Solution procedure and performance evaluation for a water–LiBr absorption refrigeration machine

    International Nuclear Information System (INIS)

    Wonchala, Jason; Hazledine, Maxwell; Goni Boulama, Kiari

    2014-01-01

    The water–lithium bromide absorption cooling machine was investigated theoretically in this paper. A detailed solution procedure was proposed and validated. A parametric study was conducted over the entire admissible ranges of the desorber, condenser, absorber and evaporator temperatures. The performance of the machine was evaluated based on the circulation ratio which is a measure of the system size and cost, the first law coefficient of performance and the second law exergy efficiency. The circulation ratio and the coefficient of performance were seen to improve as the temperature of the heat source increased, while the second law performance deteriorated. The same qualitative responses were obtained when the temperature of the refrigerated environment was increased. On the other hand, simultaneously raising the condenser and absorber temperatures was seen to result in a severe deterioration of both the circulation ratio and first law coefficient of performance, while the second law performance indicator improved significantly. The influence of the difference between the condenser and absorber exit temperatures, as well as that of the internal recovery heat exchanger on the different performance indicators was also calculated and discussed. - Highlights: • Analysis of a water–LiBr absorption machine, including detailed solution procedure. • Performance assessed using first and second law considerations, as well as flow ratio. • Effects of heat source and refrigerated environment temperatures on the performance. • Effects of the difference between condenser and absorber temperatures. • Effects of internal heat exchanger efficiency on overall cooling machine performance

  8. Optimization of Tape Winding Process Parameters to Enhance the Performance of Solid Rocket Nozzle Throat Back Up Liners using Taguchi's Robust Design Methodology

    Science.gov (United States)

    Nath, Nayani Kishore

    2017-08-01

    The throat back up liners is used to protect the nozzle structural members from the severe thermal environment in solid rocket nozzles. The throat back up liners is made with E-glass phenolic prepregs by tape winding process. The objective of this work is to demonstrate the optimization of process parameters of tape winding process to achieve better insulative resistance using Taguchi's robust design methodology. In this method four control factors machine speed, roller pressure, tape tension, tape temperature that were investigated for the tape winding process. The presented work was to study the cogency and acceptability of Taguchi's methodology in manufacturing of throat back up liners. The quality characteristic identified was Back wall temperature. Experiments carried out using L 9 ' (34) orthogonal array with three levels of four different control factors. The test results were analyzed using smaller the better criteria for Signal to Noise ratio in order to optimize the process. The experimental results were analyzed conformed and successfully used to achieve the minimum back wall temperature of the throat back up liners. The enhancement in performance of the throat back up liners was observed by carrying out the oxy-acetylene tests. The influence of back wall temperature on the performance of throat back up liners was verified by ground firing test.

  9. Design and experimental validation for direct-drive fault-tolerant permanent-magnet vernier machines.

    Science.gov (United States)

    Liu, Guohai; Yang, Junqin; Chen, Ming; Chen, Qian

    2014-01-01

    A fault-tolerant permanent-magnet vernier (FT-PMV) machine is designed for direct-drive applications, incorporating the merits of high torque density and high reliability. Based on the so-called magnetic gearing effect, PMV machines have the ability of high torque density by introducing the flux-modulation poles (FMPs). This paper investigates the fault-tolerant characteristic of PMV machines and provides a design method, which is able to not only meet the fault-tolerant requirements but also keep the ability of high torque density. The operation principle of the proposed machine has been analyzed. The design process and optimization are presented specifically, such as the combination of slots and poles, the winding distribution, and the dimensions of PMs and teeth. By using the time-stepping finite element method (TS-FEM), the machine performances are evaluated. Finally, the FT-PMV machine is manufactured, and the experimental results are presented to validate the theoretical analysis.

  10. Design and Experimental Validation for Direct-Drive Fault-Tolerant Permanent-Magnet Vernier Machines

    Directory of Open Access Journals (Sweden)

    Guohai Liu

    2014-01-01

    Full Text Available A fault-tolerant permanent-magnet vernier (FT-PMV machine is designed for direct-drive applications, incorporating the merits of high torque density and high reliability. Based on the so-called magnetic gearing effect, PMV machines have the ability of high torque density by introducing the flux-modulation poles (FMPs. This paper investigates the fault-tolerant characteristic of PMV machines and provides a design method, which is able to not only meet the fault-tolerant requirements but also keep the ability of high torque density. The operation principle of the proposed machine has been analyzed. The design process and optimization are presented specifically, such as the combination of slots and poles, the winding distribution, and the dimensions of PMs and teeth. By using the time-stepping finite element method (TS-FEM, the machine performances are evaluated. Finally, the FT-PMV machine is manufactured, and the experimental results are presented to validate the theoretical analysis.

  11. Miniaturisation of Pressure-Sensitive Paint Measurement Systems Using Low-Cost, Miniaturised Machine Vision Cameras.

    Science.gov (United States)

    Quinn, Mark Kenneth; Spinosa, Emanuele; Roberts, David A

    2017-07-25

    Measurements of pressure-sensitive paint (PSP) have been performed using new or non-scientific imaging technology based on machine vision tools. Machine vision camera systems are typically used for automated inspection or process monitoring. Such devices offer the benefits of lower cost and reduced size compared with typically scientific-grade cameras; however, their optical qualities and suitability have yet to be determined. This research intends to show relevant imaging characteristics and also show the applicability of such imaging technology for PSP. Details of camera performance are benchmarked and compared to standard scientific imaging equipment and subsequent PSP tests are conducted using a static calibration chamber. The findings demonstrate that machine vision technology can be used for PSP measurements, opening up the possibility of performing measurements on-board small-scale model such as those used for wind tunnel testing or measurements in confined spaces with limited optical access.

  12. Miniaturisation of Pressure-Sensitive Paint Measurement Systems Using Low-Cost, Miniaturised Machine Vision Cameras

    Directory of Open Access Journals (Sweden)

    Mark Kenneth Quinn

    2017-07-01

    Full Text Available Measurements of pressure-sensitive paint (PSP have been performed using new or non-scientific imaging technology based on machine vision tools. Machine vision camera systems are typically used for automated inspection or process monitoring. Such devices offer the benefits of lower cost and reduced size compared with typically scientific-grade cameras; however, their optical qualities and suitability have yet to be determined. This research intends to show relevant imaging characteristics and also show the applicability of such imaging technology for PSP. Details of camera performance are benchmarked and compared to standard scientific imaging equipment and subsequent PSP tests are conducted using a static calibration chamber. The findings demonstrate that machine vision technology can be used for PSP measurements, opening up the possibility of performing measurements on-board small-scale model such as those used for wind tunnel testing or measurements in confined spaces with limited optical access.

  13. Rotating electric machine with fluid supported parts

    Science.gov (United States)

    Smith, Jr., Joseph L.; Kirtley, Jr., James L.

    1981-01-01

    A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.

  14. Cross-winds effect on the performance of natural draft wet cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Al-Waked, R. [Dhofar Univ., Mechanical Engineering Dept., College of Engineering, Sultanate of Oman (Oman)

    2010-01-15

    Effects of cross-winds on the thermal performance of natural draft wet cooling towers (NDWCTs) have been investigated. A three-dimensional CFD model has been used to determine the effect of cross-winds on NDWCTs performance surrounded by power plant building structures. The three-dimensional CFD model has utilized the standard k-{epsilon} turbulence model as the turbulence closure. Two cases have been investigated: a stand-alone NDWCT and two NDWCTs within a proposed power plant structures (PPS). It has been found that regardless of the cross-winds direction, an increase of 1.3 k or more could be predicted at cross-winds speeds greater than 4 m/s. Furthermore, the performance of NDWCTs under cross-winds has been found to be dependent on the three major factors: the structure of the approaching cross-winds and whether it is disturbed or undisturbed, the location of the NDWCT in the wake of the other NDWCT, and the location of the NDWCT in front of/in the wake of the PPS. When comparing results from the stand-alone and from the NDWCTs within PPS simulations, differences in {delta}T{sub wo} were found to be less than 1 K for the whole span of cross-winds speeds and could be decreased to 0.7 K for speeds less than 8 m/s. Finally, results obtained from the simulation of a stand-alone NDWCT could be used instead of those from NDWCTs within PPS at a certain cross-winds direction for qualitative comparisons. (authors)

  15. Cross-winds effect on the performance of natural draft wet cooling towers

    International Nuclear Information System (INIS)

    Al-Waked, R.

    2010-01-01

    Effects of cross-winds on the thermal performance of natural draft wet cooling towers (NDWCTs) have been investigated. A three-dimensional CFD model has been used to determine the effect of cross-winds on NDWCTs performance surrounded by power plant building structures. The three-dimensional CFD model has utilized the standard k-ε turbulence model as the turbulence closure. Two cases have been investigated: a stand-alone NDWCT and two NDWCTs within a proposed power plant structures (PPS). It has been found that regardless of the cross-winds direction, an increase of 1.3 k or more could be predicted at cross-winds speeds greater than 4 m/s. Furthermore, the performance of NDWCTs under cross-winds has been found to be dependent on the three major factors: the structure of the approaching cross-winds and whether it is disturbed or undisturbed, the location of the NDWCT in the wake of the other NDWCT, and the location of the NDWCT in front of/in the wake of the PPS. When comparing results from the stand-alone and from the NDWCTs within PPS simulations, differences in ΔT wo were found to be less than 1 K for the whole span of cross-winds speeds and could be decreased to 0.7 K for speeds less than 8 m/s. Finally, results obtained from the simulation of a stand-alone NDWCT could be used instead of those from NDWCTs within PPS at a certain cross-winds direction for qualitative comparisons. (authors)

  16. Experimental study of wind tunnel performance by a two-component laserDopplerAnemometer

    Directory of Open Access Journals (Sweden)

    M Pourmahabadian

    2005-10-01

    Full Text Available Background and Aims: This survey studies the wind tunnel performance by a two- componentlaser Doppler Anemometer, so some experiments were carried out to assess the performance of awind tunnel.Method: The tunnel was capable to produce air velocity of up to 40 m/s.. Measurements ofvelocity profiles have been made actors the test section of wind tunnel through the using a twocomponentfiber optic Laser Doppler anemometer. Measurements of velocity profiles andturbulence intensities have been made across the test section of the wind tunnel using a twocomponentfiber optic Laser Doppler anemometer (I.D.A for wind speeds ranging from 1 to3m/s.Results: Performance rests of velocity profiles at a given flow rate and various position of aerosolgenerator showed that although uniformity of flow dependent to the place of an atomizer (asaerosol generator but the variation of wind speed across the test section meets the wind speedrequirements, as specified by US EPAfor 3m/s only.Conclusion:At time which particles velocity reach to less than one micron, the air velocity relateson the similarity of particles and

  17. On the Turbulent Mixing in Horizontal Axis Wind Turbine Wakes

    NARCIS (Netherlands)

    Lignarolo, L.E.M.

    2016-01-01

    The wake flow of a horizontal axis wind turbine is characterised by lower wind speed and higher turbulence than the free-stream conditions. When clustered in large wind farms, wind turbines regularly operate inside the wake of one or more upstream machines. This is a major cause of energy production

  18. Wind Power: A Turning Point. Worldwatch Paper 45.

    Science.gov (United States)

    Flavin, Christopher

    Recent studies have shown wind power to be an eminently practical and potentially substantial source of electricity and direct mechanical power. Wind machines range from simple water-pumping devices made of wood and cloth to large electricity producing turbines with fiberglass blades nearly 300 feet long. Wind is in effect a form of solar…

  19. Development and Validation of a Rating Scale for Wind Jazz Improvisation Performance

    Science.gov (United States)

    Smith, Derek T.

    2009-01-01

    The purpose of this study was to construct and validate a rating scale for collegiate wind jazz improvisation performance. The 14-item Wind Jazz Improvisation Evaluation Scale (WJIES) was constructed and refined through a facet-rational approach to scale development. Five wind jazz students and one professional jazz educator were asked to record…

  20. Shoosing the appropriate size wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Lynette, R. [FloWind Corp., San Rafael, CA (United States)

    1996-12-31

    Within the past several years, wind turbines rated at 400 kW and higher have been introduced into the market, and some manufacturers are developing machines rated at 750 - 1,000+ kW. This raises the question: What is the appropriate size for utility-grade wind turbines today? The answer depends upon the site where the machines will be used and the local conditions. The issues discussed in the paper are: (1) Site-Related (a) Visual, noise, erosion, television interference, interference with aviation (b) Siting efficiency (2) Logistics (a) Adequacy of roads and bridges to accept large vehicles (b) Availability and cost of cranes for erection and maintenance (c) Capability of local repair/overhauls (3) Cost Effectiveness (a) Capital costs (1) Wind Turbine (2) Infrastructure costs (b) Maintenance costs (4) Technical/Financial Risk. 1 fig., 1 tab.

  1. Quiet airfoils for small and large wind turbines

    Science.gov (United States)

    Tangler, James L [Boulder, CO; Somers, Dan L [Port Matilda, PA

    2012-06-12

    Thick airfoil families with desirable aerodynamic performance with minimal airfoil induced noise. The airfoil families are suitable for a variety of wind turbine designs and are particularly well-suited for use with horizontal axis wind turbines (HAWTs) with constant or variable speed using pitch and/or stall control. In exemplary embodiments, a first family of three thick airfoils is provided for use with small wind turbines and second family of three thick airfoils is provided for use with very large machines, e.g., an airfoil defined for each of three blade radial stations or blade portions defined along the length of a blade. Each of the families is designed to provide a high maximum lift coefficient or high lift, to exhibit docile stalls, to be relatively insensitive to roughness, and to achieve a low profile drag.

  2. Design study of 10 kW superconducting generator for wind turbine applications

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen

    2009-01-01

    = 1 Tesla to be similar to the performance of permanent magnets and to represent a layout, which can be scaled up in future off-shore wind turbines. The proposed generator is a 8 pole synchronous machine based on race-track coils of high temperature superconducting tapes and an air cored copper stator...

  3. TRACEABILITY OF ON COORDINATE MEASURING MACHINES – CALIBRATION AND PERFORMANCE VERIFICATION

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Savio, Enrico; Bariani, Paolo

    This document is used in connection with three exercises each of 45 minutes duration as a part of the course GEOMETRICAL METROLOGY AND MACHINE TESTING. The exercises concern three aspects of coordinate measurement traceability: 1) Performance verification of a CMM using a ball bar; 2) Calibration...... of an optical coordinate measuring machine; 3) Uncertainty assessment using the ISO 15530-3 “Calibrated workpieces” procedure....

  4. Method and apparatus for characterizing and enhancing the functional performance of machine tools

    Science.gov (United States)

    Barkman, William E; Babelay, Jr., Edwin F; Smith, Kevin Scott; Assaid, Thomas S; McFarland, Justin T; Tursky, David A; Woody, Bethany; Adams, David

    2013-04-30

    Disclosed are various systems and methods for assessing and improving the capability of a machine tool. The disclosure applies to machine tools having at least one slide configured to move along a motion axis. Various patterns of dynamic excitation commands are employed to drive the one or more slides, typically involving repetitive short distance displacements. A quantification of a measurable merit of machine tool response to the one or more patterns of dynamic excitation commands is typically derived for the machine tool. Examples of measurable merits of machine tool performance include workpiece surface finish, and the ability to generate chips of the desired length.

  5. Predicting the Performance of Chain Saw Machines Based on Shore Scleroscope Hardness

    Science.gov (United States)

    Tumac, Deniz

    2014-03-01

    Shore hardness has been used to estimate several physical and mechanical properties of rocks over the last few decades. However, the number of researches correlating Shore hardness with rock cutting performance is quite limited. Also, rather limited researches have been carried out on predicting the performance of chain saw machines. This study differs from the previous investigations in the way that Shore hardness values (SH1, SH2, and deformation coefficient) are used to determine the field performance of chain saw machines. The measured Shore hardness values are correlated with the physical and mechanical properties of natural stone samples, cutting parameters (normal force, cutting force, and specific energy) obtained from linear cutting tests in unrelieved cutting mode, and areal net cutting rate of chain saw machines. Two empirical models developed previously are improved for the prediction of the areal net cutting rate of chain saw machines. The first model is based on a revised chain saw penetration index, which uses SH1, machine weight, and useful arm cutting depth as predictors. The second model is based on the power consumed for only cutting the stone, arm thickness, and specific energy as a function of the deformation coefficient. While cutting force has a strong relationship with Shore hardness values, the normal force has a weak or moderate correlation. Uniaxial compressive strength, Cerchar abrasivity index, and density can also be predicted by Shore hardness values.

  6. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  7. All wind farm uncertainty is not the same: The economics of common versus independent causes

    International Nuclear Information System (INIS)

    Veers, P.S.

    1994-01-01

    There is uncertainty in the performance of wind energy installations due to unknowns in the local wind environment, machine response to the environment, and the durability of materials. Some of the unknowns are inherently independent from machine to machine while other uncertainties are common to the entire fleet equally. The FAROW computer software for fatigue and reliability of wind turbines is used to calculate the probability of component failure due to a combination of all sources of uncertainty. Although the total probability of component failure due to all effects is sometimes interpreted as the percentage of components likely to fail, this perception is often far from correct. Different amounts of common versus independent uncertainty are reflected in economic risk due to either high probabilities that a small percentage of the fleet will experience problems or low probabilities that the entire fleet will have problems. The average, or expected cost is the same as would be calculated by combining all sources of uncertainty, but the risk to the fleet may be quite different in nature. Present values of replacement costs are compared for two examples reflecting different stages in the design and development process. Results emphasize that an engineering effort to test and evaluate the design assumptions is necessary to advance a design from the high uncertainty of the conceptual stages to the lower uncertainty of a well engineered and tested machine

  8. Comparison of alternative offshore wind farms and HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, M. [Technische Univ. Dresden (Germany); Lilje, P.; Poeller, M. [DIgSILENT GmbH, Gomaringen (Germany); Basteck, A. [Voith Turbo Wind GmbH und Co. KG, Crailsheim (Germany)

    2010-07-01

    This paper investigates the stability of offshore wind farms connected to the main power system via HVDC systems. Wind farms consisting of different ratios of directly connected synchronous machines and doubly-fed induction machines are considered. In addition, both conventional LCC- and VSC-type HVDC systems are considered. Furthermore, different control strategies are considered. Furthermore, different control strategies are considered for the VSC-based system, including constant frequency control and frequency regulation. The stability analysis is done by means of time-domain simulation. The maximum and minimum ratio of the two wind turbine technologies is found for each of the different HVDC systems. (orig.)

  9. Short-Term Wind Speed Prediction Using EEMD-LSSVM Model

    Directory of Open Access Journals (Sweden)

    Aiqing Kang

    2017-01-01

    Full Text Available Hybrid Ensemble Empirical Mode Decomposition (EEMD and Least Square Support Vector Machine (LSSVM is proposed to improve short-term wind speed forecasting precision. The EEMD is firstly utilized to decompose the original wind speed time series into a set of subseries. Then the LSSVM models are established to forecast these subseries. Partial autocorrelation function is adopted to analyze the inner relationships between the historical wind speed series in order to determine input variables of LSSVM models for prediction of every subseries. Finally, the superposition principle is employed to sum the predicted values of every subseries as the final wind speed prediction. The performance of hybrid model is evaluated based on six metrics. Compared with LSSVM, Back Propagation Neural Networks (BP, Auto-Regressive Integrated Moving Average (ARIMA, combination of Empirical Mode Decomposition (EMD with LSSVM, and hybrid EEMD with ARIMA models, the wind speed forecasting results show that the proposed hybrid model outperforms these models in terms of six metrics. Furthermore, the scatter diagrams of predicted versus actual wind speed and histograms of prediction errors are presented to verify the superiority of the hybrid model in short-term wind speed prediction.

  10. Wind energy R and D at PG and E

    International Nuclear Information System (INIS)

    Steeley, W.J.

    1992-01-01

    PG and E's Department of Research and Development (R and D) is involved in several wind energy projects. The performance of the wind turbines in Altamont Pass, Solano County, and Pacheco Pass has been monitored since 1981. As of December 1991, there is a total of about 825 MW of wind power in PG and E's service territory. The wind turbines in these areas produced about 1,160,000,000 kWh in 1990, which corresponds to an overall capacity factor of 16%. This is about 1.5% of PG and E's system load. PG and E is planning to begin an advanced wind power plant demonstration in 1992. This paper reports that the project objectives are to evaluate the technical and economic characteristics of advanced wind energy plant designs; to establish construction, operation, and maintenance requirements and practices; and to evaluate emerging machines that show potential for significant advances over present technology. U.S. Windpower, the Electric Power Research Institute, Niagara Mohawk Power, and PG and E are involved in a joint program to develop a variable speed advanced wind turbine. PG and E is providing development funding and reviewing the design from an operation and maintenance perspective

  11. Performance of spanish wind turbines; Estadisticas de produccion de parques eolicos en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Lago, C

    1995-07-01

    In this document we can find a statistical evaluation for the wind energy generation from each spanish wind farm referred to 1994, going on with the work that has been carried out since 1992, by initiative of the Wind Energy Division from Renewable Energy Institute. The purpose of this work is to contribute with interesting information for the wind environment and offer a global view from monthly performances of different wind farms. (Author)

  12. Design and Performance Improvement of AC Machines Sharing a Common Stator

    Science.gov (United States)

    Guo, Lusu

    With the increasing demand on electric motors in various industrial applications, especially electric powered vehicles (electric cars, more electric aircrafts and future electric ships and submarines), both synchronous reluctance machines (SynRMs) and interior permanent magnet (IPM) machines are recognized as good candidates for high performance variable speed applications. Developing a single stator design which can be used for both SynRM and IPM motors is a good way to reduce manufacturing and maintenance cost. SynRM can be used as a low cost solution for many electric driving applications and IPM machines can be used in power density crucial circumstances or work as generators to meet the increasing demand for electrical power on board. In this research, SynRM and IPM machines are designed sharing a common stator structure. The prototype motors are designed with the aid of finite element analysis (FEA). Machine performances with different stator slot and rotor pole numbers are compared by FEA. An 18-slot, 4-pole structure is selected based on the comparison for this prototype design. Sometimes, torque pulsation is the major drawback of permanent magnet synchronous machines. There are several sources of torque pulsations, such as back-EMF distortion, inductance variation and cogging torque due to presence of permanent magnets. To reduce torque pulsations in permanent magnet machines, all the efforts can be classified into two categories: one is from the design stage, the structure of permanent magnet machines can be optimized with the aid of finite element analysis. The other category of reducing torque pulsation is after the permanent magnet machine has been manufactured or the machine structure cannot be changed because of other reasons. The currents fed into the permanent magnet machine can be controlled to follow a certain profile which will make the machine generate a smoother torque waveform. Torque pulsation reduction methods in both categories will be

  13. Performance Characterization and Auto-Ignition Performance of a Rapid Compression Machine

    OpenAIRE

    Hao Liu; Hongguang Zhang; Zhicheng Shi; Haitao Lu; Guangyao Zhao; Baofeng Yao

    2014-01-01

    A rapid compression machine (RCM) test bench is developed in this study. The performance characterization and auto-ignition performance tests are conducted at an initial temperature of 293 K, a compression ratio of 9.5 to 16.5, a compressed temperature of 650 K to 850 K, a driving gas pressure range of 0.25 MPa to 0.7 MPa, an initial pressure of 0.04 MPa to 0.09 MPa, and a nitrogen dilution ratio of 35% to 65%. A new type of hydraulic piston is used to address the problem in which the hydraul...

  14. Integrated analysis of wind turbines - The impact of power systems on wind turbine design

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio

    Megawatt-size wind turbines nowadays operate in very complex environmental conditions, and increasingly demanding power system requirements. Pursuing a cost-effective and reliable wind turbine design is a multidisciplinary task. However nowadays, wind turbine design and research areas...... conditions that stem from disturbances in the power system. An integrated simulation environment, wind turbine models, and power system models are developed in order to take an integral perspective that considers the most important aeroelastic, structural, electrical, and control dynamics. Applications...... of the integrated simulation environment are presented. The analysis of an asynchronous machine, and numerical simulations of a fixedspeed wind turbine in the integrated simulation environment, demonstrate the effects on structural loads of including the generator rotor fluxes dynamics in aeroelastic studies. Power...

  15. Novel Transverse Flux Machine for Vehicle Traction Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Z.; Ahmed, A.; Husain, I.; Muljadi, E.

    2015-04-02

    A novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.

  16. Multi-Response Parameter Interval Sensitivity and Optimization for the Composite Tape Winding Process

    Science.gov (United States)

    Yu, Tao; Kang, Chao; Zhao, Pan

    2018-01-01

    The composite tape winding process, which utilizes a tape winding machine and prepreg tapes, provides a promising way to improve the quality of composite products. Nevertheless, the process parameters of composite tape winding have crucial effects on the tensile strength and void content, which are closely related to the performances of the winding products. In this article, two different object values of winding products, including mechanical performance (tensile strength) and a physical property (void content), were respectively calculated. Thereafter, the paper presents an integrated methodology by combining multi-parameter relative sensitivity analysis and single-parameter sensitivity analysis to obtain the optimal intervals of the composite tape winding process. First, the global multi-parameter sensitivity analysis method was applied to investigate the sensitivity of each parameter in the tape winding processing. Then, the local single-parameter sensitivity analysis method was employed to calculate the sensitivity of a single parameter within the corresponding range. Finally, the stability and instability ranges of each parameter were distinguished. Meanwhile, the authors optimized the process parameter ranges and provided comprehensive optimized intervals of the winding parameters. The verification test validated that the optimized intervals of the process parameters were reliable and stable for winding products manufacturing. PMID:29385048

  17. A Free Wake Numerical Simulation for Darrieus Vertical Axis Wind Turbine Performance Prediction

    Science.gov (United States)

    Belu, Radian

    2010-11-01

    In the last four decades, several aerodynamic prediction models have been formulated for the Darrieus wind turbine performances and characteristics. We can identified two families: stream-tube and vortex. The paper presents a simplified numerical techniques for simulating vertical axis wind turbine flow, based on the lifting line theory and a free vortex wake model, including dynamic stall effects for predicting the performances of a 3-D vertical axis wind turbine. A vortex model is used in which the wake is composed of trailing stream-wise and shedding span-wise vortices, whose strengths are equal to the change in the bound vortex strength as required by the Helmholz and Kelvin theorems. Performance parameters are computed by application of the Biot-Savart law along with the Kutta-Jukowski theorem and a semi-empirical stall model. We tested the developed model with an adaptation of the earlier multiple stream-tube performance prediction model for the Darrieus turbines. Predictions by using our method are shown to compare favorably with existing experimental data and the outputs of other numerical models. The method can predict accurately the local and global performances of a vertical axis wind turbine, and can be used in the design and optimization of wind turbines for built environment applications.

  18. Binary pressure-sensitive paint measurements using miniaturised, colour, machine vision cameras

    Science.gov (United States)

    Quinn, Mark Kenneth

    2018-05-01

    Recent advances in machine vision technology and capability have led to machine vision cameras becoming applicable for scientific imaging. This study aims to demonstrate the applicability of machine vision colour cameras for the measurement of dual-component pressure-sensitive paint (PSP). The presence of a second luminophore component in the PSP mixture significantly reduces its inherent temperature sensitivity, increasing its applicability at low speeds. All of the devices tested are smaller than the cooled CCD cameras traditionally used and most are of significantly lower cost, thereby increasing the accessibility of such technology and techniques. Comparisons between three machine vision cameras, a three CCD camera, and a commercially available specialist PSP camera are made on a range of parameters, and a detailed PSP calibration is conducted in a static calibration chamber. The findings demonstrate that colour machine vision cameras can be used for quantitative, dual-component, pressure measurements. These results give rise to the possibility of performing on-board dual-component PSP measurements in wind tunnels or on real flight/road vehicles.

  19. High-performance permanent magnet brushless motors with balanced concentrated windings and similar slot and pole numbers

    International Nuclear Information System (INIS)

    Stumberger, Bojan; Stumberger, Gorazd; Hadziselimovic, Miralem; Hamler, Anton; Trlep, Mladen; Gorican, Viktor; Jesenik, Marko

    2006-01-01

    The paper presents a comparison between the performances of exterior-rotor permanent magnet brushless motors with distributed windings and the performances of exterior-rotor permanent magnet brushless motors with concentrated windings. Finite element method analysis is employed to determine the performance of each motor. It is shown that motors with concentrated windings and similar slot and pole numbers exhibit similar or better performances than motors with distributed windings for brushless AC (BLAC) operation mode and brushless DC (BLDC) operation mode as well

  20. Starting-up sequence of the AWEC-6 0 wind turbine

    International Nuclear Information System (INIS)

    Avia, F.; Cruz, M. de la

    1991-01-01

    One of the most critical status of the wind turbines operation is the starting-up sequence and the connection to the grid, due to the actuating loads that could be several times the loads during operation at rated conditions. Due to this fact, the control strategy is very important during the starting-up sequence in order to minimize the loads on the machine. For this purpose it is necessary to analyze the behaviour of the wind turbine during that sequence in different wind conditions and machine conditions This report shows the graphic Information about fifty starting-up sequences of the AWEC-60 wind turbine of 60 m diameter and 1200 kW of rated power, recorded in April 1991 and covering all the operation range between cut-in and cut-out wind speed. (Author) 2 refs

  1. An offshore wind farm with dc grid connection and its performance under power system transients

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2011-01-01

    by disconnections. This paper presents a transient performance study of an offshore wind farm with HVDC transmission for grid connection, where the wind turbines in the offshore wind farm are also connected with dc collection network. A power-reduction control strategy (PRCS) for transient performance improvement...

  2. Wind Farm Layout Optimization through a Crossover-Elitist Evolutionary Algorithm performed over a High Performing Analytical Wake Model

    Science.gov (United States)

    Kirchner-Bossi, Nicolas; Porté-Agel, Fernando

    2017-04-01

    Wind turbine wakes can significantly disrupt the performance of further downstream turbines in a wind farm, thus seriously limiting the overall wind farm power output. Such effect makes the layout design of a wind farm to play a crucial role on the whole performance of the project. An accurate definition of the wake interactions added to a computationally compromised layout optimization strategy can result in an efficient resource when addressing the problem. This work presents a novel soft-computing approach to optimize the wind farm layout by minimizing the overall wake effects that the installed turbines exert on one another. An evolutionary algorithm with an elitist sub-optimization crossover routine and an unconstrained (continuous) turbine positioning set up is developed and tested over an 80-turbine offshore wind farm over the North Sea off Denmark (Horns Rev I). Within every generation of the evolution, the wind power output (cost function) is computed through a recently developed and validated analytical wake model with a Gaussian profile velocity deficit [1], which has shown to outperform the traditionally employed wake models through different LES simulations and wind tunnel experiments. Two schemes with slightly different perimeter constraint conditions (full or partial) are tested. Results show, compared to the baseline, gridded layout, a wind power output increase between 5.5% and 7.7%. In addition, it is observed that the electric cable length at the facilities is reduced by up to 21%. [1] Bastankhah, Majid, and Fernando Porté-Agel. "A new analytical model for wind-turbine wakes." Renewable Energy 70 (2014): 116-123.

  3. A variable-mode stator consequent pole memory machine

    Science.gov (United States)

    Yang, Hui; Lyu, Shukang; Lin, Heyun; Zhu, Z. Q.

    2018-05-01

    In this paper, a variable-mode concept is proposed for the speed range extension of a stator-consequent-pole memory machine (SCPMM). An integrated permanent magnet (PM) and electrically excited control scheme is utilized to simplify the flux-weakening control instead of relatively complicated continuous PM magnetization control. Due to the nature of memory machine, the magnetization state of low coercive force (LCF) magnets can be easily changed by applying either a positive or negative current pulse. Therefore, the number of PM poles may be changed to satisfy the specific performance requirement under different speed ranges, i.e. the machine with all PM poles can offer high torque output while that with half PM poles provides wide constant power range. In addition, the SCPMM with non-magnetized PMs can be considered as a dual-three phase electrically excited reluctance machine, which can be fed by an open-winding based dual inverters that provide direct current (DC) bias excitation to further extend the speed range. The effectiveness of the proposed variable-mode operation for extending its operating region and improving the system reliability is verified by both finite element analysis (FEA) and experiments.

  4. Evaluating the impact of electrical grid connection on the wind turbine performance for Hofa wind farm scheme in Jordan

    International Nuclear Information System (INIS)

    Abderrazzaq, M.H.; Aloquili, O.

    2008-01-01

    The growth of wind energy is attributed to the development of turbine size and the increase in number of units in each wind farm. The current modern design of large wind turbines (WT) is directed towards producing efficient, sensitive and reliable units. To achieve this goal, modern turbines are equipped with several devices which are operated with highly advanced electronic circuits. Sensing instruments, measuring devices and control processes of major systems and subsystems are based on various types of electronic apparatus and boards. These boards are very sensitive to the voltage variations caused by abnormal conditions in both the turbine itself and the electric grid to which the wind farm is connected. This paper evaluates wind farm records and proposes a number of methods to overcome such obstacles associated with the design of large wind turbines. Several cases of grid abnormality such as sudden feeder interruption due to the short circuit, network disconnection, voltage variation and circuit breaker opening affecting wind turbines operation and availability are classified and presented. The weight of such impact is determined for each type of disturbances associated with electronic problems in the wind turbine. Wind turbine performance at Hofa wind farm scheme in Jordan is taken as a case study

  5. Classification of solar wind with machine learning

    NARCIS (Netherlands)

    E. Camporeale (Enrico); A. Carè (Algo); J.E. Borovsky (Joseph)

    2017-01-01

    htmlabstractWe present a four-category classification algorithm for the solar wind, based on Gaussian Process. The four categories are the ones previously adopted in Xu and Borovsky (2015): ejecta, coronal hole origin plasma, streamer belt origin plasma, and sector reversal origin plasma. The

  6. Performance Investigation of A Mix Wind Turbine Using A Clutch Mechanism At Low Wind Speed Condition

    Science.gov (United States)

    Jamanun, M. J.; Misaran, M. S.; Rahman, M.; Muzammil, W. K.

    2017-07-01

    Wind energy is one of the methods that generates energy from sustainable resources. This technology has gained prominence in this era because it produces no harmful product to the society. There is two fundamental type of wind turbine are generally used this day which is Horizontal axis wind turbine (HAWT) and Vertical axis wind turbine (VAWT). The VAWT technology is more preferable compare to HAWT because it gives better efficiency and cost effectiveness as a whole. However, VAWT is known to have distinct disadvantage compared to HAWT; self-start ability and efficiency at low wind speed condition. Different solution has been proposed to solve these issues which includes custom design blades, variable angle of attack mechanism and mix wind turbine. A new type of clutch device was successfully developed in UMS to be used in a mix Savonius-Darrieus wind turbine configuration. The clutch system which barely audible when in operation compared to a ratchet clutch system interconnects the Savonius and Darrieus rotor; allowing the turbine to self-start at low wind speed condition as opposed to a standalone Darrieus turbine. The Savonius height were varied at three different size in order to understand the effect of the Savonius rotor to the mix wind turbine performance. The experimental result shows that the fabricated Savonius rotor show that the height of the Savonius rotor affecting the RPM for the turbine. The swept area (SA), aspect ratio (AR) and tip speed ratio (TSR) also calculated in this paper. The highest RPM recorded in this study is 90 RPM for Savonius rotor 0.22-meter height at 2.75 m/s. The Savonius rotor 0.22-meter also give the highest TSR for each range of speed from 0.75 m/s, 1.75 m/s and 2.75 m/s where it gives 1.03 TSR, 0.76 TSR, and 0.55 TSR.

  7. Performance of automatic generation control mechanisms with large-scale wind power

    Energy Technology Data Exchange (ETDEWEB)

    Ummels, B.C.; Gibescu, M.; Paap, G.C. [Delft Univ. of Technology (Netherlands); Kling, W.L. [Transmission Operations Department of TenneT bv (Netherlands)

    2007-11-15

    The unpredictability and variability of wind power increasingly challenges real-time balancing of supply and demand in electric power systems. In liberalised markets, balancing is a responsibility jointly held by the TSO (real-time power balancing) and PRPs (energy programs). In this paper, a procedure is developed for the simulation of power system balancing and the assessment of AGC performance in the presence of large-scale wind power, using the Dutch control zone as a case study. The simulation results show that the performance of existing AGC-mechanisms is adequate for keeping ACE within acceptable bounds. At higher wind power penetrations, however, the capabilities of the generation mix are increasingly challenged and additional reserves are required at the same level. (au)

  8. Analyzing complex wake-terrain interactions and its implications on wind-farm performance.

    Science.gov (United States)

    Tabib, Mandar; Rasheed, Adil; Fuchs, Franz

    2016-09-01

    Rotating wind turbine blades generate complex wakes involving vortices (helical tip-vortex, root-vortex etc.).These wakes are regions of high velocity deficits and high turbulence intensities and they tend to degrade the performance of down-stream turbines. Hence, a conservative inter-turbine distance of up-to 10 times turbine diameter (10D) is sometimes used in wind-farm layout (particularly in cases of flat terrain). This ensures that wake-effects will not reduce the overall wind-farm performance, but this leads to larger land footprint for establishing a wind-farm. In-case of complex-terrain, within a short distance (say 10D) itself, the nearby terrain can rise in altitude and be high enough to influence the wake dynamics. This wake-terrain interaction can happen either (a) indirectly, through an interaction of wake (both near tip vortex and far wake large-scale vortex) with terrain induced turbulence (especially, smaller eddies generated by small ridges within the terrain) or (b) directly, by obstructing the wake-region partially or fully in its flow-path. Hence, enhanced understanding of wake- development due to wake-terrain interaction will help in wind farm design. To this end the current study involves: (1) understanding the numerics for successful simulation of vortices, (2) understanding fundamental vortex-terrain interaction mechanism through studies devoted to interaction of a single vortex with different terrains, (3) relating influence of vortex-terrain interactions to performance of a wind-farm by studying a multi-turbine wind-farm layout under different terrains. The results on interaction of terrain and vortex has shown a much faster decay of vortex for complex terrain compared to a flatter-terrain. The potential reasons identified explaining the observation are (a) formation of secondary vortices in flow and its interaction with the primary vortex and (b) enhanced vorticity diffusion due to increased terrain-induced turbulence. The implications of

  9. Trailing edge devices to improve performance and increase lifetime of wind-electric water pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Vick, B.D.; Clark, R.N. [USDA-Agricultural Research Service, Bushland, TX (United States)

    1996-12-31

    Trailing edge flaps were applied to the blades of a 10 kW wind turbine used for water pumping to try to improve the performance and decrease the structural fatigue on the wind turbine. Most small wind turbines (10 kW and below) use furling (rotor turns out of wind similar to a mechanical windmill) to protect the wind turbine from overspeed during high winds. Some small wind turbines, however, do not furl soon enough to keep the wind turbine from being off line part of the time in moderately high wind speeds (10 - 16 m/s). As a result, the load is disconnected and no water is pumped at moderately high wind speeds. When the turbine is offline, the frequency increases rapidly often causing excessive vibration of the wind turbine and tower components. The furling wind speed could possibly be decreased by increasing the offset between the tower centerline and the rotor centerline, but would be a major and potentially expensive retrofit. Trailing edge flaps (TEF) were used as a quick inexpensive method to try to reduce the furling wind speed and increase the on time by reducing the rotor RPM. One TEF configuration improved the water pumping performance at moderately high wind speeds, but degraded the pumping performance at low wind speeds which resulted in little change in daily water volume. The other TEF configuration differed very little from the no flap configuration. Both TEF configurations however, reduced the rotor RPM in high wind conditions. The TEF, did not reduce the rotor RPM by lowering the furling wind speed as hoped, but apparently did so by increasing the drag which also reduced the volume of water pumped at the lower wind speeds. 6 refs., 9 figs.

  10. A Flywheel Energy Storage System Based on a Doubly Fed Induction Machine and Battery for Microgrid Control

    Directory of Open Access Journals (Sweden)

    Thai-Thanh Nguyen

    2015-06-01

    Full Text Available Microgrids are eco-friendly power systems because they use renewable sources such as solar and wind power as the main power source. However, the stochastic nature of wind and solar power is a considerable challenge for the efficient operation of microgrids. Microgrid operations have to satisfy quality requirements in terms of the frequency and voltage. To overcome these problems, energy storage systems for short- and long-term storage are used with microgrids. Recently, the use of short-term energy storage systems such as flywheels has attracted significant interest as a potential solution to this problem. Conventional flywheel energy storage systems exhibit only one control mode during operation: either smoothing wind power control or frequency control. In this paper, we propose a new flywheel energy storage system based on a doubly fed induction machine and a battery for use with microgrids. The new flywheel energy storage system can be used not only to mitigate wind power fluctuations, but also to control the frequency as well as the voltage of the microgrid during islanded operation. The performance of the proposed flywheel energy storage system is investigated through various simulations using MATLAB/Simulink software. In addition, a conventional flywheel energy storage system based on a doubly fed induction machine is simulated and its performance compared with that of the proposed one.

  11. Performance Evaluation of a Modular Design of Wind Tower with Wetted Surfaces

    Directory of Open Access Journals (Sweden)

    Sajad M.R. Khani

    2017-06-01

    Full Text Available Wind towers or wind catchers, as passive cooling systems, can provide natural ventilation in buildings located in hot, arid regions. These natural cooling systems can provide thermal comfort for the building inhabitants throughout the warm months. In this paper, a modular design of a wind tower is introduced. The design, called a modular wind tower with wetted surfaces, was investigated experimentally and analytically. To determine the performance of the wind tower, air temperature, relative humidity (RH and air velocity were measured at different points. Measurements were carried out when the wind speed was zero. The experimental results were compared with the analytical ones. The results illustrated that the modular wind tower can decrease the air temperature significantly and increase the relative humidity of airflow into the building. The average differences for air temperature and air relative humidity between ambient air and air exiting from the wind tower were approximately 10 °C and 40%, respectively. The main advantage of the proposed wind tower is that it is a modular design that can reduce the cost of wind tower construction.

  12. Wind Turbine Acoustics

    Science.gov (United States)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    2009-01-01

    Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

  13. A comparative investigation of three PM-less MW power range wind generator topologies

    DEFF Research Database (Denmark)

    Bratiloveanu, Catalin-Rauti; Traian Cosmin Anghelus, Dumitru; Boldea, I.

    2012-01-01

    As the wind energy penetration range increases steadily and the high energy PM costs are rising dramatically, PM-less large power wind generators with high performance are needed. Apart from extending the range of cage rotor induction generators, doubly-fed induction generators and dc excited...... investigates by quasi 2D-FEM two dc stator polarized (to increase machine side PWM converter voltage utilization, that is to reduce peak kVA ratings and costs of the machine side PWM converter) directly-driven switched reluctance generators (one with circumferential field and one with transverse flux (with...... heteropolar-rotor (standard) synchronous generators, especially for direct drives (very low speed) and multibrid (with single stage transmission (5/1-8/1 ratio)), new topologies have to be investigated to reduce initial costs and weights for high enough efficiency and energy annual yield. The present paper...

  14. Experimental studies of Savonius wind turbines with variations sizes and fin numbers towards performance

    Science.gov (United States)

    Utomo, Ilham Satrio; Tjahjana, Dominicus Danardono Dwi Prija; Hadi, Syamsul

    2018-02-01

    The use of renewable energy in Indonesia is still low. Especially the use of wind energy. Wind turbine Savonius is one turbine that can work with low wind speed. However, Savonius wind turbines still have low efficiency. Therefore it is necessary to modify. Modifications by using the fin are expected to increase the positive drag force by creating a flow that can enter the overlap ratio of the gap. This research was conducted using experimental approach scheme. Parameters generated from the experiment include: power generator, power coefficient, torque coefficient. The experimental data will be collected by variation of fin area, horizontal finning, at wind speed 3 m/s - 4,85 m/s. Experimental results show that with the addition of fin can improve the performance of wind turbine Savonius 11%, and by using the diameter of 115 mm fin is able to provide maximum performance in wind turbine Savonius.

  15. APPLICATION OF THE PERFORMANCE SELECTION INDEX METHOD FOR SOLVING MACHINING MCDM PROBLEMS

    Directory of Open Access Journals (Sweden)

    Dušan Petković

    2017-04-01

    Full Text Available Complex nature of machining processes requires the use of different methods and techniques for process optimization. Over the past few years a number of different optimization methods have been proposed for solving continuous machining optimization problems. In manufacturing environment, engineers are also facing a number of discrete machining optimization problems. In order to help decision makers in solving this type of optimization problems a number of multi criteria decision making (MCDM methods have been proposed. This paper introduces the use of an almost unexplored MCDM method, i.e. performance selection index (PSI method for solving machining MCDM problems. The main motivation for using the PSI method is that it is not necessary to determine criteria weights as in other MCDM methods. Applicability and effectiveness of the PSI method have been demonstrated while solving two case studies dealing with machinability of materials and selection of the most suitable cutting fluid for the given machining application. The obtained rankings have good correlation with those derived by the past researchers using other MCDM methods which validate the usefulness of this method for solving machining MCDM problems.

  16. Small wind planning and building successful installations

    CERN Document Server

    Clark, Nolan

    2013-01-01

    This book provides a cohesive guide to achieving successful small wind installations. It is a comprehensive information resource from one of the world's most experienced small wind professionals, covering all the key issues for small wind system development, from site and machine selection to international standards compliance. Engineers who are tasked with planning and developing these small wind systems, from choosing the best site and accurately estimating likely power output to obtaining proper permitting and troubleshooting operational inefficiencies, will find this book an ess

  17. Tuning of the PI Controller Parameters of a PMSG Wind Turbine to Improve Control Performance under Various Wind Speeds

    OpenAIRE

    Yun-Su Kim; Il-Yop Chung; Seung-Il Moon

    2015-01-01

    This paper presents a method to seek the PI controller parameters of a PMSG wind turbine to improve control performance. Since operating conditions vary with the wind speed, therefore the PI controller parameters should be determined as a function of the wind speed. Small-signal modeling of a PMSG WT is implemented to analyze the stability under various operating conditions and with eigenvalues obtained from the small-signal model of the PMSG WT, which are coordinated by adjusting the PI con...

  18. Significant improvements of electrical discharge machining performance by step-by-step updated adaptive control laws

    Science.gov (United States)

    Zhou, Ming; Wu, Jianyang; Xu, Xiaoyi; Mu, Xin; Dou, Yunping

    2018-02-01

    In order to obtain improved electrical discharge machining (EDM) performance, we have dedicated more than a decade to correcting one essential EDM defect, the weak stability of the machining, by developing adaptive control systems. The instabilities of machining are mainly caused by complicated disturbances in discharging. To counteract the effects from the disturbances on machining, we theoretically developed three control laws from minimum variance (MV) control law to minimum variance and pole placements coupled (MVPPC) control law and then to a two-step-ahead prediction (TP) control law. Based on real-time estimation of EDM process model parameters and measured ratio of arcing pulses which is also called gap state, electrode discharging cycle was directly and adaptively tuned so that a stable machining could be achieved. To this end, we not only theoretically provide three proved control laws for a developed EDM adaptive control system, but also practically proved the TP control law to be the best in dealing with machining instability and machining efficiency though the MVPPC control law provided much better EDM performance than the MV control law. It was also shown that the TP control law also provided a burn free machining.

  19. Darrieus wind-turbine and pump performance for low-lift irrigation pumping

    Science.gov (United States)

    Hagen, L. J.; Sharif, M.

    1981-10-01

    In the Great Plains about 15 percent of the irrigation water pumped on farms comes from surface water sources; for the United States as a whole, the figure is about 22 percent. Because of forecast fuel shortages, there is a need to develop alternative energy sources such as wind power for surface water pumping. Specific objectives of this investigation were to: design and assemble a prototype wind powered pumping system for low lift irrigation pumping; determine performance of the prototype system; design and test an irrigation system using the wind powered prototype in a design and test an farm application; and determine the size combinations of wind turbines, tailwater pits, and temporary storage reservoirs needed for successful farm application of wind powered tailwater pumping systems in western Kansas. The power source selected was a two bladed, 6 m diameter, 9 m tall Darrieus vertical axis wind turbine with 0.10 solidity and 36.1 M(2) swept area.

  20. Technology Performance Report: Duke Energy Notrees Wind Storage Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Wehner, Jeff [Duke Energy Renewables, Charlotte, NC (United States); Mohler, David [Duke Energy Renewables, Charlotte, NC (United States); Gibson, Stuart [Duke Energy Renewables, Charlotte, NC (United States); Clanin, Jason [Duke Energy Renewables, Charlotte, NC (United States); Faris, Don [Duke Energy Renewables, Charlotte, NC (United States); Hooker, Kevin [Duke Energy Renewables, Charlotte, NC (United States); Rowand, Michael [Duke Energy Renewables, Charlotte, NC (United States)

    2015-11-01

    Duke Energy Renewables owns and operates the Notrees Wind Farm in west Texas’s Ector and Winkler counties. The wind farm, which was commissioned in April 2009, has a total capacity of 152.6 MW generated by 55 Vestas V82 turbines, one Vestas 1-V90 experimental turbine, and 40 GE 1.5-MW turbines. The Vestas V82 turbines have a generating capacity of 1.65 MW each, the Vestas V90 turbine has a generating capacity of 1.86 MW, and the GE turbines have a generating capacity of 1.5 MW each. The objective of the Notrees Wind Storage Demonstration Project is to validate that energy storage increases the value and practical application of intermittent wind generation and is commercially viable at utility scale. The project incorporates both new and existing technologies and techniques to evaluate the performance and potential of wind energy storage. In addition, it could serve as a model for others to adopt and replicate. Wind power resources are expected to play a significant part in reducing greenhouse gas emissions from electric power generation by 2030. However, the large variability and intermittent nature of wind presents a barrier to integrating it within electric markets, particularly when competing against conventional generation that is more reliable. In addition, wind power production often peaks at night or other times when demand and electricity prices are lowest. Energy storage systems can overcome those barriers and enable wind to become a valuable asset and equal competitor to conventional fossil fuel generation.

  1. Effect of wind speed on performance of a solar-pv array

    Science.gov (United States)

    Thousands of solar photovoltaic (PV) arrays have been installed over the past few years, but the effect of wind speed on the predicted performance of PV arrays is not usually considered by installers. An increase in wind speed will cool the PV array, and the electrical power of the PV modules will ...

  2. Denmark leads in wind energy

    International Nuclear Information System (INIS)

    Aamand, Rene

    1997-01-01

    With an engineering background, Danish manufacturers used a ''bottom-up strategy'' to beat the competition. They start with small-scale 55kW wind turbines, and today offer the MW-sized machines. (author)

  3. Frequency Dependent PD-pulse Distortion in Rotating Machines

    DEFF Research Database (Denmark)

    Holbøll, Joachim T.; Henriksen, Mogens

    1996-01-01

    at the machine terminals. The results show a variation of the attenuation of the discharge pulses inside the machine of about 20 dB highest for pulses from the far end, i.e. the neutral point. The capability of exact localization of the discharges in the winding gives a correct measure of the range...... of the current transformer based detection method, when being applied to rotating machines. The results are discussed with regard to the practical application of PD detection systems on rotating machines, particularly considering aspects of range and applicability of systems in the HF ranges...

  4. Design and analysis of a direct-drive wind power generator with ultra-high torque density

    Science.gov (United States)

    Jian, Linni; Shi, Yujun; Wei, Jin; Zheng, Yanchong

    2015-05-01

    In order to get rid of the nuisances caused by mechanical gearboxes, generators with low rated speed, which can be directly connected to wind turbines, are attracting increasing attention. The purpose of this paper is to propose a new direct-drive wind power generator (DWPG), which can offer ultra-high torque density. First, magnetic gear (MG) is integrated to achieve non-contact torque transmission and speed variation. Second, armature windings are engaged to achieve electromechanical energy conversion. Interior permanent magnet (PM) design on the inner rotor is adopted to boost the torque transmission capability of the integrated MG. Nevertheless, due to lack of back iron on the stator, the proposed generator does not exhibit prominent salient feature, which usually exists in traditional interior PM (IPM) machines. This makes it with good controllability and high power factor as the surface-mounted permanent magnet machines. The performance is analyzed using finite element method. Investigation on the magnetic field harmonics demonstrates that the permanent-magnetic torque offered by the MG can work together with the electromagnetic torque offered by the armature windings to balance the driving torque captured by the wind turbine. This allows the proposed generator having the potential to offer even higher torque density than its integrated MG.

  5. Effectiveness of Hamstring Knee Rehabilitation Exercise Performed in Training Machine vs. Elastic Resistance Electromyography Evaluation Study

    DEFF Research Database (Denmark)

    Jakobsen, M. D.; Sundstrup, E.; Andersen, C. H.

    2014-01-01

    Objective The aim of this study was to evaluate muscle activity during hamstring rehabilitation exercises performed in training machine compared with elastic resistance. Design Six women and 13 men aged 28-67 yrs participated in a crossover study. Electromyographic (EMG) activity was recorded...... inclinometers. Results Training machines and elastic resistance showed similar high levels of muscle activity (biceps femoris and semitendinosus peak normalized EMG >80%). EMG during the concentric phase was higher than during the eccentric phase regardless of exercise and muscle. However, compared with machine.......001) during hamstring curl performed with elastic resistance (7.58 +/- 0.08) compared with hamstring curl performed in a machine (5.92 +/- 0.03). Conclusions Hamstring rehabilitation exercise performed with elastic resistance induces similar peak hamstring muscle activity but slightly lower EMG values at more...

  6. 2015 wind energy observatory. Analysis of market, jobs and future of the wind energy sector in France

    International Nuclear Information System (INIS)

    Perot, Olivier; Autier, Emmanuel

    2015-11-01

    This Power Point presentation proposes graphs, figures, tables and comments on the status and evolution of jobs in the wind energy sector (a growing sector, analysis of job locations), of the wind energy market (assessment of a growing market, dynamic French regions, competitive context, evolution of technologies with higher machines, larger wind farms and a growing production), and on the future of wind energy (a growing number of training courses, an active R and D all over the country, a structuring sector). Sheets presenting actors per categories, and maps of regional activity location are provided in appendix

  7. Axial flux permanent magnet brushless machines

    CERN Document Server

    Gieras, Jacek F; Kamper, Maarten J

    2008-01-01

    Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. They are being increasingly used in consumer electronics, public life, instrumentation and automation system, clinical engineering, industrial electromechanical drives, automobile manufacturing industry, electric and hybrid electric vehicles, marine vessels and toys. They are also used in more electric aircrafts and many other applications on larger scale. New applications have also emerged in distributed generation systems (wind turbine generators

  8. The French wind fleet and its impacts on avifauna. Study of mortality follow-ups performed in France from 1997 to 2015. June 2017 - Updated in September 2017 - LPO France

    International Nuclear Information System (INIS)

    Marx, Geoffroy

    2017-06-01

    The present French policy for energy transition comprises a contribution to the struggle against climate change and to the protection of the environment, notably based on a reduction of greenhouse gas emissions through a decrease of energy consumption (notably fossil energies) and a development of renewable energies, notably ground-based and offshore wind energy. But wind turbines have a potential impact on biodiversity, particularly habitats and flying vertebrates. As the number of wind turbines is to strongly increase, this report proposes a study of bird mortality directly due to collisions with wind turbines, and recommendations for a better environmental integration of ground-based wind farms. Illustrated by figures and tables, the report first proposes a presentation of the French wind turbine fleet (evolution, farm size, machine size, comparison with other countries, distribution on the French territory and within areas of special protection or ZPS). It describes various follow-up studies and data, and outlines their weaknesses and limitations. It reports an analysis of found carcasses, of impacted species, and of species exhibiting no mortality. It proposes an assessment of bird mortality, and discusses impact factors (machine size, distribution in time of carcass discoveries, habitat type, vicinity of ZPS)

  9. Influence of tooth position on wind instrumentalists' performance and embouchure comfort : A systematic review.

    Science.gov (United States)

    van der Weijden, F N; Kuitert, R B; Berkhout, F R U; van der Weijden, G A

    2018-05-01

    To systematically search the scientific literature concerning the influence of tooth position on wind instrumentalists' performance and embouchure comfort. The PubMed, Cochrane, and Embase databases were searched up to November 2017. The main orthodontic journals were searched for papers older than the inception date of PubMed. Grey literature was sought via Google Scholar. Eligible studies were critically appraised and analysed. The searches retrieved 54 papers. Only two met the inclusion criteria. Searching the orthodontic journals and Google Scholar resulted in two additional eligible studies. All four studies had a cross-sectional design. The sample sizes ranged from 20-100 participants, varying from children to professional musicians. Because of a large heterogeneity in outcome variables, no meta-analysis could be performed. Descriptive analysis shows that there are indications that tooth irregularities have a negative influence on embouchure comfort and performance of a wind instrument player. A large overjet may impede the embouchure of brass musicians and may have a negative influence on trumpet player performance. A wide jaw form seems more beneficial to trumpet player performance than a small jaw form. Furthermore, players of all types of wind instruments can experience embouchure difficulties from extreme spacing or an open bite. Tooth position can influence musical performance and embouchure comfort of wind instrumentalists. A Class I relationship without malocclusion seems appropriate for every type of wind instrument. The more extreme the malocclusion, the greater the interference with wind instrumentalists' performance and embouchure comfort. Evidence however is limited.

  10. FUZZY LOGIC BASED INTELLIGENT CONTROL OF A VARIABLE SPEED CAGE MACHINE WIND GENERATION SYSTEM

    Science.gov (United States)

    The paper describes a variable-speed wind generation system where fuzzy logic principles are used to optimize efficiency and enhance performance control. A squirrel cage induction generator feeds the power to a double-sided pulse width modulated converter system which either pump...

  11. First electrical tests on a machine with an AC superconducting stator winding

    International Nuclear Information System (INIS)

    Brunet, Y.; Tixador, P.; Laumond, Y.; Sabrie, J.L.

    1988-01-01

    A three phase superconducting stator winding has been built using a low losses NbTi wire under 50 Hz varying magnetic field and current. It has first been necessary to design an horizontal helium cryostat with fiber-glass composites to avoid the permanent eddy-current losses of the rotating magnetic fields. The liquid helium vessel, containing the armature, is dismountable. The cryostat is 900 mm long and the rotor bore has a diameter of 180 mm. The windings are wounded on five concentric fiber glass cylinders with a thin impregnation of an epoxy film adhesive. The first electrical tests have been performed using a normal iron rotor inside the superconducting stator. No load and permanent tests have been achieved up to a power of 13 kVA. The 18,5 kVA predicted have not been reached because of the present inductor, not yet superconducting

  12. STUDY OF TRANSIENT AND STATIONARY OPERATION MODES OF SYNCHRONOUS SYSTEM CONSISTING IN TWO MACHINES

    Directory of Open Access Journals (Sweden)

    V. S. Safaryan

    2017-01-01

    Full Text Available The solution of the problem of reliable functioning of an electric power system (EPS in steady-state and transient regimes, prevention of EPS transition into asynchronous regime, maintenance and restoration of stability of post-emergency processes is based on formation and realization of mathematical models of an EPS processes. During the functioning of electric power system in asynchronous regime, besides the main frequencies, the currents and voltages include harmonic components, the frequencies of which are multiple of the difference of main frequencies. At the two-frequency asynchronous regime the electric power system is being made equivalent in a form of a two-machine system, functioning for a generalized load. In the article mathematical models of transient process of a two-machine system in natural form and in d–q coordinate system are presented. The mathematical model of two-machine system is considered in case of two windings of excitement at the rotors. Also, in the article varieties of mathematical models of EPS transient regimes (trivial, simple, complete are presented. Transient process of a synchronous two-machine system is described by the complete model. The quality of transient processes of a synchronous machine depends on the number of rotor excitation windings. When there are two excitation windings on the rotor (dual system of excitation, the mathematical model of electromagnetic transient processes of a synchronous machine is represented in a complex form, i.e. in coordinate system d, q, the current of rotor being represented by a generalized vector. In asynchronous operation of a synchronous two-machine system with two excitation windings on the rotor the current and voltage systems include only harmonics of two frequencies. The mathematical model of synchronous steady-state process of a two-machine system is also provided, and the steady-state regimes with different structures of initial information are considered.

  13. Electric Generators and their Control for Large Wind Turbines

    DEFF Research Database (Denmark)

    Boldea, Ion; Tutelea, Lucian; Rallabandi, Vandana

    2017-01-01

    induction generator, the cage rotor induction generator, and the synchronous generator with DC or permanent magnet excitation. The operating principle, performance, optimal design, and the modeling and control of the machine-side converter for each kind of generator are adressed and evaluated. In view......The electric generator and its power electronics interface for wind turbines (WTs) have evolved rapidly toward higher reliability and reduced cost of energy in the last 40 years. This chapter describes the up-to-date electric generators existing in the wind power industry, namely, the doubly fed...... of the fact that individual power rating of WTs has increased to around 10 MW, generator design and control technologies required to reach this power rating are discussed....

  14. A Comparison of the Performance of Advanced Statistical Techniques for the Refinement of Day-ahead and Longer NWP-based Wind Power Forecasts

    Science.gov (United States)

    Zack, J. W.

    2015-12-01

    Predictions from Numerical Weather Prediction (NWP) models are the foundation for wind power forecasts for day-ahead and longer forecast horizons. The NWP models directly produce three-dimensional wind forecasts on their respective computational grids. These can be interpolated to the location and time of interest. However, these direct predictions typically contain significant systematic errors ("biases"). This is due to a variety of factors including the limited space-time resolution of the NWP models and shortcomings in the model's representation of physical processes. It has become common practice to attempt to improve the raw NWP forecasts by statistically adjusting them through a procedure that is widely known as Model Output Statistics (MOS). The challenge is to identify complex patterns of systematic errors and then use this knowledge to adjust the NWP predictions. The MOS-based improvements are the basis for much of the value added by commercial wind power forecast providers. There are an enormous number of statistical approaches that can be used to generate the MOS adjustments to the raw NWP forecasts. In order to obtain insight into the potential value of some of the newer and more sophisticated statistical techniques often referred to as "machine learning methods" a MOS-method comparison experiment has been performed for wind power generation facilities in 6 wind resource areas of California. The underlying NWP models that provided the raw forecasts were the two primary operational models of the US National Weather Service: the GFS and NAM models. The focus was on 1- and 2-day ahead forecasts of the hourly wind-based generation. The statistical methods evaluated included: (1) screening multiple linear regression, which served as a baseline method, (2) artificial neural networks, (3) a decision-tree approach called random forests, (4) gradient boosted regression based upon an decision-tree algorithm, (5) support vector regression and (6) analog ensemble

  15. Robust, Gain-Scheduled Control of Wind Turbines

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck

    Wind turbines are today large and efficient machines, which are combined into wind farms operating on par with conventional power plants. When looking back, this is significantly different from the status only a few years ago, when wind turbines were sold mainly to private people. This change...... in turbine owners has resulted in a new focus on operational reliability instead of turbine size. This research deals with investigating model-based gain-scheduling control of wind turbines by use of linear parameter varying (LPV) methods. The numerical challenges grow quickly with the model size...

  16. A control system for and a method of controlling a superconductive rotating electrical machine

    DEFF Research Database (Denmark)

    2014-01-01

    This invention relates to a method of controlling and a control system (100) for a superconductive rotating electric machine (200) comprising at least one superconductive winding (102; 103), where the control system (100) is adapted to control a power unit (101) supplying during use the at least...... or more actual values (110, 111)of one or more parameters for a given superconductive winding (102; 103), each parameter representing a physical condition of the given superconductive winding (102; 103), and to dynamically derive one or more electrical current values to be maintained in the given...... superconductive winding (102; 103) by the power unit (101) where the one or more electrical current values is/are derived taking into account the received one or more actual values (110, 111). In this way,greater flexibility and more precise control of the performance of the superconducting rotating electrical...

  17. (House Municipal School wind energy system: equipment performance). Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1985-05-14

    The performance of a Skyhawk horizontal axis wind system with a 3-blade, 15-ft upwind rotor is evaluated. The wind system was placed at the House Municipal School. The school is located between Tucumcari and Clovis, New Mexico and has an annual wind regime of 12 mi/h at a height of 33 ft. It was operated for 26 months and during that time has been out of service, due to breakdowns, 13 months. When the Skyhawk was operational, it generated between 100 and 700 kilowatt-hrs per month.

  18. Contribution to the design and the control of synchronous double excitation machines: hybrid vehicle application; Contribution a la conception et a la commande des machines synchrones a double excitation: application au vehicule hybride

    Energy Technology Data Exchange (ETDEWEB)

    Amara, Y

    2001-12-01

    Double excitation machines are synchronous machines where two excitation circuits coexist: one with permanent magnets and the other with windings. This study shows that double excitation allows to combine the advantages of synchronous machines with winded inductor with those of permanent magnet machines. This concept allows a better dimensioning of the converter-machine set and a better energy management. In order to allow the operation of permanent magnet machines over a wide range of speeds, it is necessary to have a magnetic reaction of the induced circuit of the same order than the excitation flux. On the other hand, the power factor is weaker and the power supply converter is over-dimensioned. The double excitation allows the permanent magnet machines to work over a large speed range with a better power factor, even when the magnetic reaction of the induced circuit is relatively weak with respect to the excitation flux. (J.S.)

  19. Modelling and Analysis of Radial Flux Surface Mounted Direct-Driven PMSG in Small Scale Wind Turbine

    Directory of Open Access Journals (Sweden)

    Theint Zar Htet

    2017-11-01

    Full Text Available This paper presents the modelling and analysis of permanent magnet synchronous generator (PMSG which are used in direct driven small scale wind turbines. The 3 kW PM generator which is driven directly without gear system is analyzed by Ansoft Maxwell 2D RMxprt. The performance analysis of generator includes the cogging torque in two teeth, induced coil voltages under load, winding current under load, airgap flux density distribution and so on. The modelling analysis is based on the 2D finite element techniques. In an electrical machine, an accurate determination of the geometry parameters is a vital role. The proper performance results of 3kW PMSG in small scale wind turbine can be seen in this paper.

  20. Investigation of transient models and performances for a doubly fed wind turbine under a grid fault

    DEFF Research Database (Denmark)

    Wang, M.; Zhao, B.; Li, H.

    2011-01-01

    fed induction generator (DFIG), the assessments of the impact on the electrical transient performances were investigated for the doubly fed wind turbine with different representations of wind turbine drive-train dynamics models, different initial operational conditions and different active crowbar...... crowbar on the transient performances of the doubly fed wind turbine were also investigated, with the possible reasonable trip time of crowbar. The investigation have shown that the transient performances are closely correlated with the wind turbine drive train models, initial operational conditions, key...

  1. Project appraisal for small and medium size wind energy installation: The Italian wind energy policy effects

    International Nuclear Information System (INIS)

    Fera, M.; Iannone, R.; Macchiaroli, R.; Miranda, S.; Schiraldi, M.M.

    2014-01-01

    In the last few years, the distributed energy production from small wind turbines (i.e.<200 kWp) has developed into a relevant business opportunity for different investors in Italy. The market, especially in Italy, has rapidly grown, achieving 9 MWp only in 2011, with an increase from 1.5 MW in 2009 to 13.3 MW at the end of 2011. This paper reports the results of a case study on the installation of several small wind turbines. It aims to provide an analysis of the conditions in Italy that make it possible to install these machines and offer a reliable reference for designing, planning, and controlling small wind turbine projects while focusing on the strategic variables of time, cost, and quality used by typical enterprises in the investment projects. The results are relevant to investors as well as engineering, procurement, and construction companies involved in this new sector, which must understand Italy’s renewable energy policy and its effects in practice. Moreover, certain national energy policy conclusions are reported and discussed in this paper. To properly study the sector, the data on time, cost and quality are analysed using typical project management tools. - Highlights: • Focus on the Italian wind energy sector. • Analysis of Italian policy effects. • Focus on small/medium size wind energy machines

  2. Wind turbine performance: Methods and criteria for reliability of measured power curves

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.A. [Advanced Wind Turbines Inc., Seattle, WA (United States)

    1996-12-31

    In order to evaluate the performance of prototype turbines, and to quantify incremental changes in performance through field testing, Advanced Wind Turbines (AWT) has been developing methods and requirements for power curve measurement. In this paper, field test data is used to illustrate several issues and trends which have resulted from this work. Averaging and binning processes, data hours per wind-speed bin, wind turbulence levels, and anemometry methods are all shown to have significant impacts on the resulting power curves. Criteria are given by which the AWT power curves show a high degree of repeatability, and these criteria are compared and contrasted with current published standards for power curve measurement. 6 refs., 5 figs., 5 tabs.

  3. Design of low noise airfoil with high aerodynamic performance for use on small wind turbines

    Institute of Scientific and Technical Information of China (English)

    Taehyung; KIM; Seungmin; LEE; Hogeon; KIM; Soogab; LEE

    2010-01-01

    Wind power is one of the most reliable renewable energy sources and internationally installed capacity is increasing radically every year.Although wind power has been favored by the public in general,the problem with the impact of wind turbine noise on people living in the vicinity of the turbines has been increased.Low noise wind turbine design is becoming more and more important as noise is spreading more adverse effect of wind turbine to public.This paper demonstrates the design of 10 kW class wind turbines,each of three blades,a rotor diameter 6.4 m,a rated rotating speed 200 r/min and a rated wind speed 10 m/s.The optimized airfoil is dedicated for the 75% spanwise position because the dominant source of a wind turbine blade is trailing edge noise from the outer 25% of the blade.Numerical computations are performed for incompressible flow and for Mach number at 0.145 and for Reynolds numbers at 1.02×106 with a lift performance,which is resistant to surface contamination and turbulence intensity.The objectives in the design process are to reduce noise emission,while sustaining high aerodynamic efficiency.Dominant broadband noise sources are predicted by semi-empirical formulas composed of the groundwork by Brooks et al.and Lowson associated with typical wind turbine operation conditions.During the airfoil redesign process,the aerodynamic performance is analyzed to reduce the wind turbine power loss.The results obtained from the design process show that the design method is capable of designing airfoils with reduced noise using a commercial 10 kW class wind turbine blade airfoil as a basis.Therefore,the new optimized airfoil showing 2.9 dB reductions of total sound pressure level(SPL) and higher aerodynamic performance are achieved.

  4. The aerodynamic performance of the water pumping wind turbine for Bangladesh

    International Nuclear Information System (INIS)

    Ahmed, S.; Islam, M.Q.

    2004-01-01

    In order to examine the feasibility of wind energy for water pumping in Bangladesh, an experimental investigation of performance characteristics of horizontal axis wind turbines has been conducted. Wind characteristics of various regions of Bangladesh have been analysed and hence a compatible design of horizontal axis wind turbine applicable to the pump has been suggested. The wind data collected by the meteorological department of Bangladesh for a period 16 years of 20 stations at different heights between 5m and 10m have been converted to 20m hub-height using power law. From these data monthly average speeds have been calculated. It is observed that for few regions of Bangladesh, there is reasonable wind speed available throughout the year to extract useful power. Considering a particular prospective region of Bangladesh a wind turbine has been designed for water pumping. The design incorporates the generalized procedure for determination of rotor and pump sizes. Thus it can be also used for any other region as well. In this paper, a generalized design for Bangladesh, a nomogram and an empirical relation have been developed for the rotor and the pump size for a particular region of Bangladesh.(author)

  5. Machining of high performance workpiece materials with CBN coated cutting tools

    International Nuclear Information System (INIS)

    Uhlmann, E.; Fuentes, J.A. Oyanedel; Keunecke, M.

    2009-01-01

    The machining of high performance workpiece materials requires significantly harder cutting materials. In hard machining, the early tool wear occurs due to high process forces and temperatures. The hardest known material is the diamond, but steel materials cannot be machined with diamond tools because of the reactivity of iron with carbon. Cubic boron nitride (cBN) is the second hardest of all known materials. The supply of such PcBN indexable inserts, which are only geometrically simple and available, requires several work procedures and is cost-intensive. The development of a cBN coating for cutting tools, combine the advantages of a thin film system and of cBN. Flexible cemented carbide tools, in respect to the geometry can be coated. The cBN films with a thickness of up to 2 μm on cemented carbide substrates show excellent mechanical and physical properties. This paper describes the results of the machining of various workpiece materials in turning and milling operations regarding the tool life, resultant cutting force components and workpiece surface roughness. In turning tests of Inconel 718 and milling tests of chrome steel the high potential of cBN coatings for dry machining was proven. The results of the experiments were compared with common used tool coatings for the hard machining. Additionally, the wear mechanisms adhesion, abrasion, surface fatigue and tribo-oxidation were researched in model wear experiments.

  6. Intraoperative performance and postoperative outcome comparison of longitudinal, torsional, and transversal phacoemulsification machines.

    Science.gov (United States)

    Christakis, Panos G; Braga-Mele, Rosa M

    2012-02-01

    To compare the intraoperative performance and postoperative outcomes of 3 phacoemulsification machines that use different modes. Kensington Eye Institute, Toronto, Ontario, Canada. Comparative case series. This chart and video review comprised consecutive eligible patients who had phacoemulsification by the same surgeon using a Whitestar Signature Ellips-FX (transversal), Infiniti-Ozil-IP (torsional), or Stellaris (longitudinal) machine. The review included 98 patients. Baseline characteristics in the groups were similar; the mean nuclear sclerosis grade was 2.0 ± 0.8. There were no significant intraoperative complications. The torsional machine averaged less phacoemulsification needle time (83 ± 33 seconds) than the transversal (99 ± 40 seconds; P=.21) or longitudinal (110 ± 45 seconds; P=.02) machines; the difference was accentuated in cases with high-grade nuclear sclerosis. The torsional machine had less chatter and better followability than the transversal or longitudinal machines (P<.001). The torsional and longitudinal machines had better anterior chamber stability than the transversal machine (P<.001). Postoperatively, the torsional machine yielded less central corneal edema than the transversal (P<.001) and longitudinal (P=.04) machines, corresponding to a smaller increase in mean corneal thickness (torsional 5%, transversal 10%, longitudinal 12%; P=.04). Also, the torsional machine had better 1-day postoperative visual acuities (P<.001). All 3 phacoemulsification machines were effective with no significant intraoperative complications. The torsional machine outperformed the transversal and longitudinal machines, with a lower mean needle time, less chatter, and improved followability. This corresponded to less corneal edema 1 day postoperatively and better visual acuity. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Performance assessment of Portuguese wind farms: Ownership and managerial efficiency

    International Nuclear Information System (INIS)

    Pestana Barros, Carlos; Sequeira Antunes, Olinda

    2011-01-01

    This paper analyzes ownership and unobserved managerial ability as factors affecting the performance of a representative sample of Portuguese wind farms by means of frontier models. These farms are ranked according to their technical efficiency during the period 2004-2008 and homogenous and heterogeneous variables are disentangled in the cost function, which leads us to advise the implementation of common policies as well as policies by segments. Economic implications arising from the study are also considered. - Research highlights: → Wind farms are heterogeneous displaying distinct ownership and managerial characteristics that affect efficiency. → Managerial practices has a positive impact on the efficiency. → Ownership has a positive impact on the efficiency. Large wind farms are more efficient.

  8. Control design and performance analysis of a 6 MW wind turbine-generator

    Science.gov (United States)

    Murdoch, A.; Winkelman, J. R.; Javid, S. H.; Barton, R. S.

    1983-01-01

    This paper discusses an approach to the modeling and performance for the preliminary design phase of a large (6.2 MW) horizontal axis wind turbine generator (WTG). Two control philosophies are presented, both of which are based on linearized models of the WT mechanical and electrical systems. The control designs are compared by showing the performance through detailed non-linear time simulation. The disturbances considered are wind gusts, and electrical faults near the WT terminals.

  9. Program for stator winding leakage inductance determination by FEA

    Directory of Open Access Journals (Sweden)

    Olivian Chiver

    2009-05-01

    Full Text Available This paper presents a program designed by the author in order to determine the stator winding parameters. The program is realized in Visual Basic and, in fact, it is for computer aided design of AC machines. Starting from the design data, based on the classical analytical formulas, geometrical parameters of the stator and the parameters of the stator winding are computed. This program works with a finite elements analysis (FEA software (the one used by the author is MagNet, a product of Infolytica company and according to data obtained after the design calculation, or according to data specified by user (in case of an existing machine, the stator and stator winding are built 3D (three-dimensional. For the same stator, different types of winding can be chosen. After realizing numerical model, by 3D FEA, leakage inductance is determined.

  10. Electronically commutated serial-parallel switching for motor windings

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN

    2012-03-27

    A method and a circuit for controlling an ac machine comprises controlling a full bridge network of commutation switches which are connected between a multiphase voltage source and the phase windings to switch the phase windings between a parallel connection and a series connection while providing commutation discharge paths for electrical current resulting from inductance in the phase windings. This provides extra torque for starting a vehicle from lower battery current.

  11. Design and analysis of full pitch winding and concentrated stator ...

    Indian Academy of Sciences (India)

    magnet machine with flux linkage reversal in the stator concentrated winding. The existing ... Section 7 compares steady state motor ... flux linking the stator winding is sinusoidal, the induced emf is also sinusoidal as shown in figure 3.

  12. Wind Tunnel Aeroacoustic Tests of Six Airfoils for Use on Small Wind Turbines; Period of Performance: August 23, 2002 through March 31, 2004

    Energy Technology Data Exchange (ETDEWEB)

    Oerlemans, S.

    2004-08-01

    The U.S. Department of Energy, working through the National Renewable Energy Laboratory, is engaged in a comprehensive research effort to improve our understanding of wind turbine aeroacoustics. Quiet wind turbines are an inducement to widespread deployment, so the goal of NREL's aeroacoustic research is to develop tools that the U.S. wind industry can use in developing and deploying highly efficient, quiet wind turbines at low wind speed sites. NREL's National Wind Technology Center is implementing a multifaceted approach that includes wind tunnel tests, field tests, and theoretical analyses in direct support of low wind speed turbine development by its industry partners. To that end, wind tunnel aerodynamic tests and aeroacoustic tests have been performed on six airfoils that are candidates for use on small wind turbines. Results are documented in this report.

  13. Energy-efficient electrical machines by new materials. Superconductivity in large electrical machines

    International Nuclear Information System (INIS)

    Frauenhofer, Joachim; Arndt, Tabea; Grundmann, Joern

    2013-01-01

    The implementation of superconducting materials in high-power electrical machines results in significant advantages regarding efficiency, size and dynamic behavior when compared to conventional machines. The application of HTS (high-temperature superconductors) in electrical machines allows significantly higher power densities to be achieved for synchronous machines. In order to gain experience with the new technology, Siemens carried out a series of development projects. A 400 kW model motor for the verification of a concept for the new technology was followed by a 4000 kV A generator as highspeed machine - as well as a low-speed 4000 kW propeller motor with high torque. The 4000 kVA generator is still employed to carry out long-term tests and to check components. Superconducting machines have significantly lower weight and envelope dimensions compared to conventional machines, and for this reason alone, they utilize resources better. At the same time, operating losses are slashed to about half and the efficiency increases. Beyond this, they set themselves apart as a result of their special features in operation, such as high overload capability, stiff alternating load behavior and low noise. HTS machines provide significant advantages where the reduction of footprint, weight and losses or the improved dynamic behavior results in significant improvements of the overall system. Propeller motors and generators,for ships, offshore plants, in wind turbine and hydroelectric plants and in large power stations are just some examples. HTS machines can therefore play a significant role when it comes to efficiently using resources and energy as well as reducing the CO 2 emissions.

  14. Dynamic Performances of Asynchronous Machines | Ubeku ...

    African Journals Online (AJOL)

    The per-phase parameters of a 1.5 hp, 380 V, 50 Hz, 4 poles, 3 phase asynchronous machine used in the simulation were computed with reading obtained from a dc, no-load and blocked rotor tests carried out on the machine in the laboratory. The results obtained from the computer simulations confirmed the capabilities ...

  15. Block-Module Electric Machines of Alternating Current

    Science.gov (United States)

    Zabora, I.

    2018-03-01

    The paper deals with electric machines having active zone based on uniform elements. It presents data on disk-type asynchronous electric motors with short-circuited rotors, where active elements are made by integrated technique that forms modular elements. Photolithography, spraying, stamping of windings, pressing of core and combined methods are utilized as the basic technological approaches of production. The constructions and features of operation for new electric machine - compatible electric machines-transformers are considered. Induction motors are intended for operation in hermetic plants with extreme conditions surrounding gas, steam-to-gas and liquid environment at a high temperature (to several hundred of degrees).

  16. Detection of inter-turn short-circuit at start-up of induction machine based on torque analysis

    Directory of Open Access Journals (Sweden)

    Pietrowski Wojciech

    2017-12-01

    Full Text Available Recently, interest in new diagnostics methods in a field of induction machines was observed. Research presented in the paper shows the diagnostics of induction machine based on torque pulsation, under inter-turn short-circuit, during start-up of a machine. In the paper three numerical techniques were used: finite element analysis, signal analysis and artificial neural networks (ANN. The elaborated numerical model of faulty machine consists of field, circuit and motion equations. Voltage excited supply allowed to determine the torque waveform during start-up. The inter-turn short-circuit was treated as a galvanic connection between two points of the stator winding. The waveforms were calculated for different amounts of shorted-turns from 0 to 55. Due to the non-stationary waveforms a wavelet packet decomposition was used to perform an analysis of the torque. The obtained results of analysis were used as input vector for ANN. The response of the neural network was the number of shorted-turns in the stator winding. Special attention was paid to compare response of general regression neural network (GRNN and multi-layer perceptron neural network (MLP. Based on the results of the research, the efficiency of the developed algorithm can be inferred.

  17. A tubular flux-switching permanent magnet machine

    Science.gov (United States)

    Wang, J.; Wang, W.; Clark, R.; Atallah, K.; Howe, D.

    2008-04-01

    The paper describes a novel tubular, three-phase permanent magnet brushless machine, which combines salient features from both switched reluctance and permanent magnet machine technologies. It has no end windings and zero net radial force and offers a high power density and peak force capability, as well as the potential for low manufacturing cost. It is, therefore, eminently suitable for a variety of applications, ranging from free-piston energy converters to active vehicle suspensions.

  18. Great expectations: large wind turbines

    International Nuclear Information System (INIS)

    De Vries, E.

    2001-01-01

    This article focuses on wind turbine product development, and traces the background to wind turbines from the first generation 1.5 MW machines in 1995-6, plans for the second generation 3-5 MW class turbines to meet the expected boom in offshore wind projects, to the anticipated installation of a 4.5 MW turbine, and offshore wind projects planned for 2000-2002. The switch by the market leader Vestas to variable speed operation in 2000, the new product development and marketing strategy taken by the German Pro + Pro consultancy in their design of a 1.5 MW variable speed pitch control concept, the possible limiting of the size of turbines due to logistical difficulties, opportunities offered by air ships for large turbines, and the commissioning of offshore wind farms are discussed. Details of some 2-5 MW offshore wind turbine design specifications are tabulated

  19. Influence of omni-directional guide vane on the performance of cross-flow rotor for urban wind energy

    Science.gov (United States)

    Wicaksono, Yoga Arob; Tjahjana, Dominicus Danardono Dwi Prija; Hadi, Syamsul

    2018-02-01

    Vertical axis wind turbine like cross-flow rotor have some advantage there are, high self-starting torque, low noise, and high stability; so, it can be installed in the urban area to produce electricity. But, the urban area has poor wind condition, so the cross-flow rotor needs a guide vane to increase its performance. The aim of this study is to determine experimentally the effect of Omni-Directional Guide Vane (ODGV) on the performance of a cross-flow wind turbine. Wind tunnel experiment has been carried out for various configurations. The ODGV was placed around the cross-flow rotor in order to increase ambient wind environment of the wind turbine. The maximum power coefficient is obtained as Cpmax = 0.125 at 60° wind direction. It was 21.46% higher compared to cross-flow wind turbine without ODGV. This result showed that the ODGV able to increase the performance of the cross-flow wind turbine.

  20. Wind farms providing secondary frequency regulation: Evaluating the performance of model-based receding horizon control

    International Nuclear Information System (INIS)

    Shapiro, Carl R.; Meneveau, Charles; Gayme, Dennice F.; Meyers, Johan

    2016-01-01

    We investigate the use of wind farms to provide secondary frequency regulation for a power grid. Our approach uses model-based receding horizon control of a wind farm that is tested using a large eddy simulation (LES) framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and interactions, both of which play an important role in wind farm power production. This controller is implemented in an LES model of an 84-turbine wind farm represented by actuator disk turbine models. Differences between the velocities at each turbine predicted by the wake model and measured in LES are used for closed-loop feedback. The controller is tested on two types of regulation signals, “RegA” and “RegD”, obtained from PJM, an independent system operator in the eastern United States. Composite performance scores, which are used by PJM to qualify plants for regulation, are used to evaluate the performance of the controlled wind farm. Our results demonstrate that the controlled wind farm consistently performs well, passing the qualification threshold for all fastacting RegD signals. For the RegA signal, which changes over slower time scales, the controlled wind farm's average performance surpasses the threshold, but further work is needed to enable the controlled system to achieve qualifying performance all of the time. (paper)

  1. Danish wind turbines: Technical-economic feasibility of commercial models

    International Nuclear Information System (INIS)

    Falchetta, M.

    1992-01-01

    This feasibility study examines the principal technical and economic (investment-manufacturing-installation-operation unit costs, supply and demand) characteristics of wind turbines being commercialized in Denmark. The general configuration of the 150 to 450 kW range machines currently being manufactured can be described as that of a three bladed fibreglass rotor, of from 24 to 35 meters in diameter, and mounted on a tower of from 29 to 41 meters in height. The electrical system consists of one asynchronous generator or a two generator system with a power ratio of 1 to 5 between the two generators. The cost analysis reveals that the Danish wind turbines are competitively priced, with per kWh costs varying from $0. 0675 to $0. 040 for operating wind speeds ranging from 5 to 7 m/sec, and that their overall design and performance characteristics make them suitable for Italian site conditions

  2. Spatio-temporal data analytics for wind energy integration

    CERN Document Server

    Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief presents spatio-temporal data analytics for wind energy integration using stochastic modeling and optimization methods. It explores techniques for efficiently integrating renewable energy generation into bulk power grids. The operational challenges of wind, and its variability are carefully examined. A spatio-temporal analysis approach enables the authors to develop Markov-chain-based short-term forecasts of wind farm power generation. To deal with the wind ramp dynamics, a support vector machine enhanced Markov model is introduced. The stochastic optimization of economic di

  3. A Summary of the Fatigue Properties of Wind Turbine Materials

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND, HERBERT J.

    1999-10-07

    Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. The materials used to construct these machines are subjected to a unique loading spectrum that contains several orders of magnitude more cycles than other fatigue critical structures, e.g., an airplane. To facilitate fatigue designs, a large database of material properties has been generated over the past several years that is specialized to materials typically used in wind turbines. In this paper, I review these fatigue data. Major sections are devoted to the properties developed for wood, metals (primarily aluminum) and fiberglass. Special emphasis is placed on the fiberglass discussion because this material is current the material of choice for wind turbine blades. The paper focuses on the data developed in the U.S., but cites European references that provide important insights.

  4. Reactive power generation in high speed induction machines by continuously occurring space-transients

    Science.gov (United States)

    Laithwaite, E. R.; Kuznetsov, S. B.

    1980-09-01

    A new technique of continuously generating reactive power from the stator of a brushless induction machine is conceived and tested on a 10-kw linear machine and on 35 and 150 rotary cage motors. An auxiliary magnetic wave traveling at rotor speed is artificially created by the space-transient attributable to the asymmetrical stator winding. At least two distinct windings of different pole-pitch must be incorporated. This rotor wave drifts in and out of phase repeatedly with the stator MMF wave proper and the resulting modulation of the airgap flux is used to generate reactive VA apart from that required for magnetization or leakage flux. The VAR generation effect increases with machine size, and leading power factor operation of the entire machine is viable for large industrial motors and power system induction generators.

  5. Fault tolerant operation of switched reluctance machine

    Science.gov (United States)

    Wang, Wei

    The energy crisis and environmental challenges have driven industry towards more energy efficient solutions. With nearly 60% of electricity consumed by various electric machines in industry sector, advancement in the efficiency of the electric drive system is of vital importance. Adjustable speed drive system (ASDS) provides excellent speed regulation and dynamic performance as well as dramatically improved system efficiency compared with conventional motors without electronics drives. Industry has witnessed tremendous grow in ASDS applications not only as a driving force but also as an electric auxiliary system for replacing bulky and low efficiency auxiliary hydraulic and mechanical systems. With the vast penetration of ASDS, its fault tolerant operation capability is more widely recognized as an important feature of drive performance especially for aerospace, automotive applications and other industrial drive applications demanding high reliability. The Switched Reluctance Machine (SRM), a low cost, highly reliable electric machine with fault tolerant operation capability, has drawn substantial attention in the past three decades. Nevertheless, SRM is not free of fault. Certain faults such as converter faults, sensor faults, winding shorts, eccentricity and position sensor faults are commonly shared among all ASDS. In this dissertation, a thorough understanding of various faults and their influence on transient and steady state performance of SRM is developed via simulation and experimental study, providing necessary knowledge for fault detection and post fault management. Lumped parameter models are established for fast real time simulation and drive control. Based on the behavior of the faults, a fault detection scheme is developed for the purpose of fast and reliable fault diagnosis. In order to improve the SRM power and torque capacity under faults, the maximum torque per ampere excitation are conceptualized and validated through theoretical analysis and

  6. CFD Analysis On The Performance Of Wind Turbine With Nozzles

    Directory of Open Access Journals (Sweden)

    Chunkyraj Kh

    2015-08-01

    Full Text Available In this paper an effort has been made in dealing with fluid characteristic that enters a converging nozzle and analysis of the nozzle is carried out using Computational Fluid Dynamics package ANSYS WORKBENCH 14.5. The paper is the continuation of earlier work Analytical and Experimental performance evaluation of Wind turbine with Nozzles. First the CFD analysis will be carried out on nozzle in-front of wind turbine where streamline velocity at the exit volume flow rate in the nozzle and pressure distribution across the nozzle will be studied. Experiments were conducted on the Wind turbine with nozzles and the corresponding power output at different air speed and different size of nozzles were calculated. Different shapes and dimensions with special contours and profiles of nozzles were studied. It was observed that the special contour nozzles have superior outlet velocity and low pressure at nozzle exit the design has maximum Kinetic energy. These indicators conclude that the contraction designed with the new profile is a good enhancing of the nozzle performance.

  7. Calculation of design load for the MOD-5A 7.3 mW wind turbine system

    Science.gov (United States)

    Mirandy, L.; Strain, J. C.

    1995-01-01

    Design loads are presented for the General Electric MOD-SA wind turbine. The MOD-SA system consists of a 400 ft. diameter, upwind, two-bladed, teetered rotor connected to a 7.3 mW variable-speed generator. Fatigue loads are specified in the form of histograms for the 30 year life of the machine, while limit (or maximum) loads have been derived from transient dynamic analysis at critical operating conditions. Loads prediction was accomplished using state of the art aeroelastic analyses developed at General Electric. Features of the primary predictive tool - the Transient Rotor Analysis Code (TRAC) are described in the paper. Key to the load predictions are the following wind models: (1) yearly mean wind distribution; (2) mean wind variations during operation; (3) number of start/shutdown cycles; (4) spatially large gusts; and (5) spatially small gusts (local turbulence). The methods used to develop statistical distributions from load calculations represent an extension of procedures used in past wind programs and are believed to be a significant contribution to Wind Turbine Generator analysis. Test/theory correlations are presented to demonstrate code load predictive capability and to support the wind models used in the analysis. In addition MOD-5A loads are compared with those of existing machines. The MOD-5A design was performed by the General Electric Company, Advanced Energy Program Department, under Contract DEN3-153 with NASA Lewis Research Center and sponsored by the Department of Energy.

  8. Lewis Research Center studies of multiple large wind turbine generators on a utility network

    Science.gov (United States)

    Gilbert, L. J.; Triezenberg, D. M.

    1979-01-01

    A NASA-Lewis program to study the anticipated performance of a wind turbine generator farm on an electric utility network is surveyed. The paper describes the approach of the Lewis Wind Energy Project Office to developing analysis capabilities in the area of wind turbine generator-utility network computer simulations. Attention is given to areas such as, the Lewis Purdue hybrid simulation, an independent stability study, DOE multiunit plant study, and the WEST simulator. Also covered are the Lewis mod-2 simulation including analog simulation of a two wind turbine system and comparison with Boeing simulation results, and gust response of a two machine model. Finally future work to be done is noted and it is concluded that the study shows little interaction between the generators and between the generators and the bus.

  9. Electric power from vertical-axis wind turbines

    Science.gov (United States)

    Touryan, K. J.; Strickland, J. H.; Berg, D. E.

    1987-12-01

    Significant advancements have occurred in vertical axis wind turbine (VAWT) technology for electrical power generation over the last decade; in particular, well-proven aerodynamic and structural analysis codes have been developed for Darrieus-principle wind turbines. Machines of this type have been built by at least three companies, and about 550 units of various designs are currently in service in California wind farms. Attention is presently given to the aerodynamic characteristics, structural dynamics, systems engineering, and energy market-penetration aspects of VAWTs.

  10. Apparatus For Laminating Segmented Core For Electric Machine

    Science.gov (United States)

    Lawrence, Robert Anthony; Stabel, Gerald R

    2003-06-17

    A segmented core for an electric machine includes segments stamped from coated electric steel. The segments each have a first end, a second end, and winding openings. A predetermined number of segments are placed end-to-end to form layers. The layers are stacked such that each of the layers is staggered from adjacent layers by a predetermined rotation angle. The winding openings of each of the layers are in vertical alignment with the winding openings of the adjacent layers. The stack of layers is secured to form the segmented core.

  11. Electrical machines and assemblies including a yokeless stator with modular lamination stacks

    Science.gov (United States)

    Qu, Ronghai; Jansen, Patrick Lee; Bagepalli, Bharat Sampathkumar; Carl, Jr., Ralph James; Gadre, Aniruddha Dattatraya; Lopez, Fulton Jose

    2010-04-06

    An electrical machine includes a rotor with an inner rotor portion and an outer rotor portion, and a double-sided yokeless stator. The yokeless stator includes modular lamination stacks and is configured for radial magnetic flux flow. The double-sided yokeless stator is concentrically disposed between the inner rotor portion and the outer rotor portion of the electrical machine. Examples of particularly useful embodiments for the electrical machine include wind turbine generators, ship propulsion motors, switch reluctance machines and double-sided synchronous machines.

  12. Short-term wind power combined forecasting based on error forecast correction

    International Nuclear Information System (INIS)

    Liang, Zhengtang; Liang, Jun; Wang, Chengfu; Dong, Xiaoming; Miao, Xiaofeng

    2016-01-01

    Highlights: • The correlation relationships of short-term wind power forecast errors are studied. • The correlation analysis method of the multi-step forecast errors is proposed. • A strategy selecting the input variables for the error forecast models is proposed. • Several novel combined models based on error forecast correction are proposed. • The combined models have improved the short-term wind power forecasting accuracy. - Abstract: With the increasing contribution of wind power to electric power grids, accurate forecasting of short-term wind power has become particularly valuable for wind farm operators, utility operators and customers. The aim of this study is to investigate the interdependence structure of errors in short-term wind power forecasting that is crucial for building error forecast models with regression learning algorithms to correct predictions and improve final forecasting accuracy. In this paper, several novel short-term wind power combined forecasting models based on error forecast correction are proposed in the one-step ahead, continuous and discontinuous multi-step ahead forecasting modes. First, the correlation relationships of forecast errors of the autoregressive model, the persistence method and the support vector machine model in various forecasting modes have been investigated to determine whether the error forecast models can be established by regression learning algorithms. Second, according to the results of the correlation analysis, the range of input variables is defined and an efficient strategy for selecting the input variables for the error forecast models is proposed. Finally, several combined forecasting models are proposed, in which the error forecast models are based on support vector machine/extreme learning machine, and correct the short-term wind power forecast values. The data collected from a wind farm in Hebei Province, China, are selected as a case study to demonstrate the effectiveness of the proposed

  13. Towards mass-market development of wind energy

    International Nuclear Information System (INIS)

    Palz, W.

    1996-01-01

    The wind turbine technologies employed in today's markets for wind energy are innovative, efficient and in many cases cost competitive. A world market of more than 1000 MW/year and with a turnover of 1 billion ECU has developed and 30,000 new jobs have been created, most of them in small and medium size enterprises. 80% of today's world production is European. The preferred turbine capacity of today is 500 kW. In the next few years a three-fold increase in the rated power of most commercial machines to 1.5 MW is expected. The new large machines have been achieved through the ''WEGA''-programme of the European Commission. Significant market penetration of wind power in the European Union is very recent. The 2500 MW installed wind capacity in Europe today accounts only for 1/2% of the total capacity available for electricity production. Markets of the future will depend on a better development of the economic integration issues of wind energy into large networks. A key is the cost of electric grids which conditions the opportunity cost for feeding wind power at any particular point into the grids. Also, better predictability of the wind resource will give higher value to wind power in the grid and improve its economics further. Various financing schemes have been set up throughout Europe. Financial support and incentives are vital for some more years to come to expand current markets and improve economics through economy of scale. The utilisation of wind turbines in off-grid situations is an important new field for technological innovations and deployment. (author)

  14. Design of a 3 kW wind turbine generator with thin airfoil blades

    Energy Technology Data Exchange (ETDEWEB)

    Ameku, Kazumasa; Nagai, Baku M.; Roy, Jitendro Nath [Faculty of Mechanical Engineering, University of the Ryukyus, 1 Senbaru, Nishihara-cho, Okinawa 903-0213 (Japan)

    2008-09-15

    Three blades of a 3 kW prototype wind turbine generator were designed with thin airfoil and a tip speed ratio of 3. The wind turbine has been controlled via two control methods: the variable pitch angle and by regulation of the field current of the generator and examined under real wind conditions. The characteristics of the thin airfoil, called ''Seven arcs thin airfoil'' named so because the airfoil is composed of seven circular arcs, are analyzed with the airfoil design and analysis program XFOIL. The thin airfoil blade is designed and calculated by blade element and momentum theory. The performance characteristics of the machine such as rotational speed, generator output as well as stability for wind speed changes are described. In the case of average wind speeds of 10 m/s and a maximum of 19 m/s, the automatically controlled wind turbine ran safely through rough wind conditions and showed an average generator output of 1105 W and a power coefficient 0.14. (author)

  15. Dynamic Performance of the Standalone Wind Power Driven Heat Pump

    OpenAIRE

    H. Li; P.E. Campana; S. Berretta; Y. Tan; J. Yan

    2016-01-01

    Reducing energy consumption and increasing use of renewable energyin the building sector arecrucial to the mitigation of climate change. Wind power driven heat pumps have been considered as a sustainable measure to supply heat for detached houses, especially those that even don’t have access to the grid. This work is to investigate the dynamic performance of a heat pump system directly driven by a wind turbine. The heat demand of a detached single family house was simulated in details. Accord...

  16. A data-driven multi-model methodology with deep feature selection for short-term wind forecasting

    International Nuclear Information System (INIS)

    Feng, Cong; Cui, Mingjian; Hodge, Bri-Mathias; Zhang, Jie

    2017-01-01

    Highlights: • An ensemble model is developed to produce both deterministic and probabilistic wind forecasts. • A deep feature selection framework is developed to optimally determine the inputs to the forecasting methodology. • The developed ensemble methodology has improved the forecasting accuracy by up to 30%. - Abstract: With the growing wind penetration into the power system worldwide, improving wind power forecasting accuracy is becoming increasingly important to ensure continued economic and reliable power system operations. In this paper, a data-driven multi-model wind forecasting methodology is developed with a two-layer ensemble machine learning technique. The first layer is composed of multiple machine learning models that generate individual forecasts. A deep feature selection framework is developed to determine the most suitable inputs to the first layer machine learning models. Then, a blending algorithm is applied in the second layer to create an ensemble of the forecasts produced by first layer models and generate both deterministic and probabilistic forecasts. This two-layer model seeks to utilize the statistically different characteristics of each machine learning algorithm. A number of machine learning algorithms are selected and compared in both layers. This developed multi-model wind forecasting methodology is compared to several benchmarks. The effectiveness of the proposed methodology is evaluated to provide 1-hour-ahead wind speed forecasting at seven locations of the Surface Radiation network. Numerical results show that comparing to the single-algorithm models, the developed multi-model framework with deep feature selection procedure has improved the forecasting accuracy by up to 30%.

  17. Machine Learing Applications on a Radar Wind Profiler Deployment During the ARM GoAmazon2014/5 Campaign

    Science.gov (United States)

    Giangrande, S. E.; WANG, D.; Hardin, J. C.; Mitchell, J.

    2017-12-01

    As part of the 2 year Department of Energy Atmospheric Radiation Measurement (ARM) Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign, the ARM Mobile Facility (AMF) collected a unique set of observations in a region of strong climatic significance near Manacapuru, Brazil. An important example for the beneficial observational record obtained by ARM during this campaign was that of the Radar Wind Profiler (RWP). This dataset has been previously documented for providing critical convective cloud vertical air velocity retrievals and precipitation properties (e.g., calibrated reflectivity factor Z, rainfall rates) under a wide variety of atmospheric conditions. Vertical air motion estimates to within deep convective cores such as those available from this RWP system have been previously identified as critical constraints for ongoing global climate modeling activities and deep convective cloud process studies. As an extended deployment within this `green ocean' region, the RWP site and collocated AMF surface gauge instrumentation experienced a unique hybrid of tropical and continental precipitation conditions, including multiple wet and dry season precipitation regimes, convective and organized stratiform storm dynamics and contributions to rainfall accumulation, pristine aerosol conditions of the locale, as well as the effects of the Manaus, Brazil, mega city pollution plume. For hydrological applications and potential ARM products, machine learning methods developed using this dataset are explored to demonstrate advantages in geophysical retrievals when compared to traditional methods. Emphasis is on performance improvements when providing additional information on storm structure and regime or echo type classifications. Since deep convective cloud dynamic insights (core updraft/downdraft properties) are difficult to obtain directly by conventional radars that also observe radar reflectivity factor profiles similar to RWP systems, we also

  18. Comparison of different wind data interpolation methods for a region with complex terrain in Central Asia

    Science.gov (United States)

    Reinhardt, Katja; Samimi, Cyrus

    2018-01-01

    While climatological data of high spatial resolution are largely available in most developed countries, the network of climatological stations in many other regions of the world still constitutes large gaps. Especially for those regions, interpolation methods are important tools to fill these gaps and to improve the data base indispensible for climatological research. Over the last years, new hybrid methods of machine learning and geostatistics have been developed which provide innovative prospects in spatial predictive modelling. This study will focus on evaluating the performance of 12 different interpolation methods for the wind components \\overrightarrow{u} and \\overrightarrow{v} in a mountainous region of Central Asia. Thereby, a special focus will be on applying new hybrid methods on spatial interpolation of wind data. This study is the first evaluating and comparing the performance of several of these hybrid methods. The overall aim of this study is to determine whether an optimal interpolation method exists, which can equally be applied for all pressure levels, or whether different interpolation methods have to be used for the different pressure levels. Deterministic (inverse distance weighting) and geostatistical interpolation methods (ordinary kriging) were explored, which take into account only the initial values of \\overrightarrow{u} and \\overrightarrow{v} . In addition, more complex methods (generalized additive model, support vector machine and neural networks as single methods and as hybrid methods as well as regression-kriging) that consider additional variables were applied. The analysis of the error indices revealed that regression-kriging provided the most accurate interpolation results for both wind components and all pressure heights. At 200 and 500 hPa, regression-kriging is followed by the different kinds of neural networks and support vector machines and for 850 hPa it is followed by the different types of support vector machine and

  19. Test results for the Oasis 3C high performance water-pumping windmill

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, D.M. [DME Engineering, Midland, TX (United States)

    1997-12-31

    The WINDTech International, L.L.C. Oasis 3C, a 3 m diameter, high-performance water-pumping windmill, was tested at the DME Engineering Wind Test Site just south of Midland, Texas from August through December, 1996. This machine utilizes a 3:1 gearbox with rotating counterweights, similar to a conventional oilfield pumping unit, driven by a multibladed rotor. The rotating counterweight system balances most of the pumping loads and reduces gear loads and starting torque by a factor of at least two and often by a factor of four or more. The torque reduction substantially extends gear and bearing life, and reduces wind speeds required for starting by 30 to 50% or more. The O3C was tested pumping from a quiescent fluid depth of 12.2 m (40 ft) from a 28.3 m (93 ft)-deep well, with additional pumping depth simulated using a pressure regulator valve system. A 9.53 cm (3.75 in.) diameter Harbison-Fischer seal-less single-acting piston pump was used to eliminate pump seal friction as a variable, and standard O3C stroke lengths of 30.5 and 15.2 cm (12 and 6 inches) were used. The regulator spring was set to give a maximum stroke rate of 33 strokes per minute. The water pumped was returned to the well after flowing through a settling tank. The tests were performed in accordance with AWEA WECS testing standards. Instrumentation provided 16 channels of data to accurately measure machine performance, including starting wind speeds, flow rates, O3C azimuth, tail furl angle, wind direction tracking errors, RPM, sucker rod loads, and other variables. The most significant performance data is summarized herein. A mathematical model of machine performance was developed that fairly accurately predicts performance for each of three test conditions. The results verify that the O3C is capable of pumping water at wind speeds from 30% to more than 50% lower than comparable un-counterbalanced units.

  20. Generalized gain scheduling for deloaded wind turbine operation

    DEFF Research Database (Denmark)

    Venne, Philippe; Guillaud, X.; Teodorescu, Remus

    2010-01-01

    to regulate both power production and rotor speed under any wind speed conditions. In this paper, a novel controller for deloaded wind turbine operation is presented. This controller is made possible by a Cp table inversion procedure allowing generalized gain scheduling for linearization of the pitch response......The ability to produce less power than what is available from a wind source, a condition known as deloaded operation, is needed for a wind turbine to reproduce synchronous machine behavior in terms of inertial response and frequency droop regulation. Deloaded operation requires the ability...

  1. A Sensor-less Method for Online Thermal Monitoring of Switched Reluctance Machine

    DEFF Research Database (Denmark)

    Wang, Chao; Liu, Hui; Liu, Xiao

    2015-01-01

    Stator winding is one of the most vulnerable parts in Switched Reluctance Machine (SRM), especially under thermal stresses during frequently changing operation circumstances and susceptible heat dissipation conditions. Thus real-time online thermal monitoring of the stator winding is of great sig...

  2. The current wind energy programme in Italy

    International Nuclear Information System (INIS)

    Ambrosini, G.; Foli, U.; Sesto, E.; Vigotti, R.

    1991-01-01

    In Italy, the main activities in the field of wind energy are carried out by two state-owned organizations, ENEA (Italian National Agency for New Technologies, Energy and the Environment) and ENEL (Italian National Electricity Board), and two major wind turbine generator manufacturers, Alenia/WEST and Riva Calzoni, within the framework of a national programme which is supervized by the Ministry of Industry and Commerce. The work currently under way concerns both wind power plant siting and the development and testing of Italian-made wind turbine generators ranging from 5 to 1500 kW in power. In addition, programmes aimed at constructing wind-farms made up of medium-sized machines (200-400 kW) have recently been launched

  3. Influence of winding construction on starter-generator thermal processes

    Science.gov (United States)

    Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

    2018-01-01

    Dynamic processes in starter-generators features high winding are overcurrent. It can lead to insulation overheating and fault operation mode. For hybrid and electric vehicles, new high efficiency construction of induction machines windings is proposed. Stator thermal processes need be considered in the most difficult operation modes. The article describes construction features of new compact stator windings, electromagnetic and thermal models of processes in stator windings and explains the influence of innovative construction on thermal processes. Models are based on finite element method.

  4. Wind energy: A review of technical and market issues

    Energy Technology Data Exchange (ETDEWEB)

    Garrad, A.D. [Garrad Hassan & Partners Ltd., Bristol (United Kingdom)

    1996-12-31

    Opinions on the world market for wind power are presented in this paper. The paper is divided into three sections: the market, the technology, and general conclusions. The market section compares European and US wind energy growth and contributing factors and barriers to growth. A technology overview discusses wind turbine concepts, mass reduction, blade structural flexibility, and growth in machine size. Political decisions, economic aspects, public acceptance, and technology limitations are assessed for their influence on the growth of wind energy. 11 figs.

  5. Impact of Offshore Wind Power Integrated by VSC-HVDC on Power Angle Stability of Power Systems

    Science.gov (United States)

    Lu, Haiyang; Tang, Xisheng

    2017-05-01

    Offshore wind farm connected to grid by VSC-HVDC loses frequency support for power system, so adding frequency control in wind farm and VSC-HVDC system is an effective measure, but it will change wind farm VSC-HVDC’s transient stability on power system. Through theoretical analysis, concluding the relationship between equivalent mechanical power and electromagnetic power of two-machine system with the active power of wind farm VSC-HVDC, then analyzing the impact of wind farm VSC-HVDC with or without frequency control and different frequency control parameters on angle stability of synchronous machine by EEAC. The validity of theoretical analysis has been demonstrated through simulation in PSCAD/EMTDC.

  6. Research Based on the Acoustic Emission of Wind Power Tower Drum Dynamic Monitoring Technology

    Science.gov (United States)

    Zhang, Penglin; Sang, Yuan; Xu, Yaxing; Zhao, Zhiqiang

    Wind power tower drum is one of the key components of the wind power equipment. Whether the wind tower drum performs safety directly affects the efficiency, life, and performance of wind power equipment. Wind power tower drum in the process of manufacture, installation, and operation may lead to injury, and the wind load and gravity load and long-term factors such as poor working environment under the action of crack initiation or distortion, which eventually result in the instability or crack of the wind power tower drum and cause huge economic losses. Thus detecting the wind power tower drum crack damage and instability is especially important. In this chapter, acoustic emission is used to monitor the whole process of wind power tower drum material Q345E steel tensile test at first, and processing and analysis tensile failure signal of the material. And then based on the acoustic emission testing technology to the dynamic monitoring of wind power tower drum, the overall detection and evaluation of the existence of active defects in the whole structure, and the acoustic emission signals collected for processing and analysis, we could preliminarily master the wind tower drum mechanism of acoustic emission source. The acoustic emission is a kind of online, efficient, and economic method, which has very broad prospects for work. The editorial committee of nondestructive testing qualification and certification of personnel teaching material of science and technology industry of national defense, "Acoustic emission testing" (China Machine Press, 2005.1).

  7. Survey of variable speed operation of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Ola; Hylander, J.; Thorborg, K. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1996-12-01

    During the last five years the production and operation of variable-speed wind turbines have advanced from a few experimental machines to a serial production of at least 10 MW of installed capacity of variable speed machines per week. The rated power of serial wind turbines is today around 600 kW and for the prototypes up to 3000 kW. Variable speed operation of wind turbines can be obtained with several different types of electrical generating systems, such as synchronous generators with diode rectifiers and thyristor inverters or induction generators with IGBT-converters, for the wide speed range. For the narrow speed range the wound motor induction generator with a rotor cascade or a controlled rotor resistance is preferable. The development of permanent magnetic material and the reduction of costs of the power electronic components have opened a possibility of designing cost-effective wind turbines with a directly driven generator. Pitch control together with variable speed will make it possible to limit the power variation within a few percent, 2 to 5 %, of the rated power. 7 refs, 4 figs, 2 tabs

  8. Development of superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2013-01-01

    In this paper, the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational...... speeds, because high magnetic fields can be produced by coils with very little loss. Three different superconducting wind turbine generator topologies have been proposed by three different companies. One is based on low temperature superconductors; one is based on high temperature superconductors......; and one is a fully superconducting generator based on MgB2. It is concluded that there is large commercial interest in superconducting machines, with an increasing patenting activity. Such generators are, however, not without their challenges. The superconductors have to be cooled down to somewhere...

  9. Development of Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2012-01-01

    In this paper the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational...... speeds, because high magnetic fields can be produced by coils with very little loss. Three different superconducting wind turbine generator topologies have been proposed by three different companies. One is based on low temperature superconductors (LTS); one is based on high temperature superconductors...... (HTS); and one is a fully superconducting generator based on MgB2. It is concluded that there is large commercial interest in superconducting machines, with an increasing patenting activity. Such generators are however not without their challenges. The superconductors have to be cooled down...

  10. International cooperation on wind energy for rural areas in China

    International Nuclear Information System (INIS)

    Pengfei, Shi

    1991-01-01

    An overview of the recent wind energy activities in China is given. China has a long history in harnessing the wind; modern development started during the late seventies. The Chinese wind potential is mainly in the coastal regions (North East and South East) and in Inner Mongolia. The actual total installed wind power is estimated to be 15 MW. For low lift (within 2 meters), high volume applications, e.g. salt making in salt pans along the coast, of mechanical windmills coupled to screw pumps have been developed. In Inner Mongolia, small portable wind generators (50-200 MW) charging car batteries are supplying some 100,000 farmer and herdsman families with electricity for television and lighting. The average energy consumption is between 200 and 300 kWh per year and the corresponding kWh price 0.40 to 0.50 US$. Since 1988 the demand for small wind generators declined due to the lower wool prices on the world market, affecting the income of the herdsman, and due to the fact that the machines have to be marketed in remote, less accesible rural areas. Various demonstration projects have been set up, f.e. a decentralized energy system on Dachen Island, including a wind diesel hybrid system. On Kongdon Island a 60 kW wind turbine and a 60 kW diesel generator were installed. With several foreign wind turbine manufacturers cooperations have been set up for licensed production in China. Also wind farms have been installed. The largest Chinese prototype at the moment is a 32 meter diameter, 200 kW machine. Western organizations or manufacturers are involved in most of the cooperatives. For the next five years the focus is on development of a large 150 and 200 kW machine and a windmill coupled to a centrifugal pump for lifting heads between 2 and 5 meter. 1 fig., 3 refs

  11. Operational performance of the Avispa-IIE wind generator in microhybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Galarza, Raul; Mejia Neri, Fortino [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The purpose of this paper is to make a general analysis over the operational performance of the Avispa-IIE wind generator in an Solar-Eolic hybrid installation, at an eco-tourist resort. This work was performed through the monitor of the wind generator and the system itself throughout a year, for the acquisition taking the variables of interest and operational parameters that might allow to characterize and to evaluate the general behavior of the system. Herein are the principals characteristics of the wind generator; its performance curve, the basic configuration of the installation and the control philosophy; Likewise, some technical and human problems which arise during the operation of the system are included, the implementation of improvements in the wind generator and the general results acquired during the time of operation of the wind generator in the cited installations. [Espanol] El proposito de este articulo es el hacer un analisis general del comportamiento operacional del aerogenerador Avispa-IIE en una instalacion hibrida Solar-Eolica en un lugar de veraneo eco-turistico. Este trabajo ha sido llevado a cabo mediante el monitor del aerogenerador y el sistema mismo por espacio de un ano, para la adquisicion de las variables de interes y de los parametros operacionales que pudieran servir para caracterizar y evaluar el comportamiento general del sistema. Aqui se incluyen las caracteristicas principales del aerogenerador; su curva de comportamiento, la configuracion basica de la instalacion y la filosofia del control. De la misma manera se incluyen algunos problemas tecnicos y humanos que se originan durante la operacion del sistema y la puesta en practica de las mejoras del aerogenerador y los resultados generales adquiridos durante el tiempo de operacion del aerogenerador en las instalaciones citadas.

  12. Operational performance of the Avispa-IIE wind generator in microhybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Galarza, Raul; Mejia Neri, Fortino [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The purpose of this paper is to make a general analysis over the operational performance of the Avispa-IIE wind generator in an Solar-Eolic hybrid installation, at an eco-tourist resort. This work was performed through the monitor of the wind generator and the system itself throughout a year, for the acquisition taking the variables of interest and operational parameters that might allow to characterize and to evaluate the general behavior of the system. Herein are the principals characteristics of the wind generator; its performance curve, the basic configuration of the installation and the control philosophy; Likewise, some technical and human problems which arise during the operation of the system are included, the implementation of improvements in the wind generator and the general results acquired during the time of operation of the wind generator in the cited installations. [Espanol] El proposito de este articulo es el hacer un analisis general del comportamiento operacional del aerogenerador Avispa-IIE en una instalacion hibrida Solar-Eolica en un lugar de veraneo eco-turistico. Este trabajo ha sido llevado a cabo mediante el monitor del aerogenerador y el sistema mismo por espacio de un ano, para la adquisicion de las variables de interes y de los parametros operacionales que pudieran servir para caracterizar y evaluar el comportamiento general del sistema. Aqui se incluyen las caracteristicas principales del aerogenerador; su curva de comportamiento, la configuracion basica de la instalacion y la filosofia del control. De la misma manera se incluyen algunos problemas tecnicos y humanos que se originan durante la operacion del sistema y la puesta en practica de las mejoras del aerogenerador y los resultados generales adquiridos durante el tiempo de operacion del aerogenerador en las instalaciones citadas.

  13. IEA Wind Task 26. Wind Technology, Cost, and Performance Trends in Denmark, Germany, Ireland, Norway, the European Union, and the United States: 2007–2012

    Energy Technology Data Exchange (ETDEWEB)

    Vitina, Aisma [Ea Energy Analyses, Copenhagen (Denmark); Lüers, Silke [Deutsche WindGuard, Varel (Germany); Wallasch, Anna-Kathrin [Deutsche WindGuard, Varel (Germany); Berkhout, Volker [Fraunhofer IWES, Kassel (Germany); Duffy, Aidan [Dublin Inst. of Technology and Dublin Energy Lab. (Ireland); Cleary, Brendan [Dublin Inst. of Technology and Dublin Energy Lab. (Ireland); Husabø, Lief I. [Norwegian Water Resources and Energy Directorate (NVE), Oslo (Norway); Weir, David E. [Norwegian Water Resources and Energy Directorate (NVE), Oslo (Norway); Lacal-Arántegui, Roberto [European Commission, Ispra (Italy). Joint Research Centre; Hand, Maureen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lantz, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Belyeu, Kathy [Belyeu Consulting, Takoma Park, MD (United States); Wiser, Ryan H [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bolinger, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hoen, Ben [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-06-01

    The International Energy Agency Implementing Agreement for cooperation in Research, Development, and Deployment of Wind Energy Systems (IEA Wind) Task 26—The Cost of Wind Energy represents an international collaboration dedicated to exploring past, present and future cost of wind energy. This report provides an overview of recent trends in wind plant technology, cost, and performance in those countries that are currently represented by participating organizations in IEA Wind Task 26: Denmark, Germany, Ireland, Norway, and the United States as well as the European Union.

  14. Experimental verification of the effect of cable length on voltage distribution in stator winding of an induction motor under surge condition

    Energy Technology Data Exchange (ETDEWEB)

    Oyegoke, B.S. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Electromechanics

    1997-12-31

    This paper presents the results of surge distribution tests performed on a stator of a 6 kV induction motor. The primary aim of these tests was to determine the wave propagation properties of the machine winding fed via cables of different lengths. Considering the measured resorts, conclusions are derived regarding the effect of cable length on the surge distribution within the stator winding of an ac motor. (orig.) 15 refs.

  15. Influences of some parameters on the performance of a small vertical axis wind turbine

    Directory of Open Access Journals (Sweden)

    Dumitrache Alexandru

    2016-01-01

    Full Text Available The effects of various parameters on the performance of a straight bladed vertical axis wind turbine, using the vortex model, have been numerically investigated. A vortex model has been used to evaluate the performance of a vertical axis wind turbine, by means of aerodynamic characteristics of different airfoils for Reynolds numbers between 105 and 106. Parameters such as the thickness and the camber of the blade airfoil, the solidity, the type of blade profile, the number of blades and the pitch angle, which influence the power coefficient, CP, and the start-up regime. This study can be used in the designing an optimal vertical axis wind turbine in a specific location, when the prevailed wind regime is known.

  16. Technology, Performance, and Market Report of Wind-Diesel Applications for Remote and Island Communities: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.; Dabo, M.

    2009-02-01

    This paper describes the current status of wind-diesel technology and its applications, the current research activities, and the remaining system technical and commercial challenges. System architectures, dispatch strategies, and operating experience from a variety of wind-diesel systems will be discussed, as well as how recent development to explore distributed energy generation solutions for wind generation can benefit from the performance experience of operating systems. The paper also includes a detailed discussion of the performance of wind-diesel applications in Alaska, where 10 wind-diesel stations are operating and additional systems are currently being implemented. Additionally, because this application represents an international opportunity, a community of interest committed to sharing technical and operating developments is being formed. The authors hope to encourage this expansion while allowing communities and nations to investigate the wind-diesel option for reducing their dependence on diesel-driven energy sources.

  17. Technology, Performance, and Market Report of Wind-Diesel Applications for Remote and Island Communities: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.; Dabo, M.

    2009-05-01

    This paper describes the current status of wind-diesel technology and its applications, the current research activities, and the remaining system technical and commercial challenges. System architectures, dispatch strategies, and operating experience from a variety of wind-diesel systems will be discussed, as well as how recent development to explore distributed energy generation solutions for wind generation can benefit from the performance experience of operating systems. The paper also includes a detailed discussion of the performance of wind-diesel applications in Alaska, where 10 wind-diesel stations are operating and additional systems are currently being implemented. Additionally, because this application represents an international opportunity, a community of interest committed to sharing technical and operating developments is being formed. The authors hope to encourage this expansion while allowing communities and nations to investigate the wind-diesel option for reducing their dependence on diesel-driven energy sources.

  18. A kernel plus method for quantifying wind turbine performance upgrades

    KAUST Repository

    Lee, Giwhyun

    2014-04-21

    Power curves are commonly estimated using the binning method recommended by the International Electrotechnical Commission, which primarily incorporates wind speed information. When such power curves are used to quantify a turbine\\'s upgrade, the results may not be accurate because many other environmental factors in addition to wind speed, such as temperature, air pressure, turbulence intensity, wind shear and humidity, all potentially affect the turbine\\'s power output. Wind industry practitioners are aware of the need to filter out effects from environmental conditions. Toward that objective, we developed a kernel plus method that allows incorporation of multivariate environmental factors in a power curve model, thereby controlling the effects from environmental factors while comparing power outputs. We demonstrate that the kernel plus method can serve as a useful tool for quantifying a turbine\\'s upgrade because it is sensitive to small and moderate changes caused by certain turbine upgrades. Although we demonstrate the utility of the kernel plus method in this specific application, the resulting method is a general, multivariate model that can connect other physical factors, as long as their measurements are available, with a turbine\\'s power output, which may allow us to explore new physical properties associated with wind turbine performance. © 2014 John Wiley & Sons, Ltd.

  19. Wind data for wind driven plant. [site selection for optimal performance

    Science.gov (United States)

    Stodhart, A. H.

    1973-01-01

    Simple, averaged wind velocity data provide information on energy availability, facilitate generator site selection and enable appropriate operating ranges to be established for windpowered plants. They also provide a basis for the prediction of extreme wind speeds.

  20. Prediction of windings temperature rise in induction motors supplied with distorted voltage

    Energy Technology Data Exchange (ETDEWEB)

    Gnacinski, P. [Gdynia Maritime University, Department of Ship Electrical Power Engineering, Morska Street 83, 81-225 Gdynia (Poland)

    2008-04-15

    One of the features of ship power systems is a different level and intensity of disturbances appearing during routine operation - the rms voltage value and frequency deviation, voltage unbalance and waveform voltage distortion. As a result, marine induction machines are exposed to overheating due to the lowered voltage quality. This paper is devoted to windings temperature rise prediction in marine induction cage machines supplied with distorted voltage, which means real voltage conditions. The proposed method of prediction does not require detailed knowledge of the thermal properties of a machine. Although the method was developed for marine induction motors, it is applicable for industry machines supplied with distorted voltage. It can also be generalized and used for estimation of the steady state windings temperature rise of any electrical machinery in various work conditions. (author)

  1. Prediction of windings temperature rise in induction motors supplied with distorted voltage

    International Nuclear Information System (INIS)

    Gnacinski, P.

    2008-01-01

    One of the features of ship power systems is a different level and intensity of disturbances appearing during routine operation - the rms voltage value and frequency deviation, voltage unbalance and waveform voltage distortion. As a result, marine induction machines are exposed to overheating due to the lowered voltage quality. This paper is devoted to windings temperature rise prediction in marine induction cage machines supplied with distorted voltage, which means real voltage conditions. The proposed method of prediction does not require detailed knowledge of the thermal properties of a machine. Although the method was developed for marine induction motors, it is applicable for industry machines supplied with distorted voltage. It can also be generalized and used for estimation of the steady state windings temperature rise of any electrical machinery in various work conditions

  2. PV-wind hybrid system performance. A new approach and a case study

    International Nuclear Information System (INIS)

    Arribas, Luis; Cano, Luis; Cruz, Ignacio; Mata, Montserrat; Llobet, Ermen

    2010-01-01

    Until now, there is no internationally accepted guideline for the measurement, data exchange and analysis of PV-Wind Hybrid Systems. As there is a need for such a tool, so as to overcome the barrier that the lack of confidence due to the absence of reliability means for the development of the market of Hybrid Systems, an effort has been made to suggest one tool for PV-Wind Hybrid Systems. The suggested guidelines presented in this work are based on the existing guidelines for PV Systems, as a PV-Wind Hybrid system can be roughly thought of as a PV System to which wind generation has been added. So, the guidelines for PV Systems are valid for the PV-Wind System, and only the part referred to wind generation should be included. This has been the process followed in this work. The proposed method is applied to a case study, the CICLOPS Project, a 5 kW PV, 7.5 kW Wind Hybrid system installed at the Isolated Wind Systems Test Site that CIEMAT owns in CEDER (Soria, Spain). This system has been fully monitored through a year and the results of the monitoring activity, characterizing the long-term performance of the system are shown in this work. (author)

  3. PV-wind hybrid system performance. A new approach and a case study

    Energy Technology Data Exchange (ETDEWEB)

    Arribas, Luis; Cano, Luis; Cruz, Ignacio [Departamento de Energias Renovables, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain); Mata, Montserrat; Llobet, Ermen [Ecotecnia, Roc Boronat 78, 08005 Barcelona (Spain)

    2010-01-15

    Until now, there is no internationally accepted guideline for the measurement, data exchange and analysis of PV-Wind Hybrid Systems. As there is a need for such a tool, so as to overcome the barrier that the lack of confidence due to the absence of reliability means for the development of the market of Hybrid Systems, an effort has been made to suggest one tool for PV-Wind Hybrid Systems. The suggested guidelines presented in this work are based on the existing guidelines for PV Systems, as a PV-Wind Hybrid system can be roughly thought of as a PV System to which wind generation has been added. So, the guidelines for PV Systems are valid for the PV-Wind System, and only the part referred to wind generation should be included. This has been the process followed in this work. The proposed method is applied to a case study, the CICLOPS Project, a 5 kW PV, 7.5 kW Wind Hybrid system installed at the Isolated Wind Systems Test Site that CIEMAT owns in CEDER (Soria, Spain). This system has been fully monitored through a year and the results of the monitoring activity, characterizing the long-term performance of the system are shown in this work. (author)

  4. Wind Energy Department: Scientific and technical progress 1999-2000

    DEFF Research Database (Denmark)

    2001-01-01

    The activities of the Wind Energy Department fall within boundary layer meteorology, atmospheric turbulence, aerodynamics, aero-acoustics, structural dynamics, machine and construction technology and design of power systems and power system controls. Theobjective is to develop methods for design......; test and siting of wind turbines; prediction of wind loads and wind resources as well as methods to determine the dispersion, transformation and effect of air pollution. The present report describes theorganisation of the department and presents selected scientific highlights and results from the two...

  5. Effect of changing polarity of graphite tool/ Hadfield steel workpiece couple on machining performances in die sinking EDM

    Directory of Open Access Journals (Sweden)

    Özerkan Haci Bekir

    2017-01-01

    Full Text Available In this study, machining performance ouput parameters such as machined surface roughness (SR, material removal rate (MRR, tool wear rate (TWR, were experimentally examined and analyzed with the diversifying and changing machining parameters in (EDM. The processing parameters (input par. of this research are stated as tool material, peak current (I, pulse duration (ton and pulse interval (toff. The experimental machinings were put into practice by using Hadfield steel workpiece (prismatic and cylindrical graphite electrodes with kerosene dielectric at different machining current, polarity and pulse time settings. The experiments have shown that the type of tool material, polarity (direct polarity forms higher MRR, SR and TWR, current (high current lowers TWR and enhances MRR, TWR and pulse on time (ton=48□s is critical threshold value for MRR and TWR were influential on machining performance in electrical discharge machining.

  6. Performance Evaluation of Machine Learning Algorithms for Urban Pattern Recognition from Multi-spectral Satellite Images

    Directory of Open Access Journals (Sweden)

    Marc Wieland

    2014-03-01

    Full Text Available In this study, a classification and performance evaluation framework for the recognition of urban patterns in medium (Landsat ETM, TM and MSS and very high resolution (WorldView-2, Quickbird, Ikonos multi-spectral satellite images is presented. The study aims at exploring the potential of machine learning algorithms in the context of an object-based image analysis and to thoroughly test the algorithm’s performance under varying conditions to optimize their usage for urban pattern recognition tasks. Four classification algorithms, Normal Bayes, K Nearest Neighbors, Random Trees and Support Vector Machines, which represent different concepts in machine learning (probabilistic, nearest neighbor, tree-based, function-based, have been selected and implemented on a free and open-source basis. Particular focus is given to assess the generalization ability of machine learning algorithms and the transferability of trained learning machines between different image types and image scenes. Moreover, the influence of the number and choice of training data, the influence of the size and composition of the feature vector and the effect of image segmentation on the classification accuracy is evaluated.

  7. Unsteady Flow in Different Atmospheric Boundary Layer Regimes and Its Impact on Wind-Turbine Performance

    Science.gov (United States)

    Gohari, Iman; Korobenko, Artem; Yan, Jinhui; Bazilevs, Yuri; Sarkar, Sutanu

    2016-11-01

    Wind is a renewable energy resource that offers several advantages including low pollutant emission and inexpensive construction. Wind turbines operate in conditions dictated by the Atmospheric Boundary Layer (ABL) and that motivates the study of coupling ABL simulations with wind turbine dynamics. The ABL simulations can be used for realistic modeling of the environment which, with the use of fluid-structure interaction, can give realistic predictions of extracted power, rotor loading, and blade structural response. The ABL simulations provide inflow boundary conditions to the wind-turbine simulator which uses arbitrary Lagrangian-Eulerian variational multiscale formulation. In the present work, ABL simulations are performed to examine two different scenarios: (i) A neutral ABL with zero heat-flux and inversion layer at 350m, in which the wind turbine experiences maximum mean shear; (2) A shallow ABL with the surface cooling-rate of -1 K/hr, in which the wind turbine experiences maximum mean velocity at the low-level-jet nose height. We will discuss differences in the unsteady flow between the two different ABL conditions and their impact on the performance of the wind turbine cluster in the coupled ABL-wind turbine simulations.

  8. Flow widening through a Darrieus wind turbine - Theory and experiment

    Science.gov (United States)

    Comolet, R.; Harajli, I.; Mercier Des Rochettes, P.; Yeznasni, A.

    1982-11-01

    A two-dimensional multiple stream tube model is developed for the air flow through a Darrieus wind turbine. The model is configured to account for the widening of the flux tubes as they cross the interior of the actuator disk. Note is made of the lateral broadening of the flow as it moves through the area, leaving a turbulent wake. A relation is defined between the variation in the kinetic energy of the flow and the aerodynamic forces acting on the blades. The global efficiency and the power output of the machine are calculated. Experimental results are reported for a machine equipped with two NACA 0015 blades, each 110 cm long and with a 10 cm chord. The Darrieus had a 1 m diam and was tested in a wind tunnel at wind speeds of 0-18 m/sec. Soap bubbles inflated with He were used for visualization. Power output was found to match prediction. The model is recommended for use in calculating the forces acting on the machine and studying vibration and fatigue causative mechanisms.

  9. Comparison of Machine Learning Techniques in Inferring Phytoplankton Size Classes

    Directory of Open Access Journals (Sweden)

    Shuibo Hu

    2018-03-01

    Full Text Available The size of phytoplankton not only influences its physiology, metabolic rates and marine food web, but also serves as an indicator of phytoplankton functional roles in ecological and biogeochemical processes. Therefore, some algorithms have been developed to infer the synoptic distribution of phytoplankton cell size, denoted as phytoplankton size classes (PSCs, in surface ocean waters, by the means of remotely sensed variables. This study, using the NASA bio-Optical Marine Algorithm Data set (NOMAD high performance liquid chromatography (HPLC database, and satellite match-ups, aimed to compare the effectiveness of modeling techniques, including partial least square (PLS, artificial neural networks (ANN, support vector machine (SVM and random forests (RF, and feature selection techniques, including genetic algorithm (GA, successive projection algorithm (SPA and recursive feature elimination based on support vector machine (SVM-RFE, for inferring PSCs from remote sensing data. Results showed that: (1 SVM-RFE worked better in selecting sensitive features; (2 RF performed better than PLS, ANN and SVM in calibrating PSCs retrieval models; (3 machine learning techniques produced better performance than the chlorophyll-a based three-component method; (4 sea surface temperature, wind stress, and spectral curvature derived from the remote sensing reflectance at 490, 510, and 555 nm were among the most sensitive features to PSCs; and (5 the combination of SVM-RFE feature selection techniques and random forests regression was recommended for inferring PSCs. This study demonstrated the effectiveness of machine learning techniques in selecting sensitive features and calibrating models for PSCs estimations with remote sensing.

  10. Control system of power supply for resistance welding machine

    Directory of Open Access Journals (Sweden)

    Світлана Костянтинівна Поднебенна

    2017-06-01

    Full Text Available This article describes the existing methods of heat energy stabilizing, which are realized in thyristor power supplies for resistance welding machines. The advantages and features of thyristor power supplies have been described. A control system of power supply for resistance welding machine with stabilization of heat energy in a welding spot has been developed. Measurements are performed in primary winding of a welding transformer. Weld spot heating energy is calculated as the difference between the energy, consumed from the mains, and the energy losses in the primary and secondary circuits of the welding transformer as well as the energy losses in the transformer core. Algorithms of digital signal processing of the developed control system are described in the article. All measurements and calculations are preformed automatically in real-time. Input signals to the control system are: transformer primary voltage and current, temperature of the welding circuit. The designed control system ensures control of the welding heat energy and is not influenced by the supply voltage and impedance changes caused by insertion of the ferromagnetic mass in the welding circuit, the temperature change during the welding process. The developed control system for resistance welding machine makes it possible to improve the quality of welded joints, increase the efficiency of the resistance welding machine

  11. Advanced Control Strategy of Back-to-Back PWM Converters in PMSG Wind Power System

    Directory of Open Access Journals (Sweden)

    Tan Luong Van

    2015-01-01

    Full Text Available This paper proposes a control scheme of back-to-back PWM converters for the permanent magnet synchronous generator (PMSG wind turbine system. The DC-link voltage can be controlled at the machine-side converter (MSC, while the grid-side converter (GSC controls the grid active power for a maximum power point tracking (MPPT. At the grid fault condition, the DC-link voltage controller is designed using a feedback linearization (FL theory. For the MPPT, a proportional control loop is added to the torque control to reduce the influence of the inertia moment in the wind turbines, which can improve its dynamic performance. The validity of this control algorithm has been verified by the simulation of the 2-MW PMSG wind turbine system.

  12. Composite wind turbine towers

    Energy Technology Data Exchange (ETDEWEB)

    Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2008-07-01

    This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

  13. Torque ripple reduction in electric machines

    Science.gov (United States)

    Reddy, Patel Bhageerath; Huh, Kum-Kang; El-Refaie, Ayman Mohamed Fawzi; Galioto, Steven Joseph

    2017-08-22

    An electric machine, such as an Internal Permanent magnet or Synchronous Reluctance machine, having X phases, that includes a stator assembly, having M slots, with a stator core and stator teeth, that is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface that defines a cavity; and a rotor assembly, having N poles, disposed within the cavity which is configured to rotate about the longitudinal axis, wherein the rotor assembly includes a shaft, a rotor core located circumferentially around the shaft. The machine is configured such that a value k=M/(X*N) wherein k is a non-integer greater than about 1.3. The electric machine may alternatively, or additionally, include a non-uniformed gap between the exterior surface of the rotor spokes and the interior stator surface of the stator.

  14. Field weakening performance of flux-switching machines for hybrid/electric vehicles

    NARCIS (Netherlands)

    Tang, Y.; Paulides, J.J.H.; Lomonova, E.A.

    2015-01-01

    Flux-switching machines (FSMs) are a viable candidate for electric propulsion of hybrid/electric vehicles. This paper investigates the field weakening performance of FSMs. The investigation starts with general torque and voltage expressions, which reveal the relationships between certain parameters

  15. A real-scale helical coil winding trial of the Large Helical Device

    International Nuclear Information System (INIS)

    Senba, T.; Yamamoto, T.; Tamaki, T.; Asano, K.; Suzuki, S.; Yamauchi, T.; Uchida, K.; Nakanishi, K.; Yamagiwa, T.; Suzuki, S.; Miyoshi, R.; Sasa, H.; Watanabe, S.; Tatemura, M.; Hatada, N.; Yamaguchi, S.; Imagawa, S.; Yanagi, N.; Satow, T.; Yamamoto, J.; Motojima, O.

    1995-01-01

    A real-scale helical coil winding trial of the Large Helical Device (LHD) has been conducted for a study of coil winding configuration and winding methods and for exhibiting the state of the art. It includes construction and test run of a specifically designed winding machine and development of various manufacturing methods for accurate coil winding. It has been carried out in Hitachi Works before in situ winding, and has provided much needed engineering data for construction of the LHD. (orig.)

  16. Evaluation of small wind turbines in distributed arrangement as sustainable wind energy option for Barbados

    International Nuclear Information System (INIS)

    Bishop, Justin D.K.; Amaratunga, Gehan A.J.

    2008-01-01

    The island of Barbados is 99% dependent on fossil fuel imports to satisfy its energy needs, which is unsustainable. This study proposes a 10 MW distributed wind energy scheme using micro wind turbines (WT) of horizontal (HAWT) and vertical axis (VAWT) configurations. These units are rated less than 500 W, and the scheme is hereafter referred to as mWT10. mWT10 is compared to the proposed 10 MW medium WT farm by the Barbados Light and Power Company (BL and P). The economic bottom line is the levelized cost of electricity (LCOE). The results highlight the BL and P proposal as the best economic option at BDS$0.19 per kWh, while that of both mWT10 configurations exceeds the conventional cost of BDS$0.25 by two to nine times. This is attributed to significantly higher relative installation and operational costs. However, the financial gap between mWT10 LCOE and the retail price of electricity is much smaller due to a large fuel surcharge passed on to each customer. Annual additional benefits of using wind energy include: greenhouse gas emissions savings of 6-23 kt of carbon dioxide; and anavoided fuel costs of BDS$1.5-5.3 million. The distributed mWT10 using HAWTs competes directly with the BL and P farm, however, it provides these benefits without the visual or ecological impacts of the larger machines. Conversely, VAWTs have features that favour a visually discrete and widely repeatable scheme but suffer relatively high costs. Therefore, this study illustrates the great potential of small wind turbines to be competitive with conventional wind farms, thus challenging the small wind industry to meet its potential by producing reliable and robust machines at lower cost

  17. Gearless wind power generator

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, L.; Ridanpaeae, P.; Vihriaelae, H.; Peraelae, R. [Tampere Univ. of Technology (Finland). Lab. of Electricity and Magnetism

    1998-12-31

    During the wind power generator project a design algorithm for a gearless permanent magnet generator with an axially orientated magnetic flux was developed and a 10 kW model machine was constructed. Utilising the test results a variable wind speed system of 100 kW was designed that incorporates a permanent magnet generator, a frequency converter and a fuzzy controller. This system produces about 5-15% more energy than existing types and stresses to the blades are minimised. The type of generator designed in the project represents in general a gearless solution for slow-speed electrical drives. (orig.)

  18. Wind energy department: Scientific and technical progress 1999 - 2000

    International Nuclear Information System (INIS)

    Skrumsager, B.; Larsen, G.

    2001-01-01

    The activities of the Wind Energy Department fall within boundary layer meteorology, atmospheric turbulence, aerodynamics, aero-acoustics, structural dynamics, machine and construction technology and design of power systems and power system controls. The objective is to develop methods for design; test and siting of wind turbines; prediction of wind loads and wind resources as well as methods to determine the dispersion, transformation and effect of air pollution. The present report describes the organisation of the department and presents selected scientific highlights and results from the two-year period 1999-2000. (au)

  19. Wind energy utilization: A bibliography with abstracts - Cumulative volume 1944/1974

    Science.gov (United States)

    1975-01-01

    Bibliography, up to 1974 inclusive, of articles and books on utilization of wind power in energy generation. Worldwide literature is surveyed, and short abstracts are provided in many cases. The citations are grouped by subject: (1) general; (2) utilization; (3) wind power plants; (4) wind power generators (rural, synchronous, remote station); (5) wind machines (motors, pumps, turbines, windmills, home-built); (6) wind data and properties; (7) energy storage; and (8) related topics (control and regulation devices, wind measuring devices, blade design and rotors, wind tunnel simulation, aerodynamics). Gross-referencing is aided by indexes of authors, corporate sources, titles, and keywords.

  20. Impact of wind velocity on the performance of the RVACS decay heat removal system

    International Nuclear Information System (INIS)

    Tzanos, C.P.

    1997-01-01

    The impact of wind velocity on the performance of the reactor vessel auxiliary cooling system (RVACS) of an advanced liquid-metal reactor design is analyzed, and design modifications that mitigate adverse wind effects are investigated. In the reference design, the reactor is served by four communicating RVACS stacks, and each stack has two air inlets. In this two-inlet stack design, winds blowing in a direction 90 deg from the axis formed by the two stack inlets result in pressure distributions around the stacks that drastically change the desired airflow pattern in the RVACS. This leads to significantly elevated RVACS air temperatures and significant azimuthal guard vessel temperature variations. For example, a 27 m/s (60 mph) wind leads to an air temperature at the exit of the RVACS heated section that is ∼115 C higher than that under no-wind conditions. The addition of two more inlets per stack, one inlet per stack side, significantly improves RVACS performance. The air temperature at the exit of the heated RVACS section is significantly reduced below that of the two-inlet design, and this temperature decreases as the wind speed increases. An increase in wind speed from 3 to 27 m/s leads to an air temperature change from 186 to 165 C. The azimuthal temperature variation is also improved. At the top of the guard vessel, this variation is reduced from 62.5 to 8.5 C at the low wind speed of 3 m/s and from 85.0 to 30.5 C at the high wind speed of 27 m/s

  1. Wind power plant for electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Landsiedel, E

    1978-11-09

    The invention concerns a wind power plant which rotates on a vertical axis and is suitable for the generation of electricity. This wind power machine with a vertical axis can be mounted at any height, so that it can catch the wind on the vertical axis of rotation. Further, it does not have to be turned into the direction of the wind and fixed. The purpose of the invention is to obtain equal load on the structure due to the vertical axis. The purpose of the invention is fulfilled by having the wind vanes fixed above one another from the bottom to the top in 6 different directions. The particular advantage of the invention lies in the fact that the auxiliary blades can bring the other blades to the operating position in good time, due to their particular method of fixing.

  2. Modification and Performance Evaluation of a Low Cost Electro-Mechanically Operated Creep Testing Machine

    Directory of Open Access Journals (Sweden)

    John J. MOMOH

    2010-12-01

    Full Text Available Existing mechanically operated tensile and creep testing machine was modified to a low cost, electro-mechanically operated creep testing machine capable of determining the creep properties of aluminum, lead and thermoplastic materials as a function of applied stress, time and temperature. The modification of the testing machine was necessitated by having an electro-mechanically operated creep testing machine as a demonstration model ideal for use and laboratory demonstrations, which will provide an economical means of performing standard creep experiments. The experimental result is a more comprehensive understanding of the laboratory experience, as the technology behind the creep testing machine, the test methodology and the response of materials loaded during experiment are explored. The machine provides a low cost solution for Mechanics of Materials laboratories interested in creep testing experiment and demonstration but not capable of funding the acquisition of commercially available creep testing machines. Creep curves of strain versus time on a thermoplastic material were plotted at a stress level of 1.95MPa, 3.25MPa and 4.55MPa and temperature of 20oC, 40oC and 60oC respectively. The machine is satisfactory since it is always ready for operation at any given time.

  3. Comparison of stator-mounted permanent-magnet machines based on a general power equation

    DEFF Research Database (Denmark)

    Chen, Zhe; Hua, Wei; Cheng, Ming

    2009-01-01

    The stator-mounted permanent-magnet (SMPM) machines have some advantages compared with its counterparts, such as simple rotor, short winding terminals, and good thermal dissipation conditions for magnets. In this paper, a general power equation for three types of SMPM machine is introduced first...

  4. Wind Generation Participation in Power System Frequency Response: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, Vahan; Zhang, Yingchen

    2017-01-01

    The electrical frequency of an interconnected power system must be maintained close its nominal level at all times. Excessive under- and overfrequency excursions can lead to load shedding, instability, machine damage, and even blackouts. There is a rising concern in the electric power industry in recent years about the declining amount of inertia and primary frequency response (PFR) in many interconnections. This decline may continue due to increasing penetrations of inverter-coupled generation and the planned retirements of conventional thermal plants. Inverter-coupled variable wind generation is capable of contributing to PFR and inertia with a response that is different from that of conventional generation. It is not yet entirely understood how such a response will affect the system at different wind power penetration levels. The modeling work presented in this paper evaluates the impact of wind generation's provision of these active power control strategies on a large, synchronous interconnection. All simulations were conducted on the U.S. Western Interconnection with different levels of instantaneous wind power penetrations (up to 80%). The ability of wind power plants to provide PFR - and a combination of synthetic inertial response and PFR - significantly improved the frequency response performance of the system.

  5. Using Random Forests to Select Optimal Input Variables for Short-Term Wind Speed Forecasting Models

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2017-10-01

    Full Text Available Achieving relatively high-accuracy short-term wind speed forecasting estimates is a precondition for the construction and grid-connected operation of wind power forecasting systems for wind farms. Currently, most research is focused on the structure of forecasting models and does not consider the selection of input variables, which can have significant impacts on forecasting performance. This paper presents an input variable selection method for wind speed forecasting models. The candidate input variables for various leading periods are selected and random forests (RF is employed to evaluate the importance of all variable as features. The feature subset with the best evaluation performance is selected as the optimal feature set. Then, kernel-based extreme learning machine is constructed to evaluate the performance of input variables selection based on RF. The results of the case study show that by removing the uncorrelated and redundant features, RF effectively extracts the most strongly correlated set of features from the candidate input variables. By finding the optimal feature combination to represent the original information, RF simplifies the structure of the wind speed forecasting model, shortens the training time required, and substantially improves the model’s accuracy and generalization ability, demonstrating that the input variables selected by RF are effective.

  6. The typhoon effect on the aerodynamic performance of a floating offshore wind turbine

    Directory of Open Access Journals (Sweden)

    Zhe Ma

    2017-12-01

    Full Text Available The wind energy resource is considerably rich in the deep water of China South Sea, where wind farms have to face the challenge of extreme typhoon events. In this work, the typhoon effect on the aerodynamic performance of the 5MW OC3-Hywind floating offshore wind turbine (FOWT system has been investigated, based on the Aero-Hydro-Servo-Elastic FAST code. First, considering the full field observation data of typhoon “Damrey” is a long duration process with significant turbulence and high wind speed, so one 3-h representative truncated typhoon wind speed time history has been selected. Second, the effects of both the (variable-speed and collective-pitch control system of NREL 5 MW wind turbine and the motion of the floating platform on the blade aerodynamic performance of the FOWT system during the representative typhoon time history has been investigated, based on blade element momentum (BEM theory (coupled with potential theory for the calculation of the hydrodynamic loads of the Spar platform. Finally, the effects of different wind turbine control strategies, control parameter (KP–KI combinations, wave heights and parked modes on the rotor aerodynamic responses of the FOWT system have been clarified. The extreme typhoon event can result in considerably large extreme responses of the rotor thrust and the generated power due to the possible blade pitch angle error phenomenon. One active-parked strategy has been proposed for reducing the maximum aerodynamic responses of the FOWT system during extreme typhoon events.

  7. Smoothing Control of Wind Farm Output by Using Kinetic Energy of Variable Speed Wind Power Generators

    Science.gov (United States)

    Sato, Daiki; Saitoh, Hiroumi

    This paper proposes a new control method for reducing fluctuation of power system frequency through smoothing active power output of wind farm. The proposal is based on the modulation of rotaional kinetic energy of variable speed wind power generators through power converters between permanent magnet synchronous generators (PMSG) and transmission lines. In this paper, the proposed control is called Fluctuation Absorption by Flywheel Characteristics control (FAFC). The FAFC can be easily implemented by adding wind farm output signal to Maximum Power Point Tracking control signal through a feedback control loop. In order to verify the effectiveness of the FAFC control, a simulation study was carried out. In the study, it was assumed that the wind farm consisting of PMSG type wind power generator and induction machine type wind power generaotors is connected with a power sysem. The results of the study show that the FAFC control is a useful method for reducing the impacts of wind farm output fluctuation on system frequency without additional devices such as secondary battery.

  8. Performance Evaluation of Eleven-Phase Induction Machine with Different PWM Techniques

    Directory of Open Access Journals (Sweden)

    M.I. Masoud

    2015-06-01

    Full Text Available Multiphase induction machines are used extensively in low and medium voltage (MV drives. In MV drives, power switches have a limitation associated with switching frequency. This paper is a comparative study of the eleven-phase induction machine’s performance when used as a prototype and fed sinusoidal pulse-width-modulation (SPWM with a low switching frequency, selective harmonic elimination (SHE, and single pulse modulation (SPM techniques. The comparison depends on voltage/frequency controls for the same phase of voltage applied on the machine terminals for all previous techniques. The comparative study covers torque ripple, stator and harmonic currents, and motor efficiency.

  9. Direct Interval Forecasting of Wind Power

    DEFF Research Database (Denmark)

    Wan, Can; Xu, Zhao; Pinson, Pierre

    2013-01-01

    This letter proposes a novel approach to directly formulate the prediction intervals of wind power generation based on extreme learning machine and particle swarm optimization, where prediction intervals are generated through direct optimization of both the coverage probability and sharpness...

  10. The Effect of Upscaling and Performance Degradation on Onshore Wind Turbine Lifetime Extension Decision Making

    Science.gov (United States)

    Rubert, T.; McMillan, D.; Niewczas, P.

    2017-11-01

    Ever greater rated wind turbine generators (WTGs) are reaching their end of design life in the near future. In addition, first research approaches quantified the impact of long-term performance degradation of WTGs. As a consequence, this work is aimed at discussing and analysing the impact of upscaling and performance degradation on the economics of wind turbine lifetime extension. Findings reveal that the lifetime extension levelised cost of energy (LCOE2) of an 18 MW wind farm comprising of 0.5 MW rated WTGs are within the order of £23.52 per MWh. Alternatively, if the same wind farm consists of fewer 2 or 3 MW WTGs, the LCOE2 reduces to £16.56 or £15.49 per MWh, respectively. Further, findings reveal that an annual performance degradation of 1.6% (0.2%) increases LCOE2 by 34-41% (3.6-4.3%).

  11. Sensorless speed detection of squirrel-cage induction machines using stator neutral point voltage harmonics

    Science.gov (United States)

    Petrovic, Goran; Kilic, Tomislav; Terzic, Bozo

    2009-04-01

    In this paper a sensorless speed detection method of induction squirrel-cage machines is presented. This method is based on frequency determination of the stator neutral point voltage primary slot harmonic, which is dependent on rotor speed. In order to prove method in steady state and dynamic conditions the simulation and experimental study was carried out. For theoretical investigation the mathematical model of squirrel cage induction machines, which takes into consideration actual geometry and windings layout, is used. Speed-related harmonics that arise from rotor slotting are analyzed using digital signal processing and DFT algorithm with Hanning window. The performance of the method is demonstrated over a wide range of load conditions.

  12. Technology assessment of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B. W.; Merson, T. J.

    1980-09-01

    Environmental data for wind energy conversion systems (WECSs) have been generated in support of the Technology Assessment of Solar Energy (TASE) program. Two candidates have been chosen to characterize the WECS that might be deployed if this technology makes a significant contribution to the national energy requirements. One WECS is a large machine of 1.5-MW-rated capacity that can be used by utilities. The other WECS is a small machine that is characteristic of units that might be used to meet residential or small business energy requirements. Energy storage systems are discussed for each machine to address the intermittent nature of wind power. Many types of WECSs are being studied and a brief review of the technology is included to give background for choosing horizontal axis designs for this study. Cost estimates have been made for both large and small systems as required for input to the Strategic Environmental Assessment Simulation (SEAS) computer program. Material requirements, based on current generation WECSs, are discussed and a general discussion of environmental impacts associated with WECS deployment is presented.

  13. Unsteady Aerodynamics of a Savonius wind rotor: a new computational approach for the simulation of energy performance

    Energy Technology Data Exchange (ETDEWEB)

    D' Alessandro, V.; Montelpare, S.; Ricci, R.; Secchiaroli, A. [Universita Politecnica delle Marche, Dipartimento di Energetica, Via Brecce Bianche 1, 60131 Ancona (Italy)

    2010-08-15

    When compared with of other wind turbine the Savonius wind rotor offers lower performance in terms of power coefficient, on the other hand it offers a number of advantages as it is extremely simple to built, it is self-starting and it has no need to be oriented in the wind direction. Although it is well suited to be integrated in urban environment as mini or micro wind turbine it is inappropriate when high power is requested. For this reason several studies have been carried-out in recent years in order to improve its aerodynamic performance. The aim of this research is to gain an insight into the complex flow field developing around a Savonius wind rotor and to evaluate its performance. A mathematical model of the interaction between the flow field and the rotor blades was developed and validated by comparing its results with data obtained at Environmental Wind Tunnel (EWT) laboratory of the ''Polytechnic University of Marche''. (author)

  14. Predictive Power of Machine Learning for Optimizing Solar Water Heater Performance: The Potential Application of High-Throughput Screening

    Directory of Open Access Journals (Sweden)

    Hao Li

    2017-01-01

    Full Text Available Predicting the performance of solar water heater (SWH is challenging due to the complexity of the system. Fortunately, knowledge-based machine learning can provide a fast and precise prediction method for SWH performance. With the predictive power of machine learning models, we can further solve a more challenging question: how to cost-effectively design a high-performance SWH? Here, we summarize our recent studies and propose a general framework of SWH design using a machine learning-based high-throughput screening (HTS method. Design of water-in-glass evacuated tube solar water heater (WGET-SWH is selected as a case study to show the potential application of machine learning-based HTS to the design and optimization of solar energy systems.

  15. Investigations of Cutting Fluid Performance Using Different Machining Operations

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Belluco, Walter

    2002-01-01

    An analysis of cutting fluid performance in dif-ferent metal cutting operations is presented based on performance criteria, work material and fluid type. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping operations, with respect to tool life, cutting forces and prod...... will get the same performance ranking for different metalworking fluids no matter what machining test is used, when the fluids are of the same type. Results show that this is mostly true for the water-based fluids on austenitic stainless steel while ranking did change depending on the test with straight......-gated. In the case of austenitic stainless steel as the workpiece material, results using the different operations under different cutting conditions show that the performance of vegetable oil based prod-ucts is superior or equal to that of mineral oil based products. The hypothesis was investigated that one...

  16. Implementation of Total Productive Maintenance (TPM to Improve Sheeter Machine Performance

    Directory of Open Access Journals (Sweden)

    Candra Nofri Eka

    2017-01-01

    Full Text Available This paper purpose is an evaluation of TPM implementation, as a case study at sheeter machine cut size line 5 finishing department, PT RAPP, Indonesia. Research methodology collected the Overall Equipment Effectiveness (OEE data of sheeter machine and computed its scores. Then, OEE analysis big losses, statistical analysis using SPSS 20 and focused maintenance evaluation of TPM were performed. The data collected to machine sheeter’s production for 10 months (January-October 2016. The data analyses was resulted the OEE average score of 82.75%. This score was still below the world class OEE (85% and the company target (90%. Based the big losses of OEE analysis was obtained the reduce speed losses, which most significant losses of OEE scores. The reduce speed losses value was 44.79% of total losses during the research period. The high score of these losses due to decreasing of machine production speed by operators, which intended to improve the quality of resulting products. The OEE scores statistical analysis was found breakdown losses and reduces speed losses, which significantly affected to OEE scores. Implementations of focused maintenance of TPM in the case study may need to improve because there were still occurred un-expecting losses during the research period.

  17. Wire electric-discharge machining and other fabrication techniques

    Science.gov (United States)

    Morgan, W. H.

    1983-01-01

    Wire electric discharge machining and extrude honing were used to fabricate a two dimensional wing for cryogenic wind tunnel testing. Electric-discharge cutting is done with a moving wire electrode. The cut track is controlled by means of a punched-tape program and the cutting feed is regulated according to the progress of the work. Electric-discharge machining involves no contact with the work piece, and no mechanical force is exerted. Extrude hone is a process for honing finish-machined surfaces by the extrusion of an abrasive material (silly putty), which is forced through a restrictive fixture. The fabrication steps are described and production times are given.

  18. Decentralized/stand-alone hybrid Wind-Diesel power systems to meet residential loads of hot coastal regions

    International Nuclear Information System (INIS)

    Elhadidy, M.A.; Shaahid, S.M.

    2005-01-01

    In view of rising costs, pollution and fears of exhaustion of oil and coal, governments around the world are encouraging to seek energy from renewable/sustainable energy sources such as wind. The utilization of energy from wind (since the oil embargo of the 1970s) is being widely disseminated for displacement of fossil fuel produced energy and to reduce atmospheric degradation. A system that consists of a wind turbine and Diesel genset is called a Wind-Diesel power system.The literature indicates that the commercial/residential buildings in Saudi Arabia consume an estimated 10-40% of the total electric energy generated. In the present study, the hourly mean wind-speed data of the period 1986-1997 recorded at the solar radiation and meteorological station, Dhahran (26 deg. 32'N, 50 deg. 13'E in the Eastern Coastal Region of Saudi Arabia), has been analyzed to investigate the potential of utilizing hybrid (Wind-Diesel) energy conversion systems to meet the load requirements of a hundred typical two bedroom residential buildings (with annual electrical energy demand of 3512 MWh). The long term monthly average wind speeds for Dhahran range from 4.2 to 6.4 m/s. The hybrid systems considered in the present case study consist of different combinations/clusters of 150 kW commercial wind machines supplemented with battery storage and Diesel back-up. The deficit energy generated by the Diesel generator (for different battery capacities) and the number of operational hours of the Diesel system to meet a specific annual electrical energy demand of 3512 MWh have also been presented. The evaluation of the hybrid system shows that with seven 150 kW wind energy conversion system (WECS) and one day of battery storage, the Diesel back-up system has to provide 21.6% of the load demand. Furthermore, with three days of battery storage, the Diesel back-up system has to provide 17.5% of the load demand. However, in the absence of battery storage, about 37% of the load needs to be

  19. Objective estimation of tropical cyclone innercore surface wind structure using infrared satellite images

    Science.gov (United States)

    Zhang, Changjiang; Dai, Lijie; Ma, Leiming; Qian, Jinfang; Yang, Bo

    2017-10-01

    An objective technique is presented for estimating tropical cyclone (TC) innercore two-dimensional (2-D) surface wind field structure using infrared satellite imagery and machine learning. For a TC with eye, the eye contour is first segmented by a geodesic active contour model, based on which the eye circumference is obtained as the TC eye size. A mathematical model is then established between the eye size and the radius of maximum wind obtained from the past official TC report to derive the 2-D surface wind field within the TC eye. Meanwhile, the composite information about the latitude of TC center, surface maximum wind speed, TC age, and critical wind radii of 34- and 50-kt winds can be combined to build another mathematical model for deriving the innercore wind structure. After that, least squares support vector machine (LSSVM), radial basis function neural network (RBFNN), and linear regression are introduced, respectively, in the two mathematical models, which are then tested with sensitivity experiments on real TC cases. Verification shows that the innercore 2-D surface wind field structure estimated by LSSVM is better than that of RBFNN and linear regression.

  20. Wind farms providing secondary frequency regulation: evaluating the performance of model-based receding horizon control

    Directory of Open Access Journals (Sweden)

    C. R. Shapiro

    2018-01-01

    Full Text Available This paper is an extended version of our paper presented at the 2016 TORQUE conference (Shapiro et al., 2016. We investigate the use of wind farms to provide secondary frequency regulation for a power grid using a model-based receding horizon control framework. In order to enable real-time implementation, the control actions are computed based on a time-varying one-dimensional wake model. This model describes wake advection and wake interactions, both of which play an important role in wind farm power production. In order to test the control strategy, it is implemented in a large-eddy simulation (LES model of an 84-turbine wind farm using the actuator disk turbine representation. Rotor-averaged velocity measurements at each turbine are used to provide feedback for error correction. The importance of including the dynamics of wake advection in the underlying wake model is tested by comparing the performance of this dynamic-model control approach to a comparable static-model control approach that relies on a modified Jensen model. We compare the performance of both control approaches using two types of regulation signals, RegA and RegD, which are used by PJM, an independent system operator in the eastern United States. The poor performance of the static-model control relative to the dynamic-model control demonstrates that modeling the dynamics of wake advection is key to providing the proposed type of model-based coordinated control of large wind farms. We further explore the performance of the dynamic-model control via composite performance scores used by PJM to qualify plants for regulation services or markets. Our results demonstrate that the dynamic-model-controlled wind farm consistently performs well, passing the qualification threshold for all fast-acting RegD signals. For the RegA signal, which changes over slower timescales, the dynamic-model control leads to average performance that surpasses the qualification threshold, but further