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Number of results: 12
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Abstract

This work analyzes the process of construction and manufacturing of a blade used in a wind turbine. The calculation scheme is presented for forces generated on the blade of a wind turbine and parameters are determined of weather conditions in which the designed element would be working. Subsequently, for the chosen aerodynamic profile the characteristics are calculated of its aerodynamic coefficients, which enables the establishing of the angle of attack which impacts the yield of wind engines. The presented process is an introduction to 3D modelling of a wind turbine’s blade and simulation of its creation in a CAM environment.
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Authors and Affiliations

Karol Tucki
Mateusz Zimoch
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Abstract

On power generation and the future of Polish offshore wind farms.
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Authors and Affiliations

Paweł Flaszyński
1
Karol Mitraszewski
2
Joanna Markowska Cerić
2

  1. PAS Institute of Fluid-Flow Machinery, Gdańsk, Poland
  2. PGE Baltica sp. z o.o., Warsaw, Poland
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Abstract

By means of small wind turbines, it is possible to create distributed sources of electricity useful in areas with good wind conditions. Sometimes, however, it is possible to use small wind turbines also in areas characterized by lower average wind speeds during the year. At the small wind turbine design stage, various types of technical solutions to increase the speed of the wind stream, as well as to optimally orientate it, can be applied. The methods for increasing the efficiency of wind energy conversion into electricity in the case of a wind turbine include: the use of a diffuser shielding the turbine rotor and the optimization of blades mounted on the turbine rotor. In the paper, the influence of the diffuser and rotor blades geometry on the efficiency of an exemplary wind turbine for exploitation in the West Pomeranian Province is investigated. The analyses are performed for three types of the diffuser and for three types of rotor blades. Based on them, the most optimal shapes of the diffuser and blades are selected due to the efficiency of the wind turbine. For the turbine with the designed diffuser, calculations of the output power for the assumed different values of the average annual wind speed and the constant Betz power factor and the specified generator efficiency are made. In all the analyzed cases, the amount of energy that can be generated by the turbine during the year is also estimated. Important practical conclusions are formulated on the basis of these calculations. In the final part of the paper, a 3D model of the wind turbine with the diffuser and rotor blades chosen based on earlier analyses is presented. As a material for the diffuser and rotor blades, glass fiber type A is applied. By means of calculations using the finite element method, the limit displacement of the turbine structure under the influence of a hurricane wind are determined. Based on these calculations, the correctness of the modelled small wind turbine structure has been demonstrated.

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Authors and Affiliations

Kamil Krzysztof Skorupa
Rafał Grzejda
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Abstract

The specific working conditions of the wind turbine in strong wind cause a number of problems in the measurement of noise indicators used in its short and long-term assessment. The wind is a natural working environment of the turbine, but it also affects the measurement system, moreover, it can be a secondary source of other sounds that interfere with the measurement. One of the effective methods of eliminating the direct impact of wind on the measurement system is placing the microphone on the measurement board at ground level. However, the obtained result can not be directly compared with the admissible values, as it has to be converted to a result at a height of 4 m. The results of previous studies show that this relation depends, inter alia, on the speed and direction of the wind. The paper contains the results of measurements on the measurement board, according to EN 61400-11:2013, and at a height of 4 m above ground made simultaneously in three points around the 2 MW turbine at various instantaneous speeds and changing wind directions. Analysis of the impact of measuring point location on the measurement result of noise indicators and the occurrence of additional features affecting the relationship between the values measured on the board and at the height of 4 m, and especially the tonality, amplitude modulation and content of low frequency content, was m

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Authors and Affiliations

Tadeusz Wszołek
Paweł Pawlik
Dominik Mleczko
Jagna Chronowska
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Abstract

The degradation process of wind turbines is greatly affected by external factors. Wind turbine maintenance costs are high. The regular maintenance of wind turbines can easily lead to over and insufficient maintenance. To solve the above problems, a stochastic degradation model (SDE, stochastic differential equation) is proposed to simulate the change of the state of the wind turbine. First, the average degradation trend is obtained by analyzing the properties of the stochastic degradation model. Then the average degradation model is used to describe the predictive degradation model. Then analyze the change trend between the actual degradation state and the predicted state of the wind turbine. Secondly, according to the update process theory, the effect of maintenance on the state of wind turbines is comprehensively analyzed to obtain the availability. Then based on the average degradation process, the optimal maintenance period of the wind turbine is obtained. The optimal maintenance time of wind turbines is obtained by optimizing the maintenance cycle through availability constraints. Finally, an onshore wind turbine is used as an example to verification. Based on the historical fault data of wind turbines, the optimized maintenance decision is obtained by analyzing the reliability and maintenance cost of wind turbines under periodic and non-equal cycle conditions. The research results show that maintenance based on this model can effectively improve the performance of wind turbines and reduce maintenance costs.
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Bibliography

[1] Tchakoua P., Wamkeue R., Ouhrouche M. et al., Wind turbine condition monitoring: state-of-the-art review, new trends, and future challenges, Energies, vol. 7, no. 4, pp. 2595–2630 (2014).
[2] Su C., Hu Z.Y., Reliability assessment for Chinese domestic wind turbines based on data mining techniques, Wind Energy, vol. 21, no. 3, pp. 198–209 (2018).
[3] Zhao Hongshan, Zhang Jianping, Gao Duo et al., A condition based opportunistic maintenance strategy for wind turbine, Proceedings of the CSEE, vol. 35, no. 15, pp. 3851–3858 (2015).
[4] ChengYujing, Optimization maintenance research of wind turbines pitch system based on opportunistic maintenance strategy, Shanghai, Shang Hai Dianji University (2013).
[5] Li Hui, Yang Chao, Li Xuewei et al., Conditions characteristic parameters mining and outlier identification for electric pitch system of wind turbine, Proceedings of the CSEE, vol. 34, no. 12, pp. 1922–1930 (2014).
[6] Besnard F., Bertling L., An approach for condition-based maintenance optimization applied to wind turbine blades, IEEE Transactions on Sustainable Energy, vol. 1, no. 2, pp. 77–83 (2010).
[7] Liu Lujie, FuYang,Ma Shiwei et al., Maintenance strategy for offshore wind turbine based on condition monitoring and prediction, Power System Technology, vol. 39, no. 11, pp. 3292–3297 (2015).
[8] Suprasad V., Amari Leland Mclaughlin, Hoang Pham, Cost-effective condition-based maintenance using Markov decision processes, Reliability and Maintainability Symposium, pp. 464–469 (2006).
[9] Zhao Hongshan, Zhang Jianping, Gao Duo et al., A condition based opportunistic maintenance strategy for wind turbine under imperfect maintenance, Proceedings of the CSEE, vol. 36, no. 3, pp. 3851–3858 (2016).
[10] Li Dazi, Feng Yuanyuan, Liu Zhan et al., Reliability modeling and maintenance strategy optimization for wind power generation sets, Power System Technology, vol. 35, no. 9, pp. 122–127 (2011).
[11] Fu Yang, Xu Weixin, Liu Lujie et al., Optimization of preventive opportunistic maintenance strategy for offshore wind turbine considering weather conditions, Proceedings of the CSEE, vol. 38, no. 20, pp. 5947–5956 (2018).
[12] Tian Z., Jin T., Wu B. et al., Condition based maintenance optimization for wind power generation systems under continuous monitoring, Renewable Energy, vol. 36, no. 5, pp. 1502–1509 (2011).
[13] Yildirim M., Gebraeel N., Sun X., Integrated Predictive Analytics and Optimization for Opportunistic Maintenance and Operations in Wind Farms, IEEE Transactions on Power Systems, pp. 4319–4328 (2017).
[14] Elwany A.H., Gebraeel N.Z., Sensor-driven prognostic models for equipment replacement and spare parts inventory, IIE Transactions, vol. 40, no. 7, pp. 629–639 (2008).
[15] Liu Haiqing, Lin Weijian, Li Yuancheng, Ultra-short-term wind power prediction based on copula function and bivariate EMD decomposition algorithm, Archives of Electrical Engineering, vol. 69, no. 2, pp. 271–286 (2020).
[16] Wang Shaohua, Zhang Yaohui et al., Optimal condition-based maintenance decision-making method of multi-component system based on simulation, Acta Armamentarii, vol. 38, no. 3, pp. 568–575 (2017).
[17] Liu Junqiang, Xie Jianwei et al., Residual lifetime prediction for aeroengines based on wiener process with random effect, Acta Aeronautica et Astronautica Sinica, vol. 36, no. 2, pp. 564–574 (2015).
[18] Palmer T.N., A nonlinear dynamical perspective on model error; A proposal for non-local stochasticdynamic parametrization in weather and climate prediction models, Quarterly Journal of the Royal Meteorological Society, vol. 127, no. 572, pp. 279–304 (2010).
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[20] Rausand M., System Reliability Theory: Models, Statistical Methods, and Applications, 2nd Edition, Statistical methods in reliability theory and practice, E. Horwood (2004).
[21] Su Hongsheng, Control strategy on preventive maintenance of repairable device, Journal of Zhejiang University (Engineering Science), vol. 44, no. 7, pp. 1308–1314 (2010).

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Authors and Affiliations

Hongsheng Su
1
Xuping Duan
1
ORCID: ORCID
Dantong Wang
1

  1. Lanzhou Jiaotong University, China
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Abstract

Minimum Entropy Deconvolution (MED) has been recently introduced to the machine condition monitoring field to enhance fault detection in rolling element bearings and gears. MED proved to be an excellent aid to the extraction of these impulses and diagnosing their origin, i.e. the defective component of the bearing. In this paper, MED is revisited and re-introduced with further insights into its application to fault detection and diagnosis in rolling element bearings. The MED parameter selection as well as its combination with pre-whitening is discussed. Two main cases are presented to illustrate the benefits of the MED technique. The first one was taken from a fan bladed test rig. The second case was taken from a wind turbine with an inner race fault. The usage of the MED technique has shown a strong enhancement for both fault detection and diagnosis. The paper contributes to the knowledge of fault detection of rolling element bearings through providing an insight into the usage of MED in rolling element bearings diagnostic. This provides a guide for the user to select optimum parameters for the MED filter and illustrates these on new interesting cases both from a lab environment and an actual case.

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Authors and Affiliations

Tomasz Barszcz
Nader Sawalhi
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Abstract

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.

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Authors and Affiliations

Piotr Gajewski
Krzysztof Pieńkowski
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Abstract

Wind turbines are nowadays one of the most promising energy sources. Every year, the amount of energy produced from the wind grows steadily. Investors demand turbine manufacturers to produce bigger, more efficient and robust units. These requirements resulted in fast development of condition-monitoring methods. However, significant sizes and varying operational conditions can make diagnostics of the wind turbines very challenging.

The paper shows the case study of a wind turbine that had suffered a serious rolling element bearing (REB) fault. The authors compare several methods for early detection of symptoms of the failure. The paper compares standard methods based on spectral analysis and a number of novel methods based on narrowband envelope analysis, kurtosis and cyclostationarity approach.

The very important problem of proper configuration of the methods is addressed as well. It is well known that every method requires setting of several parameters. In the industrial practice, configuration should be as standard and simple as possible. The paper discusses configuration parameters of investigated methods and their sensitivity to configuration uncertainties

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Authors and Affiliations

Jacek Urbanek
Tomasz Barszcz
Tadeusz Uhl
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Abstract

The main purpose of this article is to verify and validate the mathematical description of the airflow around a wind turbine with vertical axis of rotation, which could be considered as representative for this type of devices. Mathematical modeling of the airflow around wind turbines in particular those with the vertical axis is a problematic matter due to the complex nature of this highly swirled flow. Moreover, it is turbulent flow accompanied by a rotation of the rotor and the dynamic boundary layer separation. In such conditions, the key aspects of the mathematical model are accurate turbulence description, definition of circular motion as well as accompanying effects like centrifugal force or the Coriolis force and parameters of spatial and temporal discretization. The paper presents the impact of the different simulation parameters on the obtained results of the wind turbine simulation. Analysed models have been validated against experimental data published in the literature.
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Authors and Affiliations

Andrzej J. Nowak
Tomasz Krysiński
Zbigniew Buliński
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Abstract

The aim of the research was to determine the occurrence of possible, significant levels of infrasound and low frequency noise both in classrooms and around the primary school. Two sources of noise during research were significant: traffic on the national road and a wind farm, located near the school building. So far, few studies have been published regarding the impact of low-frequency, environmental noise from communication routes. The identification of hazards in a form of estimated noise levels resulted in preliminary information whether the location of the school near the road with significant traffic and the nearby wind farm can cause nuisance to children. There have been determined the criteria for assessing infrasound and low frequency noise. There have been made third octave band analyses of noise spectrum and the essential noise indicators were calculated. The results of learning in that school were thoroughly analysed for a long period of time and they were compared to the results obtained in other schools within a radius of 200 km situated near similar noise sources. Chosen assessment criteria show small exposure to low frequency noise. Measured infrasound noise levels are below hearing threshold.

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Authors and Affiliations

Adam Zagubień
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Abstract

The paper presents the current state of knowledge concerning the sources of noise generated by wind turbines, force measurement methodology, and assessment of noise onerousness in this type of installation, on the basis of a study concerning a wind farm with five REpower MM92 wind turbines and the electric power of 2 MW and the sound power level of 104.2 dB(A) each. Particular attention was focused on the often discussed problem of presence of infrasound generated by turbines and on the requirements of the applicable reference methodologies for the measurement of wind speed to 5 m/s, while the turbine reaches its full power at speeds above 10 m/s.
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Authors and Affiliations

Maciej Kłaczyński
Tadeusz Wszołek
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Abstract

In renewable systems, there may be conditions that can be either network error or power transmission line and environmental conditions such as when the wind speed is unbalanced and the wind turbine is connected to the grid. In this case, the control system is not damaged and will remain stable in the power transmission system. Voltage stability studies on an independent wind turbine at fault time and after fixing the error is one of the topics that can strengthen the future of independent collections. At the time of the fault, the network current increases dramatically, resulting in a higher voltage drop. Hence the talk of fast voltage recovery during error and after fixing the error and protection of rotor and grid side converters against the fault current and also protection against rising DC voltage (which sharply increases during error) is highly regarded. So, several improvements have been made to the construction of a doubly-fed induction generator (DFIG) turbine such as:

a) error detection system,

b) DC link protection,

c) crow bar circuit,

d) block of the rotor and stator side converters,

e) injecting reactive power during error,

f) nonlinear control design for turbine blades,

g) tuning and harmonization of controllers used to keep up the power quality and to stabilize the system output voltage in the power grid.

First, the dynamic models of a wind turbine, gearbox, and DFIG are presented. Then the controllers are modeled. The results of the simulation have been validated in MATLAB/Simulink.

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Authors and Affiliations

Ehsan Ganji
Mehdi Mahdavian
Hosein Shirzadi

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