Commercial Wind Turbine Research Articles

Wind energy potential assessment in the Persian Gulf: A spatial and temporal analysis

Despite the high capacity of wind energy in the offshore regions of Iran seas, wind power plants in these parts have not been significantly considered. In this study, the temporal and spatial wind characteristics and wind energy potential of the Persian Gulf are investigated during the years 2000–2017 based on the European Center for Medium-Range Weather Forecasts (ECMWF) ERA5 reanalysis data set. The spatio-temporal distributions of the annual, seasonal, monthly, and diurnal mean wind characteristics are presented using the 18-year hourly resolution results. Statistical analysis and variability indices of the wind parameters are presented. The Weibull density function is used to assess and analyze the wind characteristics of the region. The Weibull shape k and scale c parameters are calculated using the maximum likelihood estimation (MLE) method. Finally, the wind capacities at the 12 potential locations near the populated or industrial regions around the studied area are derived. Besides, the capacity factor and the potential energy output of two commercial wind turbines are investigated, which are appropriate for the locations at 50 m and 80 m hub heights. The present results can be used to develop of wind energy plans and wind energy potential assessment in the studied area.

Indirect Vector-Controlled Brushless Doubly-Fed Twin-Stator Induction Generator for Wind Energy Conversion Application

Wind energy conversion systems (WECSs) seem certain to play a major part in the world’s energy future due to their known high power capacity. The maximum power tracking is unavoidable due to the wind velocity variation and the non-linear relation with the turbine mechanical power. Commercial wind turbines are commonly coupled to either doubly-fed induction generators (DFIGs), wound rotor synchronous generators (WRSG) or permanent magnet synchronous generators (PMSGs). The DFIG-based WECS has several advantages over others. One of which is the power converter in such systems only deals with rotor power, hence the converter rating can run at reduced power rating. However, DFIG has the famous disadvantage of the presence of slip rings which leads to increased maintenance costs and outage times. Hence, brushless doublyfed induction machines (BDFIMs) can be considered as a viable alternative at the penalty of complicated controller requirement and limited decoupling control capability due to the machine’s non-linearity. In this paper, an enhanced performance indirect vector controller is proposed for WECS based on brushless doubly-fed twin-stator induction generator (BDFTSIG). The presented controller offers (i) simplified implementation, (ii) decoupled active-reactive power control, and (iii) a wide range of operation. The proposed controller performance is investigated under various loading conditions showing enhanced transient and minimal steady-state oscillations in addition to complete active/reactive power decoupling. The rigorous simulation and experimental results verify the claimed controller effectiveness under all possible operating conditions for sub- and super-synchronous speed range.

Combined Floating Offshore Wind and Solar PV

To mitigate the effects of wind variability on power output, hybrid systems that combine offshore wind with other renewables are a promising option. In this work we explore the potential of combining offshore wind and solar power through a case study in Asturias (Spain)—a region where floating solutions are the only option for marine renewables due to the lack of shallow water areas, which renders bottom-fixed wind turbines inviable. Offshore wind and solar power resources and production are assessed based on high-resolution data and the technical specifications of commercial wind turbines and solar photovoltaic (PV) panels. Relative to a typical offshore wind farm, a combined offshore wind–solar farm is found to increase the capacity and the energy production per unit surface area by factors of ten and seven, respectively. In this manner, the utilization of the marine space is optimized. Moreover, the power output is significantly smoother. To quantify this benefit, a novel Power Smoothing (PS) index is introduced in this work. The PS index achieved by combining floating offshore wind and solar PV is found to be of up to 63%. Beyond the interest of hybrid systems in the case study, the advantages of combining floating wind and solar PV are extensible to other regions where marine renewable energies are being considered.

Data-driven Performance Fault Detection in Commercial Wind Turbines

The operation and maintenance costs of wind parks make up a major fraction of a park's overall lifetime costs. They also include opportunity costs of lost revenue from avoidable power generation underperformance. We present a machine-learning based decision support method that minimizes these opportunity costs. By analyzing the stream of telemetry sensor data from the turbine operation, estimating highly accurate power reference relations and benchmarking, we can detect performance-related operational faults in a turbine- and site-specific manner. The most accurate power reference model is selected based on combinations of machine learning algorithms and regressor sets. Operating personnel can be alerted if a normal operating state boundary is exceeded. We demonstrate the performance fault detection method in a case study for a commercial grid-connected onshore wind turbine. Diagnosing a detected underperformance event, we find that the observed power generation deficiencies coincide with rotor blade misalignment related to low hydraulic pressure of the turbine's blade actuators.

Wind energy resource assessment of Kütahya, Turkey using WAsP and layout optimization

Kütahya is considered as a candidate region for a wind farm investment due to Turkey's 2023 energy targets and its proximity to other wind farm investments. In this study, two years of wind data collected from a hill near the Evliya Çelebi Campus of Kütahya Dumlupınar University was used to evaluate the wind farm potential of Kütahya. First, the wind speed, wind direction, wind shear, turbulence intensity and wind speed ramp characteristics were determined. Second, the WAsP software was used to create a wind atlas for the region. Three sites with strong wind potential were evaluated. A techno-economic analysis was conducted using five types of wind turbines selected from the WAsP database. Third, optimization of a wind farm layout was conducted by considering different hub height options for 14 commercial wind turbines using MATLAB software. It was shown theoretically that a wind farm with a power capacity of 25 MW can operate with a capacity factor of 35%. However, due to the relatively high topographical ruggedness index on the wind farm site, the calculated value for the capacity factor could not be reached in a real-life application.

Field monitoring of the ground vibrations adjacent to an onshore wind turbine foundation

Investigations of the soil–foundation interaction behaviour of wind turbine foundations and transfer of energy from the wind to the ground have not been reported in Canada. Indeed, very few vibration monitoring studies have been conducted globally around wind farms. It has been found that turbines predominantly produce vibrations related to structural resonances and blade-passing frequencies. Energy is found to be modified with distance and is dominated by surface waves. This paper describes a study of the effect of wind–structure interaction on the behaviour of a turbine foundation and the generation of ground-based vibrations around a working commercial wind turbine in Ontario. The field monitoring system and meteorological instrumentation are described in this paper and the responses of the structure and surrounding ground due to the fluctuating wind-field are discussed. The spectral analysis shows that the higher frequency vibrations attenuate more rapidly than the lower frequency vibrations. The tilted elliptical particle motions are found to be non-Gaussian because of the non-Gaussian wind conditions. The response attenuation with distance indicates that both geometric and material attenuation may dominate the vibration attenuation in the near field and only geometric attenuation occurs in the far field.

Robust control design for an industrial wind turbine with HIL simulations

This paper describes the design and implementation of a H∞-based robust controller for a commercial 2MW variable-speed variable-pitch wind turbine. The single controller is able to deliver specification performance for the entire full load region. Various aspects of modeling and design procedures including reduced order model validation, torsional mode damping of drivetrain and uncertainty estimation are explained in detail. To make the design more reliable and industrially attractive, simple routines for the derivation of required weighting functions are introduced. To investigate the benefits of the suggested design, its closed-loop performance is compared with the wind turbine’s baseline controller and an alternative state–space controller proposed in the literature. This is first evaluated using a FAST-based simulator under IEC-61400 compatible scenarios. It is then verified by a real-life hardware in the loop simulator using an industrial PLC.

Wind and solar energy utilization for seawater desalination and hydrogen production in the coastal areas of southern Iran

PurposeAcute shortage of potable water and energy supplies is expected to raise in developing countries in the near future. One solid way to address these issues is to exploit renewable energy resources efficiently. Hence, this study aims to investigate wind and solar energy use in the coastal areas of southern Iran for renewable-powered seawater desalination and hydrogen production systems.Design/methodology/approachTo accomplish the aforementioned purpose, five areas most prone to the problems in Iran, namely, Mahshahr, Jask and Chabahar ports and Kish and Hormoz islands were scrutinized. To ascertain the amount of wind and solar energy available in the areas, Weibull distribution function, Angstrom–Prescott equation and HOMER software were used.FindingsThe findings indicated that wind energy density in Kish was 2,014.86 (kWh/m2.yr) and solar energy density in Jask equaled to 2,255.7 (kWh/m2.yr) which possessed the best conditions among the areas under study. Moreover, three commercial wind turbines and three photovoltaic systems were examined for supplying energy needed by the water desalination and hydrogen production systems. The results showed that application of wind turbines with rated power of 660, 750 and 900 kWh in Kish could result in desalting 934,145, 1,263,339 and 2,000,450 (m3/yr) of seawater or producing 14,719, 20,896 and 31,521 (kg/yr) of hydrogen, respectively. Additionally, use of photovoltaic systems with efficiency of %14.4, %17.01 and %21.16 in Jask could desalinate 287, 444 and 464 (m3/yr) of seawater or generate 4.5, 7 and 7.3 (kg/yr) of hydrogen, respectively.Originality/valueCompared to the huge extent of water shortage and environmental pollution, there has not been conducted enough studies to obtain broader view regarding use of renewable energies to solve these issues in Iran. Therefore, this study tries to close this gap and to give other developing nations the idea of water desalination and hydrogen production via renewable energies.

Análisis técnico y financiero del potencial energético del viento para generar energía eléctrica: el caso de Apan, Hidalgo

Objetivo: Evaluar el potencial energético del viento en Apan, Hidalgo. Metodología: Se emplean dos tipos de análisis: el análisis técnico y el análisis financiero. Para el estudio técnico se emplea la función de densidad de probabilidad Weibull. Así mismo, para el análisis financiero se evalúan los siguientes parámetros: valor presente neto, la tasa interna de rendimiento, el Costo Nivelado de la Electricidad, el período de recuperación y la razón costo/beneficio. Resultados: Se encontró que de los doce aerogeneradores considerados solo ocho son técnicamente viables y ninguno económicamente. Recomendaciones: Se recomienda no hacer la instalación de aerogeneradores comerciales. Limitaciones e implicaciones: La limitación de la función de densidad de probabilidad de Weibull es que no representa correctamente las probabilidades de la velocidad del viento cuando esta es muy baja o cercana a cero. Orignalidad: De acuerdo a la revisión de la literatura este estudio es la primera investigación para el caso de Apan, Hidalgo que analiza el potencial energético del viento y su factibilidad financiera. Conclusiones: La evidencia sugiere que el potencial del viento es adecuado para aplicaciones que no están conectadas a la red eléctrica e insuficiente para la producción de energía a escala comercial.

Investigation of the Flow Over NACA 63-415 Airfoil

In this article, a two-dimensional, incompressible flow around a NACA 63-415 airfoil, which is widely used as one of the commercial wind turbine blade profiles, is investigated. The goal of this research is to obtain the optimum angle of attack for this particular type of airfoil within a precise range. The Reynolds-Averaged Navier-Stokes (RANS) technique of Computational Fluid Dynamics (CFD) has been employed to examine the flow where the Reynolds number is in the range of 105 to 3x106 and also for the angles of attack from 0° to 20°. These are the typical flow conditions mostly encountered in the real applications of wind turbine blades. The turbulent flow is modelled by means of the Spalart-Allmaras turbulence model since its capability of simulating aerodynamic flows. The ratio of the lift force to the drag force acting on the airfoil has been chosen as a control parameter since the lift force increases the power generated by the turbine, whereas the drag force negatively affects the performance. The present numerical result shows that the maximum lift to drag ratio is observed between 2.5° and 3.5°, depending on the Reynolds number.

Commissioning of the World's First Full-Scale MW-Class Superconducting Generator on a Direct Drive Wind Turbine

High temperature superconducting (HTS) generators could enable a lightweight and cost-effective direct drive (DD) wind turbines with large power ratings. The EU-funded EcoSwing project successfully demonstrated the world's first full-scale MW-class HTS generator on a commercial DD wind turbine. This paper focuses on the commissioning of the EcoSwing HTS generator on the wind turbine. The commissioning campaigns, including the rotor cool-down, excitation of the HTS field winding, and the power production of the generator, are presented in the paper. In the testing period, the generator was grid-connected for more than 650 hours and accumulatively produced more than 600 MWh to the grid. The target output power of the 3 MW class was reached. Throughout the real-life testing on the wind turbine, the generator performed well from the electromagnetic, thermal, and mechanical perspectives. Moreover, the generator even sustained three sudden short circuits in the converter system. The work reported has shown that HTS generators are technologically feasible for wind turbine applications, and the technology readiness level of HTS wind turbine generators has been improved to 6 $\sim$ 7 for the first time.

Safety Design of a Hybrid Wind-Solar Energy System for Rural Remote Areas in Costa Rica

Although several kinds of energy generation systems have been investigated and introduced in Costa Rica, none were made on systems that use more than one energy source. The present work proposes a safety design of a hybrid wind-solar renewable energy system, designed to cover the energy demand in a governmental free housing at Martina Bustos, Liberia, Costa Rica. Twelve scaled models were designed. These are composed of a pole and one to four solar panels. Two commercial wind turbines, Airdolphin Mark-Zero/Pro and Zephyr 9000 were used to experimentally measure wind force on a wind tunnel at the Wind Engineering Research Center of the Tokyo Polytechnic University. Further, allowable stress design was calculated to determine the tower resistance to local buckling. Present results indicate that towers with 200 mm of the circumference and steel plates with 4.5 mm to 8 mm of thickness are considered safe from local buckling according to Japanese Industrial Standards. Energy generation calculation results show that four of the proposed models generate more than the average energy needed to supply electricity during a year at Martina Bustos to the specific house design.

Design and Implementation of a Wind Turbine Emulator Using an Induction Motor and Direct Current Machine

The study deals with the application details and validation of a wind turbine emulator (WTE) consisting of a user interface, 1.5kW squirrel-cage induction motor (IM) and separately excited direct current machine (DCM). To this end, an induction motor and direct current machine are mechanically coupled to behave like wind turbine. Thus, by controlling the asynchronous motor over wind data, the shaft of the asynchronous motor rotates like the high turbine shaft of the wind turbine and emulates the wind turbine in the laboratory environment. The user interface includes 12 commercial wind turbines with similar characteristics. The user selects the wind data for a day, then selects the wind turbine and operates the system. The system generates reference speed information in accordance with the user's preferences. The WTE calculations are performed on a PC and 32 bit ARM cortex board, both connected on UART. The generated speed information is applied to the frequency converter via the PI control technique and the induction motor is driven according to the reference speed. The purpose of the study is the hardware implementation of a wind energy conversion system for control and online monitoring in a laboratory environment. The system will allow testing various wind data and performing efficiency analyzes at any time and will enable the testing of small-scale power converters for wind power systems.

Ground Testing of the World's First MW-Class Direct-Drive Superconducting Wind Turbine Generator

The EU-funded EcoSwing project addresses the world's first full-scale direct-drive (DD) high temperature superconducting (HTS) wind turbine generator. Before the generator was installed on a commercial wind turbine, the generator had been tested on the ground at the Dynamic Nacelle Testing Laboratory (DyNaLab) in Fraunhofer Institute for Wind Energy Systems (IWES), serving as an experimental validation of the generator design. This article is centered on the ground testing of the EcoSwing HTS generator, which includes corresponding tests for validating the generator's cryogenic design and electromagnetic performance. Despite one HTS coil with a defect limiting the operating current significantly, partial power production up to 1 MW at 14.5 rpm was reached. The critical auxiliary systems, i.e., vacuum system and rotary helium coupling, behaved as expected or even better than anticipated. The work reported in the article successfully validates the generator design, and also provides firsthand information prior to installing and testing the HTS generator on the wind turbine.

Designing and Basic Experimental Validation of the World's First MW-Class Direct-Drive Superconducting Wind Turbine Generator

High temperature superconducting (HTS) technologies are expected to be a key enabler for lightweight and cost-effective direct-drive (DD) trains for large wind turbines. This paper reports the designing and basic experimental validation of the world's first full-scale DD HTS generator demonstrated on a commercial wind turbine. The HTS generator has its rotor with an HTS field winding working below 30 K, which is achieved by using off-the-shelf Gifford-McMahon cryocoolers. The stator of the generator is essentially conventional, except that the armature winding has four segments to limit fault torques in case of sudden short circuits due to converter failures. Compared to an existing DD permanent magnet generator on the turbine, the air gap shearing stress of the HTS generator is doubled, and the weight is reduced by 24%. The overall design requirements from the turbine integration perspective, as well as the topological considerations, are first described in this paper. The electromagnetic and cryogenic designs are then presented, followed by performance testing of HTS coils. The basic experimental validation shows that the cryogenic design is satisfactory and the measured no-load voltage matches the finite element calculation very well.

Wind Energy Potential Assessment and Wind Turbine Performance Investigation in the Cotonou Coast (Benin Republic)

This paper presents a study of the monthly variability of wind energy potential at several heights and an investigation of the best fitting commercial wind turbine in the Cotonou coast (Benin Republic). The monthly Weibull parameters are calculated at 10 m and extrapolated at 30 and 50 m heights. The monthly Weibull wind power density and the wind speed carrying maximum energy are calculated at 10, 30 and 50 m. We showed that wind resource in the Cotonou coast is favorable for wind energy production at 30 and 50 m heights. The capacity factor of selected commercial wind turbines is calculated to investigate the best fitting wind turbine in the Cotonou coast. It turns out that Polaris 19-50 is the best fitting wind turbine in the selected turbines with a mean capacity factor of 0.49.

Machine learning and geographic information systems for large-scale wind energy potential estimation in rural areas

Clean, safe, affordable and available in the long-term, wind is one of the most promising sources of renewable energy. Its optimized and profitable use, however, requires an estimation of the potential in locations of interest, given its very volatile behavior in various settings. In the present study, we propose a methodology using a combination of Machine Learning (Random Forests), Geographic Information Systems and wind parametric models to estimate the large-scale theoretical wind speed potential in rural areas over the entire Switzerland. The monthly wind speed over rural areas is estimated based on wind speed measurements and several meteorological, topographic, and wind-specific features available accross the country. Wind speed values and their associated uncertainty are computed at the scale of 200 x 200 [m2] pixels covering the territory, at a typical height for rural commercial wind turbine installation, that is, z=100m. The developed methodology, is, however, applicable to any large region, given the availability of data of interest. The results show that in the case of Switzerland, wind turbines could approximately represent an non-negligible installed power capacity of, for each pixel and for each turbine installation, on average 80 kW in Swiss rural areas, and up to 1600 kW in most suitable pixels.

Analysis of Wind Data and Assessment of Wind Energy Potential in Lamhiriz Village, Morocco

Morocco has pursued an ambitious policy aimed at boosting renewable energies in the country. On this basis, we have examined the possibility of using wind turbines to generate electricity in Lamhiriz village in the south of Morocco, known for its strong winds. The wind speeds were statistically studied using the data recorded over one-year period collected from the mast which contains a set of measuring instruments at different altitudes. Based on several studies, we selected Weibull distribution to model the wind speeds, and we used the empirical method to estimate the scale and the shape parameters. Thereafter, a detailed analysis of seasonal and annual wind direction was presented. From the obtained results, the available energy density in this area is assessed by using WAsP software. Then, six commercial wind turbines of various sizes between 300 and 1300 kW were technically evaluated for electricity generation in Lamhiriz village by calculating their capacity factors and annual energy outputs. The results showed that the site under study is an adequate location for any of the adopted wind turbine models, where the annual energy output ranges from 1.44 to 6.75 GW h. Therefore, we can conclude that Lamhiriz have an attractive economical potential for developing large wind turbine farms.

Adaptive Machine Learning Approach for Fault Prognostics based on Normal Conditions - Application to Shaft Bearings of Wind Turbine

Prognostics can enhance the reliability and availability of industrial systems while reducing unscheduled faults and maintenance cost. In real industrial systems, data collected from the normal operation conditions of system is available, but there is a lack of historical degradation data is often unavailable. Hence, this paper proposes a general data-driven prognostic approach dealing with the lack of degradation data in the offline phase. First, features are computed on the collected raw signal, then One Class Support Vector Machine (OCSVM) is used to detect the degradation, this anomaly detection method is trained using only normal operation data. Then, features are ranked according to the selection criteria. The feature having the highest score is chosen as Health Indicator (HI). Finally an adaptive degradation model is applied for the prediction of the degradation evolution over time and Remaining Useful Life (RUL) estimation. The proposed approach is validated using run-to-failure vibration data collected from a high speed shaft bearings of a commercial wind turbine.

Qatar’s Wind Energy Potential with Associated Financial and Environmental Benefits for the Natural Gas Industry

This study analyzes the possibility to use the wind’s kinetic energy to produce electricity in Northern Qatar for the natural gas processing industry. An evaluation of the wind potentiality is performed based on a thorough analysis of parameters such as wind speed and direction, temperature, atmospheric pressure, and air density. In addition, based on the measured parameters, a commercial wind turbine is selected, and a case study is presented in order to quantify the energy that a wind farm could produce and its environmental benefits. Furthermore, an economical assessment is made to quantify the repercussions that it could produce if this wind farm substitutes a fraction of the energy demand (within the oil and gas field) that is currently generated by traditional hydrocarbons. The results indicate that the environmental parameters, led by a 5.06 m/s wind speed mean, allow the production of wind energy in the area with an annual CO2 savings of 6.813 tons in a 17 MW wind power plant. This enables Qatar to reduce its internal oil and gas consumption. As a result, the amount of hydrocarbon (natural gas) saved could be used for exportation purposes, generating a positive outcome for the economy with a cost savings of about 3.32 million US$ per year through such a small size wind power plant. From the energy production point of view, the natural parameters enable a single wind turbine to produce an average of 6995.26 MWh of electricity. Furthermore, the wind farm utilized in the case study is capable of generating an average of 34.976 MWh in a year.