Types Of Wind Turbines Research Articles

Enhancing the performance of Savonius rotor using tiered-height zigzag patterns in concave surface

A technique to reduce CO2 emissions from the use of fossil fuels is to use clean energy. One of them is wind energy, which is generated by a wind turbine. Savonius, a type of vertical axis wind turbine, is a small-scale energy conversion device suitable for low wind speeds, such as those characteristic of Indonesian wind speed. The objective of the current study was to analyze the impact of implementing a tiered-height zigzag pattern on the concave surface of the Savonius blade. The zigzag angle operates to direct the wind toward the reverse blade, consequently augmenting the pressure on the reverse blade. In addition, the tiered-height zigzag pattern in the concave surface increases the area of the turbine that is in contact with the wind, which in turn generates more energy. This study used an open-type wind tunnel to conduct experiments as the primary technique of investigation. Its performance was assessed in terms of power and torque coefficients. Additionally, experiments were conducted with other standard semi-circular blades to get a direct comparison. According to the findings of the experiments, incorporating a tiered-height zigzag pattern into a concave surface may produce a power coefficient (Cp) that is 16 % higher than that of a semi-circular. The highest Cp was 0.286 at a TSR of 0.55 and U = 6 m/s. In this case, the Savonius wind turbine's ability may be elevated by including a tiered-height zigzag pattern in the Savonius concave surface.

Numerical Investigation on Aerodynamic Performance of Helical Savonius Rotor Inspired by Natural Shapes

There have been extensive studies conducted on Horizontal Axis Wind Turbines (HAWT) at relatively moderate to high wind speed regions. However, such detailed investigations for Vertical Axis Wind Turbines (VAWT), specifically for low wind speed terrains are amply reported. This motivates us to conduct research to explore possibilities in improving performance of VAWT in low wind speed terrains, which is attempted in the present work. This is required due to the fact that most of regions do not have sufficient extractable wind energy due to low speeds. VAWTs can perform at such low wind speed, but are less efficient. Improving efficiency of VAWT will solve the purpose. Hence, the present study is aimed at finding the performance characteristics of VAWT for low Wind speed configurations. Various parameters affecting power generation are investigated. Numerical analyses on various configurations are conducted to study the effects of twist angle, free stream velocity, number of blades. Computational results obtained have been in good agreement with the established results for semi-circular Savonius rotor profile. The results suggest that for low wind speed terrains, there is a need to explore the combination of lift and drag type of profiles, which could be used for the utilization of available wind power. Hence, naturally inspired shapes (profiles) were investigated for the possible solution of combined lift and drag type wind turbines at low speeds. The blade shape for such combined lift and drag type wind turbine were deduced from the available literature. It is well established that the naturally inspired shapes as noted in sea conch follow golden ratio in its contours. The present study provides an insight on the characteristic curves of VAWT for low wind speed terrains, effects of various geometric and flow parameters suitable for low wind speed terrains.

Optimal floating offshore wind farms for Mediterranean islands

Offshore wind will play an important role in achieving the Green Deal's goals of green transition and renewable energy generation. The European Union (EU) has launched an initiative to support a clean energy transition towards sustainable and renewable energy production in the EU islands. In fact, the Mediterranean islands obtain most of their energy supply from imported fossil fuels, making electricity costs generally very high due to their remote location. In this paper, we compare the optimal offshore wind farm layout, type and number of wind turbines for four selected sites next to Mediterranean islands. Each layout is evaluated in terms of levelised cost of energy, taking into account aerodynamic wake and transmission losses in the productivity estimation and a detailed cost model. Aerodynamic losses are modelled using a Jensen kinematic wake model and an area overlapping model to consider partial wake shadowing between wind turbines, while transmission losses are estimated as Ohmic losses of the inter-array and export transmission cables. Compared to the state-of-the-art PyWake code, the in-house MATLAB wake model demonstrated higher computational efficiency and is integrated into an efficient optimisation algorithm consisting of several iterations of the Interior-point optimisation algorithm. Results show that offshore wind turbines can provide renewable energy at a competitive price, especially at the most energetic site with an LCOE about 80 €/MWh. The normalised optimal LCOE and capacity factor as a function of the number of wind turbines are not significantly influenced by the chosen location and reach a maximum difference of 2–3 %, showing that they mainly depend on the type of wind turbine. The lowest optimal LCOE depending on the number of wind turbines is reduced by about 10 % and 25 % by the higher rated wind turbine.

An optimization study of passive flow control mechanism for a seashell-shaped wind turbine

Small wind turbines have a lot of promise in areas that are remote from the power grid. For such small-scale applications, such as off-grid electricity, a spiral wind turbine (SWT), a novel type of horizontal-axis wind turbine, may be employed. Placing wind turbines within a duct is one potential method for increasing the efficiency of wind energy harvesting in low-wind urban locations. In this work, a shroud with a flange at its outlet is created using an optimization approach that attempts to maximize the coefficient of power (CP), which improves SWT performance. An evolutionary algorithm over a Kriging interpolative model serves as the optimizer in use. The shroud's shape is determined using a series of straight lines. Using the commercial code program ANSYS-FLUENT, the Reynolds-averaged Navier-Stokes (RANS) equations are solved along with the SST k–ω turbulence model to determine the turbine CP. The computational results are validated and confirmed with previously published results. The optimal shroud design introduced significant improvements in the CP when applied to the SWT, resulting in a maximum CP of 0.967 (at λ = 3.25), which is 3.6 times the maximum CP of the bare SWT (CP = 0.2668 at λ = 2.5).

Using 2-bladed Savonius rotor to harvest highway wind energy at airport: A case study

ABSTRACTThe Savonius wind turbine (SWT) is a famous type of vertical axis wind turbine (VAWT) that accepts wind from all directions, particularly suitable for various applications including the design of small-scale wind turbines. This study evaluates the potential installation of a simple 2-bladed SWT on Queen Alya’ airport highway, Amman, Jordan. The strategic objective of this work was to design and install the SWT prototype at different sites along the airport road to define the most efficient location for capturing wind energy. The SWT rotor was fabricated via galvanized steel sheets. The self-starting ability of the rotor was examined by determining the torque coefficient at different angles of attack. The field tests were carried out by employing the turbine at three different locations along a six-lane highway (including the left, right, and middle sides of the highway). It was found that the proposed turbine has a cut-in wind speed of 2.5 m/s. Furthermore, the torque coefficient values indicated that the proposed rotor has a strong self-starting capacity. Field studies also revealed that the rotational speed of the turbine differs at various positions of the wind turbine. In addition, the results highlighted the significance of wind directions relative to vehicle directions for generating wind power on highways. The established Savonius rotor exhibited a maximum coefficient of performance of 0.25 with operational TSRs up to 0.7. Overall, a maximum enhanced rotational speed of about 53% was attained by positioning the turbine in the middle of six-way-lane highways.

Ортогональные ветроэнергоустановки для нефтегазопромысловых объектов на суше и на море

Wind and solar power plants for autonomous power supply of small oil and gas facilities with a capacity of no more than 20 kW, wind power plants in their composition – 10 kW with a power factor (energy efficiency) of no more than 0.35–0.45 are considered. An improved design of an orbital wind power plant based on a combined H-Darye-Savonius rotor has been developed. Experiments on the laboratory installation showed that the maximum values of the power factor reached 0.60, which is much higher than that of the rotors of known types of wind turbines. The values of the CRDS power factor are calculated for various geometric dimensions of the N-Darye and Savonius rotors included in its composition. With an increase in wind speed to the nominal value of 9.0 m/s for small and medium power wind turbines and a rotor diameter of 15.0 m, the combined rotor power reaches almost 60 kW. The proposed orthogonal wind power plants with a nominal capacity of up to 60 kW will be able to be used together with other power plants for autonomous power supply at oil and gas field facilities on land and at sea, and in the future at intelligent fields.

Soil deformation and failure analysis of suction caisson in marine clay under combined loading

The suction caisson is a typical offshore wind turbine(OWT) foundation, which is widely used due to its low construction cost and simple structure. However, the soil deformation and failure mechanisms of the suction caisson under combined loading are very complex and variable, which are different from those of the embedded foundation. In this study, the finite element method is adopted to capture the soil deformation and failure mechanism of a typical suction caisson under combined loading. A series of finite element models of suction caisson were performed to investigate the effects of the soil and foundation parameters on the failure and deformation behavior of the foundation, and a framework for calculating the bearing performance of suction caisson was provided. The results show that the failure modes of a suction caisson can be depicted in four patterns, namely internal Hansen, scoop-slide, scoop and slide. The deformation and failure characteristics of the soil are closely related to the ratio of M/HD, while less influenced by the interface condition, length-dimeter ratio, vertical loading and soil strength profile. The results are of great benefit in understanding the bearing characteristics of the suction caisson under combined loading for the promotion of the foundation.

Example of Matlab/Simulink Tool Usage for Evaluation of Wind Turbine Operation During Voltage Regulation and Reactive Power Regulation

Abstract In this paper, the types of wind turbines are listed and described, with the emphasis on horizontal-axis wind turbines. The parts are explained in more detail, the criteria for the selection of the wind turbine generator and the methods of managing the wind turbine are defined. In the Matlab/Simulink programming environment, a model of an electric power network with a wind farm was created, and the characteristics of the operation of wind turbines under normal and fault conditions were presented.

Convolutional neural network–based structural health monitoring framework for wind turbine blade

Wind energy is a renewable energy source with a significant impact on the date for harnessing it. Different types of wind turbines (WTs) are being built to generate affordable, dependable, and eco-friendly renewable wind energy. Over time, cracks are found to be developed in the blades of the WTs, which is considered the most common type of damage that ultimately causes the catastrophic failure of the structures. This study aims to develop a structural health monitoring (SHM) framework for localizing cracks of a WT blade using a convolutional neural network (CNN)–based deep learning algorithm. With that objective, the NACA (National Advisory Committee for Aeronautics) 63-412 profile (WT blade) of length 29 m was modelled in finite element analysis (FEA) ANSYS 2022 R2. A crack is introduced to the model by making a groove at different blade locations. The mode shape and natural frequencies are obtained and validated with those reported in the literature. Further, the blade is excited by an impact load applied at the tip of the blade, and acceleration time histories are collected. The acceleration time history data are converted to scalogram images and fed into the CNN algorithm for damage classification and localization. In this study, the concept of class activation maps is also utilized for visual representations of the input images’ areas that significantly influence a class’s classification score. The classified results show that using CNN can successfully localize the region of the cracks and motivate us to examine it on a laboratory-based model.

Simulation of electric energy potential from wind speed in the San Andrés island

In this work, the wind resource of the islands of San Andrés was studied during the years 2011 - 2012 to determine its electric energy potential. Wind speed and direction taken from the mereology station of IDEAM located at the Gustavo Rojas Pinilla airport were used for modeling the electric energy obtained from different types of wind turbines and their location height. The maximum energy obtained was 5496.6 MWh/year using a wind turbine of 3.75 MW power. However, the economic analysis indicated that Neg Micon's 2.75 MW wind turbine has the lowest generation cost of US$ 0.04/kWh and an energy production of 4,919.1 MWh/year. According to this, for a sale price of US$ 0.14 /kWh, the net present value (NPV) would be US$ 5,928,594.9 the internal rate of return (IRR) of 16%, and the investment recovery time (TRI) of almost 4.1 years, making the wind project attractive for investors.

Modeling of Wind Turbine Interactions and Wind Farm Losses Using the Velocity-Dependent Actuator Disc Model

This paper analyzes the interaction of wind turbines and losses in wind farms using computational fluid dynamics (CFD). The mathematical model used consisted of three-dimensional Reynolds-averaged Navier–Stokes (RANS) equations, while the presence of wind turbines in the flow was simulated as additional source terms. The novelty of the research is the definition of the source term as a velocity-dependent actuator disc model (ADM). This allowed for modeling the operation of a wind farm consisting of real wind turbines, characterized by power coefficients Cp and thrust force coefficients CT, which are a function of atmospheric wind speed. The calculations presented used a real 5 MW Gamesa turbine. Two different turbine spacings, 5D and 10D, where D is the diameter of the turbine, and two different locations corresponding to the offshore and onshore conditions were examined. The proposed model can be used to analyze wind farm losses not only in terms of the geometric distribution of individual turbines but also in terms of a specific type of wind turbine and in the entire wind speed spectrum.

An Investigation on the Teeth Crowning Effects on the Transient EHL Performance of Large-Scale Wind Turbine Spur Gears

Crowning is applied to wind turbine gears, including spur gears, to ensure adequate stress distribution and contact localization in wind turbine main gearbox gears to improve the gear performance in the presence of misalignments. Each gear tooth is crowned along the face width using a parabolic curve that graduates from a maximum height at the edges and vanishes at the center of the tooth flank. This crowning transfers the elastohydrodynamic contact problem from a line to a point contact case where the surface curvatures and pressure gradient are considered in both directions of the solution space. A wide range of longitudinal crowning heights is considered in this analysis under heavily loaded teeth for typical large-scale wind turbine gears. Furthermore, the variation in the velocities is considered in the analysis. The full transient elastohydrodynamic point contact solution considers the non-Newtonian oil behavior, where the numerical solution is based on the finite difference method. This work is focused on the evaluation of the effectiveness of teeth’s longitudinal crowning in terms of the consequences on the resulting pressure distribution and the corresponding film thickness. The modification of the tooth flank significantly elevates the film thickness levels over the zones close to the tooth edges without a significant increase in the pressure values. Moreover, the zone close to the tooth edges from both sides, where the pressure is expected to drop to the ambient pressure, is extended as a result of the flank modification.

Refined Equivalent Modeling Method for Mixed Wind Farms Based on Small Sample Data

For equivalent modeling of mixed wind farms (WFs), existing clustering indicators cannot consider the complex coupling characteristics between different types of wind turbines (WTs). In this paper, a refined equivalent modeling approach based on artificial intelligence technology is proposed. Firstly, the electromechanical transient performance of mixed WFs is analyzed. The WT type, wind speed and direction, and voltage dip are considered the dominant factors affecting the external dynamic response of mixed WFs. Secondly, the equivalent node model is established, including the selection of independent and dependent variables. Then, the multiple artificial neural networks (ANNs) are trained one by one based on small sample data, to fit the nonlinear relationship between the dependent variables and the independent variables. Finally, the dynamic response of the power systems with a mixed WF is simulated in the MATLAB platform. A comparison of the errors in electromechanical phenomena demonstrates that the proposed model can reflect the external characteristics of the test mixed WF in different wind conditions and voltage dips.

Analysis of the Effects of Fluctuating Wind on the Aerodynamic Performance of a Vertical-Axis Wind Turbine with Variable Pitch

The wind turbine with a variable-pitch vertical axis is a novel type of small wind turbine with great development potential in the field of wind power generation. This study assessed the aerodynamic performance of a two-dimensional variable-pitch vertical-axis wind turbine (VAWT) under fluctuating wind conditions (sinusoidal-type fluctuations with an average velocity of 6 m/s) using the finite-volume method and the RNG k−ε turbulence model. The effects of the fluctuating inflow amplitude (Uamp), frequency (fc), and mean tip speed ratio (λmean) on the power coefficient of the wind turbine are analyzed. The results show that a maximum power coefficient of 0.33 is obtained when the inflow amplitude reaches 50% of the average velocity. The power coefficient initially increases and then decreases with the increase in the fluctuating inflow frequency, reaching a maximum value of 0.32 at fc=0.45 Hz. Furthermore, the power coefficient reaches its maximum value of 0.372 at λmean = 0.5. Proper orthogonal decomposition (POD) is used to decompose and reconstruct the flow field under both fluctuating and uniform inflow conditions. A comparison of the POD analysis between the two conditions shows that the energy distribution is more dispersed under the fluctuating inflow condition and reconstructing the flow field under fluctuating inflow conditions requires more POD modes than that under uniform inflow conditions.

Numerical Study of Taper Type Turbine Blade at a 5° Angle

Renewable energy has emerged as a critical solution to the global challenges of climate change and continued reliance on fossil fuels. Wind turbines play an important role in this context as sources of clean energy that can meet electricity needs with minimal environmental impact. With its vast wind potential, Indonesia has a unique opportunity to drive the transition to renewable energy. As a result, a thorough understanding of wind turbine technology and the factors influencing its efficiency is becoming increasingly important. This article uses Q-Blade software to simulate the effect of blade angle on a taper type wind turbine with a 5° angle. The main findings show that the angle of attack has a significant impact on wind turbine performance. According to the dynamic pressure distribution on the airfoil profile, the optimal angle of attack peaks at half chord, resulting in maximum lift. Despite the fact that the power coefficient (Cp) value is slightly lower than the theoretical limit of the Betz principle This turbine can convert approximately 30.7% of the wind's kinetic energy into mechanical power. The findings of this study provide important information for the development of more efficient and sustainable local wind turbine technology in Indonesia, which is consistent with the vision of energy sustainability and Indonesia's role in global renewable energy. Developers can design more efficient wind turbines, reduce global carbon footprints, and support the transition to environmentally friendly renewable energy with a better understanding of angle of attack. This article is an important step toward a cleaner, more sustainable future in energy provision for Indonesians and the rest of the world.

Pengembangan E-Modul Turbin Angin (Savonius Heliks) dengan Model 4-D Pada Mata Kuliah Energi Terbarukan di Prodi Pendidikan Teknik Mesin Universitas Sebelas Maret Surakarta

Renewable energy technologies are currently being developed, one of which is wind turbines. There are two types of wind turbines, namely the vertical axis and the horizontal axis. One of the horizontal wind turbines is the helical savonius. The development of this technology can help the development of renewable energy. The Mechanical Engineering Education study program is testing wind turbines to help students understand wind turbine technology. Through this research a practicum module will be created to assist students in carrying out wind turbine practicum.This electronic module validates the material and media. The results of the material validation stated the suitability of the material in accordance with the material on wind turbines that had been taught in wind turbine courses. The results of the media validation state that the design is attractive and easy to read so that students can understand the electronic module.

Multi-Agent Reinforcement Learning Control of a Hydrostatic Wind Turbine-Based Farm

This paper leverages multi-agent reinforcement learning (MARL) to develop an efficient control system for a wind farm comprising a new type of wind turbines with hydrostatic transmission. The primary motivation for hydrostatic wind turbines (HWT) is increased reliability, and reduced manufacturing, operating, and maintaining costs by removing troublesome components and reducing nacelle weight. Nevertheless, the high system complexity of HWT and the wake effect pose significant challenges for the control of HWT-based wind farms. We therefore propose a MARL algorithm named multi-agent policy optimization (MAPO), which allows agents (turbines) to gradually improve their control policies by repeatedly interacting with the environment to learn an optimal operation curve for wind farms. Simulation results based on a wind farm simulator, FAST.Farm, show that MAPO outperforms the greedy policy and a popular learning-based method, multi-agent deep deterministic policy gradient (MADDPG), in terms of power generation.

Mechanism Analysis of Wind Turbine Var Oscillations

Electromagnetic transient simulation of parallel connected 4-MW type-3 wind turbines based on original equipment manufacturer's real-code turbine model shows 1.2-Hz turbine-turbine oscillations in reactive power. This letter reveals why such oscillations occur in the individual var measurement, while being insignificant in the total var measurement, regardless of the varying grid impedance. We adopt two analysis approaches: open-loop single-input single-output analysis and network decomposition. The two approaches differ in their treatment of turbine-network interaction. The open-loop analysis shows that the turbine-turbine oscillation mode is due to an open-loop system pole being attracted to an open-loop system zero. Furthermore, we use network decomposition method to explain why this mode is observable in individual vars while not observable in the total var. The entire system of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n$</tex-math></inline-formula> -turbines can be viewed as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n$</tex-math></inline-formula> decoupled circuits. For the two-turbine case, the system has an aggregated mode and a turbine-turbine oscillation mode. The aggregated mode is associated with a circuit associated with the total var, while the turbine-turbine oscillation mode is associated with the var difference and is insensitive to the grid parameters.

Low-voltage ride-through capability improvement of Type-3 wind turbine through active disturbance rejection feedback control-based dynamic voltage restorer

Abstract Disconnections due to voltage drops in the grid cannot be permitted if wind turbines (WTs) contribute significantly to electricity production, as this increases the risk of production loss and destabilizes the grid. To mitigate the negative effects of these occurrences, WTs must be able to ride through the low-voltage conditions and inject reactive current to provide dynamic voltage support. This paper investigates the low-voltage ride-through (LVRT) capability enhancement of a Type-3 WT utilizing a dynamic voltage restorer (DVR). During the grid voltage drop, the DVR quickly injects a compensating voltage to keep the stator voltage constant. This paper proposes an active disturbance rejection control (ADRC) scheme to control the rotor-side, grid-side and DVR-side converters in a wind–DVR integrated network. The performance of the Type-3 WT with DVR topology is evaluated under various test conditions using MATLAB®/Simulink®. These simulation results are also compared with the experimental results for the LVRT capability performed on a WT emulator equipped with a crowbar and direct current (DC) chopper. The simulation results demonstrate a favourable transient and steady-state response of the Type-3 wind turbine quantities defined by the LVRT codes, as well as improved reactive power support under balanced fault conditions. Under the most severe voltage drop of 95%, the stator currents, rotor currents and DC bus voltage are 1.25 pu, 1.40 pu and 1.09 UDC, respectively, conforming to the values of the LVRT codes. DVR controlled by the ADRC technique significantly increases the LVRT capabilities of a Type-3 doubly-fed induction generator-based WT under symmetrical voltage dip events. Although setting up ADRC controllers might be challenging, the proposed method has been shown to be extremely effective in reducing all kinds of internal and external disturbances.

Fluid dynamic design of a vertical axis wind turbine rotor under low wind speed

The design of the rotor geometry of a vertical axis wind turbine (VAWT) type H, for power generation at low wind speeds, is presented. The computational simulation allowed us to establish that the NACA 0018 profile offers a better ratio of lift and drag coefficients in contrast to NACA 0021 and NACA 0025, so this geometry was selected as the working profile. Then, to generate a power of 30W, the dimensions of the airfoil chord, the radius, and the rotor's height were found from the blade tip speed ratio (TSR) values and the power coefficient. The results obtained indicate that the appropriate dimensions of the rotor at low-speed conditions are, a diameter of 2 m, a height of 2.16 m, and several blades of 3, for a rotation speed of 9 rad/s. Finally, an agreement was found between the angular velocity calculated theoretically, for the proposed rotor dimensions, and that obtained from the ANSYS-CFD simulation.