Unconventional Wind Research Articles

Investigating the effectiveness of a mobile wind turbine generating electricity from vehicle air movement

This study presents an evaluation of the effectiveness of a portable wind generator designed to harness wind flow generated by moving vehicles for electricity production. With a growing emphasis on renewable energy sources and the need for sustainable power solutions, innovative approaches such as utilizing vehicle-induced wind currents have gained attention. The portable wind generator under examination is engineered to capture airflow from passing vehicles and convert it into electrical energy. Through a combination of field experiments and theoretical analysis, the performance and efficiency of the device were assessed under various environmental and traffic conditions. Factors such as wind speed, direction, and vehicle velocity were considered in the evaluation process. The results indicate promising potential for the portable wind generator as a supplementary power source, particularly in environments with high vehicular traffic. However, challenges such as variability in wind patterns and optimal positioning of the generator remain areas for further investigation and refinement. Overall, this study contributes to the understanding of utilizing unconventional wind resources and provides insights into the practical implementation of mobile wind energy technology for sustainable electricity generation.

AC Losses Analysis and Design Guidelines for Hairpin Windings With Segmented Conductors

In the last years, hairpin windings are amongst the most studied and implemented winding topologies to increase torque and power densities of electrical machines, especially in the traction field. However, their main drawback remains the elevated ohmic losses generated at high frequency operations. Recently, hairpin windings with segmented conductors have been proposed to overcome this challenge, but an analytical model to predict the losses in such unconventional winding is missing, as well as a critical analysis on the extra manufacturing complexities needed. In this paper, first a simple analytical formulation for the estimation of AC losses in segmented hairpin conductors is proposed, developed and validated at various operating frequencies, both through finite element analyses and experimental measurements. Then, an in-depth analysis of the main advantages and disadvantages of this winding topology is proposed with the aim at providing guidelines and recommendations for their practical realization, adopting standard methodologies for their connection and transposition.

A Novel Three-Layer Symmetry Winding Configuration for Five-Phase Motor

This paper presents a new three-layer, five-phase winding configuration theory of unconventional slot-pole combinations by each layer of winding for a phase vector correction, three layers of winding superimposed together to achieve the results of three-phase symmetry. Since the single-layer unconventional winding has to have an empty slot to meet its symmetry, based on the characteristics of single-layer winding, the unconventional winding design is carried out. Based on the simulation comparison between the single-layer unconventional winding and double-layer unconventional winding, a three-layer, nine-phase unconventional winding is proposed, which is based on the theory of single-layer unconventional winding, and three layers are staggered and stacked to realize nine-phase winding, which not only increases the utilization rate of the winding slot but also improves the fault tolerance performance. In addition, a 105-slot, 20-pole, three-layer, five-phase motor is proposed for a winding configuration and performance analysis to achieve both low torque pulsation and high fault tolerance.

The Effect of Different Rotational Speeds of a Cylinder on Magnus Wind Turbine Performance

The current conditions of global technology are moving towards more renewable and sustainable energy, with each functional society completely dependent on electricity. Electricity has become fundamental in daily life. Wind is a vital green energy source that can be harvested naturally and sustainably, despite varying temperatures that occur due to the uneven solar heating of the Earth's surface. Therefore, this study has relied on unconventional wind turbines that aim to obtain largest possible energy from low wind speeds. In order to achieve this purpose, the experiment has required using of a different type of wind turbine, which is known as Magnus wind turbine. The Magnus effect involves utilizing rotating cylinder blades to harvest as much wind energy as possible, by generating aerodynamic forces perpendicular to the coming wind. Furthermore, most endeavors to increase the performance of wind turbines have followed traditional methods, in contrary to the bespoke method, which also consists of adding a support structure to the rotating cylinder in order to reduce cylinder vibration during rotation. However, there is not enough research on changing the cylinder rotation and the efficiency of the wind velocities at the low level. Based on this shortcoming, this study will provide information regarding the different speeds of cylinder rotation and the amount of power gained for each of them.

Generating unconventional wind flow in an activelycontrolled multi-fan wind tunnel

In this study, an iteration-based method to simulate two typical examples of unconventional wind flow in a multi-fan wind tunnel is described: skewed non-Gaussian turbulence and sinusoidal type transient gust. The air flows are generated by 120 actively controlled fans arranged in a 10 wide by 12 high matrix. Time-varying voltages signals can be imported into the fans' servomotors, then corresponding wind flow can be produced in this wind tunnel. At first, the target wind speeds time series are converted to voltages signals, which are input into the fans' motor next, and then the initial wind flow generated can be measured. Then the wind speeds time series to be input are adjusted according to the differences between the target winds speeds and measured flow speeds. The above procedure is iteratively repeated until the measured wind flow is gradually close to the targets. At last, both non-Gaussian turbulence and transient gust can be simulated with satisfied precision after several iterations.

COUNTER-ROTATING DUAL ROTOR WIND TURBINE LAYOUT OPTIMISATION

General energy demand is continuously increasing, thus the energy generating assets need to be optimised for higher efficiency. Wind turbines are no exception. Their maximum efficiency can be determined on a theoretical basis. The limit is approached by researches day by day, utilizing the latest developments in airfoil design, blade structure and new and improved ideas in conventional and unconventional wind turbine layouts. In this paper, we are reviewing the conventional and unconventional wind turbines and their place in smart cities. Then, an unconventional wind turbine design, the CO-DRWT (counter-rotating dual rotor wind turbine) is analysed with a CFD (computational fluid dynamics) code, varying the axial and radial distances between the two turbines. After the simulations, the power coefficients for the different turbine configurations is calculated. At the end of this paper, the simulations results are summarized and consequences are drawn for the CO-DRWT layouts.

An optimum three-stage stator winding connections for wind-driven stand-alone self-excited induction generators for enhanced annual energy output

A special three-phase stator winding consisting of a parallel combination of delta and star is proposed for wind-driven, self–excited induction generators (SEIGs), increasingly used for supplying isolated loads. This winding configuration enables the SEIG to be operated over a wide range of wind speeds, in three stages. The winding is set at parallel delta-star connection at higher wind speeds and then changed to conventional series delta and series star connections at medium and low wind speeds, respectively. An equivalent circuit has been developed for SEIG with this unconventional winding, and the expressions for the evaluation of its performance characteristics have been derived. A method of determining a suitable value of excitation capacitor bank has also been formulated using genetic algorithm. Taking an example of a 2.2 kW, three-phase SEIG, its predetermined characteristics and the corresponding experimental results have been presented. Taking the wind data from an actual wind farm, the annual energy output obtainable from this generator is also estimated. The proposed switching scheme is thus shown to be optimum for covering a wide range of wind speeds. A cluster of several such generators can lead to the establishment of battery charging stations and formation of micro-grids.

Preliminary design of a hydraulic wind turbine drive train for integrated electricity production and seawater desalination

The integration of wind energy to desalinate seawater can address the freshwater scarcity issue and alleviate the environmental impact of desalination. This paper presents the use of the Delft Offshore Turbine, an unconventional wind turbine with hydraulic transmission which can be used to directly drive a seawater reverse osmosis desalination process and to produce electricity with a Pelton turbine. A steady-state model is used to identify the potential regions at which it is possible to operate the system and to propose a system settings for maximising water production. The results show that the proposed system provides up to 300 kW of electricity and can desalinate up to 25 m3/h, at rated operating conditions.

Review on Unconventional Wind Energy

Fossil fuel is the major source of energy and is a fast depleting resource. The phenomenal increase in fossil fuel consumption has adversely affected carbon footprint impacting our environment. With strict environmental regulations in place, the focus towards renewable sources of energy is gaining momentum supported by recent advancement in technologies in wind, hydro and solar. Wind turbines were the first forms of clean energy has seen a major increase in power production. The site restrictions, have limited the wind turbine from being used to its maximum potential. In recent years, the concept of some unconventional methods is being proposed. In this review, the various types of wind turbines are emphasized with their recent advances and depicting the challenges faced in various aspects. The reviews contain details mainly about 4 types of wind turbines i.e. floating offshore wind turbine, airborne wind turbine, highway wind turbine systems and locomotive mounted wind turbine.

Modeling of techno-economic assessment on wind energy potential at three selected coastal regions in Lebanon

In the present paper, the wind speed characteristics of three coastal regions in Lebanon, Beirut, Sidon, and Tripoli, were analyzed using ten statistical distributions. The wind speed data were collected from the meteorological service during a 7-year period (2010–2016).The maximum likelihood method was used to determine the parameters of the distribution functions. For the assessment of the reliability of the distribution functions, the Kolmogorov–Smirnov (KS) statistic was calculated. The wind power density values for the regions were also calculated at various heights using the power law model. The results showed that the wind power density value in the region is considerable and can be exploited using small-scale wind turbines. Moreover, the economic analyses of four wind turbine models of various types and sizes were estimated using the present value cost method. It is found that vertical axis wind turbines (VAWTs) offer the potential to outperform horizontal axis wind turbines in urban environments. VAWTs can handle unconventional wind and at slower speeds, which were found in these regions. Consequently, the Winddam (VWAT) turbine is strongly recommended for installation in the selected regions.

Performance Analysis of Induction Machines with Unconventional Winding Configurations

This paper presents the performance of fractional slots distributed windings (FSDW) and fractional slots concentrated windings (FSCW) of three-phase squirrel cage induction machines. The different windings have been designed and modeled using the same machine physical and electrical parameters. The Finite Element Model (FEM) of the machine for the different windings has been carried out. The results for the machine with FSDW and FSCW are compared to the results of the conventional double layer (CDL) with 8/9 chorded coil.

Finite difference study of unconventional structures of permanent-magnet linear machines for electromagnetic aircraft launch system

This paper deals with the design of an electromagnetic aircraft launch system (EMALS). The system studied is based on a linear permanent-magnet (PM) machine. For the same thermal, geometric, and feeding specifications, original configurations of linear machines have been studied and compared to more classical ones in terms of performance. The work shows that originals structures which use Halbach array configuration in association with unconventional winding strategy can produce very interesting solutions with which to build an EMALS synchronous PM machine.

Innovative Reactive Power Saving in Wind-driven Grid-connected Induction Generators Using a Delta-star Stator Winding Part I: Performance Analysis of the Delta-Star Generator and Test Results

An innovative delta-star three-phase winding, developed earlier for harmonic reduction in 3-phase induction motors, is applied for constant speed grid-connected induction generators. A method has been developed for the prediction of the performance of the generator with such an unconventional winding. It has been demonstrated that with a suitable switching arrangement, the proposed delta-star generator can result in increased real power delivered to the grid and reduced reactive power drawn from the grid, as compared to a fixed stator configuration. A suitable microcontroller-based switching-scheme has also been designed for changing the stator connection according to the wind speed. The facility for using the star mode of the generator while connecting it to the grid with much reduced inrush current is also illustrated.