Small Wind Generator Research Articles

Innovation in clean energy from man-made wind and small-wind generation

The need to reduce global emissions leads us to look for various sources of clean energy. In recent decades, wind technology has advanced significantly, enabling large-scale power generation in both marine and terrestrial environments, as well as the development of mini-wind solutions. However, we often underestimate the capacity of certain human activities and production processes to generate clean energy, wasting their true potential. This work focuses on using artificially generated wind gusts to transform them into clean electricity through small wind turbines. The proposal is developed in four phases: (1) identify activities that generate wind, (2) collect data on wind speed and direction, (3) perform a descriptive statistical analysis of the wind resource, and (4) select the appropriate technology to calculate the electricity generation. The proposal is evaluated using the air flow produced by the air conditioning systems of a data center in Colombia. The results are analyzed from technical, economic, environmental, and political perspectives. Through small wind power, an annual production of approximately 468 MWh is estimated, avoiding the emission of 300 metric tons of CO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{CO}}_2$$\\end{document}.

Small wind in urban sectors: Review of literature and dynamic model implementation

Large industry is focusing on off-shore wind generation solutions which permit extra large turbine dimensions. In an economically recessing situation it may be sensible to underline the good results observed in distributed and local generation. Attending to consumer proximity, cities and urban areas are to be studied. These locations present renewable resource scarcity in general. However, several authors, following the evolution of regulations in countries like UK, present the advantages of small wind. From the point of view of generator concept options experimental comparative analysis’ results are included. Finally, a mathematical model for small radial flux permanent magnet synchronous generators (RF-PMSG) is included and verified by means of a contrasted simulator in Matlab Simulink. The implemented simulator will permit more accurate and analytical comparatives between small wind generator solutions.

Aerodynamic Characterization of a Fan-Array Wind Generator

Experimental assessment of safe and precise flight control algorithms for unmanned aerial vehicles under gusty wind conditions requires the capability to generate a large range of velocity profiles. In this study, we employ a small fan-array wind generator that can generate flows with large spatial and temporal variabilities. We perform a thorough aerodynamic characterization, operating the fans uniformly from low to maximum levels. Particle image velocimetry and hot-wire measurements indicate a jetlike flow with a nearly uniform core, which monotonously contracts in the streamwise direction and the surrounding, growing unsteady shear layers. These complex dynamics result in a limited region with a desired flow profile and turbulence level. The experimental results shed light on the flow generated by a full-scale fan-array wind generator, and they indicate the need for further improvements via properly designed add-ons and dedicated control algorithms.

Implementation and Evaluation of a Low Speed and Self-Regulating Small Wind Turbine for Urban Areas in South Africa

A low-cost small 500W wind generator was used as a basis for the prototype development. The research was primarily focused on the determination of the type of aerofoil for improved rotor blades and pitch angle, and for adapting the number of blades in order to optimize the power output from the prototype, for low wind-speed inland conditions in Soweto. NACA-4412 type aerofoil was chosen as a departure point for the blade design, and a variation of the maximum pitch angle of 6°, 10°, and 12° at an optimum angle of attack of 5°, 7°, and 9° were implemented respectively for Designs 1, 2 and 3. With the Soweto area having an average wind speed of 2.3m/s (8.28km/h), 3-, 5-, and 7-blade sets were subsequently developed, implemented, and tested. Prototype 1 produced a maximum output power of 8.2W at 4.2km/h wind speed. Prototype 2 yielded a maximum output power of 12.5W at 4.2km/h, and Prototype 3, generated a very useful power output of 39.5W during testing. The maximum power output was achieved at an average wind speed of 1.17m/s (4.2km/h). Moreover, the developed prototype designs were also tested for self-regulation in case of high-speed gust conditions. Prototype 3, with a 12° maximum pitch angle during operation in high gust conditions, had its blades control high speed. A drawback pressure occurred on the back side of the blades and tangent drag was developed normally to the blade rotation direction, consequently limiting the maximum speed of the rotor and acting as a self-regulation mechanism with regard to maximum achievable speed. The other two designs suffered from over-speeding tendencies in high gust speed conditions, also causing noise and turbulence.

소형풍력발전을 위한 3상 단일전력단 교류-직류 컨버터

This paper proposes a three-phase single-stage AC-DC converter for the small wind generation system. Input power factor improvement and insulated output can be implemented with the proposed three-phase single-stage AC-DC converter under the wide power generation voltage (80-260 Vac) and frequency (10-42 Hz) in a small wind power generation (WPG) system. The proposed converter is also capable of zero-voltage switching in the primary-side switches and zero-current switching in the secondary-side diodes by phase-shift control at a fixed switching frequency. In addition, it is possible to control a wide output voltage (Vo: 39 VDC-60 VDC) by varying the link voltage and improving the input power factor (PF) and the total harmonic distortion factor (THDi). Simulation and experimental results verified the validity of the proposed converter.

MPPT Solution for Commercial Small Wind Generation Systems with Grid Connection

Power generation using small wind turbines connected to AC grids has been gaining attention and contributions in recent years. As small wind turbines are connected to remote areas as support energy systems, there are not extensive contributions connecting those small turbines to AC grids. This paper presents the integration of a small wind generation system which is AC-grid-connected. The system is composed of a 160 W commercial small wind turbine with a permanent magnet synchronous generator and a 140 W Texas Instruments (Dallas, TX, USA) development kit devoted to connecting photovoltaic panels to AC grids. Several experimental tests were developed to characterize the devices, e.g., to obtain the power–current curves of the synchronous generator. Moreover, a mathematical model of the flyback converter is developed in detail in order to design a new converter controller. All the control capacity of the development kit is used to extract the maximum power of the synchronous generator, to reject the oscillation produced by the inverter and to connect the system to the AC grid. Experimental results show that is possible to integrate these devices to provide energy to power systems with some achievable adaptations.

Control Strategy of PMSG Generator in Small Wind Turbine System

This paper presents a control strategy of turbine directly driven permanent magnet synchronous generator (PMSG) for a small wind generation system. 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. The study methodology is based on defining various study cases combining structural and operational parameters of the wind energy systems. The models of the PMSG, the force commutated rectifier, the DC bus, the buck converter and the inverter are developed and used in the control scheme. The objective of this paper is to compare between tow controls with simulation, and with more description of all the system by developing the technique needed to control the converter. The simulation results will show that the proposed control can operate with a good performance in a stand-alone wind energy conversion system for low power generation applications.

The Potential of Wind Energy as a Source of Renewable Energy in Selected Local Government Areas of Delta State, Nigeria

The wind energy potential of five selected local Government Areas of Delta State, Nigeria was investigated using Exetech 45116 Digital Wind Anemometer and Garmin GPS 111 plus Model. Ten readings of the wind speed data was obtained from five sampled sites located within the selected local government areas. The results revealed that the mean wind speed for Bomadi, Uvwie , Warri South, Warri North, and Warri South West LGAs is 2.36 m/s, 4.50 m/s, 2.19 m/s, 2.05 m/s and 2.5 1m/s respectively. Similarly, the wind power densities (WPD) for the aforementioned areas are 8.03 W/m^2, 44.91 W/m^2, 6.46 W/m^2 5.30 W/m^2 and 9.73 W/m^2 respectively. The data obtained was analysed statistically using linear regression and the results revealed that there is correlation between the wind speed and the temperature with R^2 values 96%, 73%, 55%, 92% and 89% for Bomadi, Uvwie, Warri South, Warri North and Warri South West LGAs respectively. Thus, indicating that wind speed is a function of temperature. In addition, Bomadi, Warri South, Warri North and Warri South West are suitable for small wind generation (domestic use) and this finding is based on the results of the wind speed obtained from the locations. However, the mean wind speed for Uvwie local Government Area (4.50 m/s) indicates that area is suitable for large wind generation (commercial use). Lastly, the obtained data was compared to the Battelle Wind Energy Classification Scheme and the results of the above mentioned study areas fell into the Class 1 Wind Resource Power Category, WPD ? 100 W/m2 and for wind speed ? 4.4 m/s. This indicates that the wind resource of the areas under study are suitable for domestic use.

Research on Matching Characteristics of Wind Turbine and Generator for Small H-shaped Vertical Axis Wind Turbine

Based on the small H-shaped vertical axis wind wheel model (NACA0016),a CFD wind wheel model was constructed. Based on the principle of movinggrid, the grid division of the CFD wind wheel model is completed by usingGAMBIT software, and the boundary conditions such as the inlet boundaryand the outlet boundary are set reasonably. Then, the turbulence model andthe couple algorithm are used to carry out transient simulation calculations,and finally the aerodynamic parameter curves of the two-dimensional CFDwind wheel model are obtained. Based on this, the matching characteristicsof the wind turbine and generator of the small H-shaped vertical axis windturbine are studied. The research results show as follows: when the incomingwind speeds change in range of (2 m/s, 12 m/s), and the power character-istic curve and torque characteristic curve of the generator wind wheel arerespectively overlap the best power curve and best torque of the generator,the matching characteristics of the small H-shaped vertical axis wind turbinerotor and generator are optimal, which provides reference for carrying outrelated research.

Connection System for Small and Medium-Size Wind Generators through the Integration in an MMC and NLC Modulation

This paper presents a new way of organizing a wind farm with a large number of small to medium-sized turbines. Each wind generator has been included in a switching module of a modular multilevel converter (MMC), which generates the output voltage by near level control (NLC). The proposed topology reduces the number of semiconductors required, switching losses, and voltage filtering requirements. This topology replaces the usual configuration where each wind turbine is connected to a three-phase two-level back-to-back converter plus a filter and then connected in parallel with the other wind generators. To test the topology and its control performance, a case has been developed and simulated for generator configurations producing the same power, for generation imbalances between phases and for imbalances between arms. The analysis of the data shows that the converter works correctly and that it can deliver power to the grid in a balanced way even if the generation has imbalances. The generation imbalances between phases are compensated through the average value of the circulating current, while the imbalances between arms are compensated through the 50 Hz circulating current.

Modelling of Consumption Shares for Small Wind Energy Prosumers

This article describes a simulation of energy distribution in an average household where electricity is produced with a small wind generator or purchased from the public electricity grid. Numerical experiments conducted within an average of five minutes were performed using annual production and consumption graphs. Virtual storage devices, a water tank and a battery were used to buffer energy inside the household. The energy required for non-shiftable consumption and hot water consumption were taken directly from the utility grid. Surplus energy remaining from wind generator production after providing for consumption and storage needs were redirected there. A cover factor was used as a measure of the efficiency of energy distribution. One of the aims of the article was to determine by simulations the change of the cover factor in a virtually designed situation where the expected energy output of the wind generator was known in advance over one to three hours. The results found that for the configuration of the proposed nanogrid option, the positive results were readily achieved when the expected wind generator production was known an hour ahead. Then, the cover factor increased from 0.593 to 0.645. The side result of using projected/expected production is an increase in asymmetrical energy exchanges bilaterally between nanogrid and utility grid in favour of grid sales. Another finding was that the cover factor depended on the wind generator’s production intensity but less on the intensity of consumption within the household.It is hoped/expected that future research will address the prediction of output using mathematical methods.

An Energy Sharing Mechanism Achieving the Same Flexibility as Centralized Dispatch

Deploying distributed renewable energy at the demand side is an important measure to implement a sustainable society. However, the massive small solar and wind generation units are beyond the control of a central operator. To encourage users to participate in energy management and reduce the dependence on dispatchable resources, a peer-to-peer energy sharing scheme is proposed which releases the flexibility at the demand side. Every user makes decision individually considering only local constraints; the microgrid operator announces the sharing prices subjective to the coupling constraints without knowing users' local constraints. This can help protect privacy. We prove that the proposed mechanism can achieve the same disutility and flexibility as centralized dispatch, and develop an effective modified best-response based algorithm for reaching the market equilibrium. The concept of “absorbable region” is presented to measure the operating flexibility under the proposed energy sharing mechanism. A linear programming based polyhedral projection algorithm is developed to compute that region. Case studies validate the theoretical results and show that the proposed method is scalable.

Examining the Operation Method of a Small Wind Generator System Using Storage batteries

Examining the Operation Method of a Small Wind Generator System Using Storage batteries

Assessment of the energy efficiency of a hybrid wind-photovoltaic system for Cascavel, PR

The present work was developed at the Assis Gurgaz School of Engineering (FAG) and aimed to determine the efficiency of a wind-photovoltaic hybrid system for electricity generation. Three 140 W photovoltaic panels were installed to assess the generation of photovoltaic energy and the efficiency of its participation in the hybrid system. A small wind generator of 2000 W was used to evaluate the production of local wind energy, establishing the wind contribution in the hybrid system. Energy consumption was achieved with the installation of four 60 W incandescent lamps. The measurements of the meteorological quantities were obtained with the installation of a Micrometeorological station and the electrical data, with the use of a datalogger. Four batteries of 100 Ah each were installed to store the surplus electricity production and feed the installed load, when the system production was insufficient. A voltage divider, a rectifying bridge and an electronic device were installed to make it possible to record the quantities in the datalogger. The system showed efficiency of 12.5% for the generation of energy by the photovoltaic solar source, 18.7% for the wind generation and 11.9% for the entire hybrid system. The participation of the photovoltaic matrix contributed with 75.2% of all energy generated, while the wind matrix presented a contribution of 24.8%.

From Megawatts to Kilowatts: A Review of Small Wind Turbine Applications, Lessons From The US to Brazil

Increased use of fossil fuels has contributed to global warming due to greenhouse gas emissions, which has led countries to implement policies that favor the gradual replacement of their use with renewable energy sources. Wind expansion in Brazil is a success story, but its adherence to distributed generation is still a big challenge. In this context, the authors of this paper argue that the development of robust and viable distributed power grids will also depend in the future on improving small wind generation as an important alternative to the diversity of decentralized power grids. In this study, the authors present an overview of the small-sized Aeolic (or wind) energy market in Brazil, with the objective to support the debate regarding its expansion. Promoting the small wind market in Brazil is still a big challenge, but lessons can be learned from the United States. In this context, the article uses the United States learning curve, analyzing barriers that were found, as well as public policies implemented to overcome them. The lessons learned in the American market may guide public policies aimed at fostering this technology in Brazil. If technological improvements, certification and introduction of financial incentives were implemented in Brazil, the small wind industry chain could grow substantially, building a trajectory to promote the low carbon economy.

Modeling of an efficient high power wind energy conversion system using self-excited multi-phase machines

Self-Excited Multi-phase Induction Generators (SEMPIG) producing power from wind turbines infar-flung fields are receiving the interest of recent researchers. Small and medium energy wind generators involve 3-phase induction generators. SEMPIG with significant reliability, better fault tolerance, reduced harmonics, and high power-handling capability using reduced current per phase and maintaining the same per phase voltage makes it the promising contender in high-power WECS. This investigation analyzes the proficiency of energy efficient stand-alone self-excited seven-phase induction generator (SE7PIG) in wind energy schemes. This paper develops a cogent model from the two-phase equivalent circuit of SE7PIG using Matlab/Simulink. The study examines the modeling aspects of the SE7PIG with incorporated significant 7-rectifier and 7-phase inverter. The machine operational parameters speed, torque, voltage and current are presented. The 2MW WECS with 7-phase induction generator is analyzed with and without DC link converter. The results are compared with the 3-phase counterpart to illustrate the efficacy of SE7PIG for megawatt wind-power generation. The paper confirms the competence of SE7PIG with better fault tolerance and significant energy output with a decrease in phase current.

STUDY OF THE ELECTRICAL CHARACTERISTICS OF THE WIND GENERATOR FOR DISTRIBUTED GENERATION / ESTUDO DAS CARACTERÍSTICAS ELÉTRICAS DO GERADOR EÓLICO PARA GERAÇÃO DISTRIBUÍDA

This work aims to raise and evaluate technical parameters of commercial generators for use in small wind generation, aiming to obtain their electrical characteristics and performance. The method used will consist of simulating, in the workbench, starting and steady state operations, evaluating its response in the electric power quality generated by these equipment. This work is justified both by the need to seek compliance and technical improvement of the current electric machines used, as well as by reasons of public policies of incentives that promote distributed generation in the country. The preliminary results obtained quantify the electrical energy delivered to the point of connection by the turbine, evaluating the quality of the generated energy, enabling its improvement.

Hybrid based Small Wind Generator with Boost Converter System

Hybrid based Small Wind Generator with Boost Converter System

DWT-PSD extraction feature for defects diagnosis of small wind generator

1. Pons Llinares J, Climente Alarcón V, Vedreño Santos F, Antonino Daviu J, RieraGuasp M. Electric machines diagnosis techniques via transient current analysis. Proceedings of the 38th Annual Conference of the IEEE Industrial Electronics Society, IECON 2012, 25-28 October, Montreal, Canada. Google Scholar

Small wind generation using complex airfoil turbine

Near-ground wind is not stable and turbulent due to the ground effect and heat ventilation. Small wind generation system design for public utilities needs to catch the small wind to rotate the turb...