Small-scale Wind Turbine Systems Research Articles

A Three-Phase Phase-Modular Single-Ended Primary-Inductance Converter Rectifier Operating in Discontinuous Conduction Mode for Small-Scale Wind Turbine Applications

Small-scale wind turbines play an important role in distributed generation since customers can use their houses, farms, and business to produce electric energy. The development of the power electronics system that processes the electric energy from small-scale wind turbines is a concern due to cost, simplicity, efficiency, and performance trade-offs. This paper presents the results of applying a three-phase phase-modular single-ended primary-inductance converter rectifier to processing the energy of a small-scale wind turbine system. The rectifier was designed according to the specifications of a commercial small-scale wind turbine system and tested in an emulator workbench, providing experimental data on the operation of the rectifier in this application. The rectifier can process the energy of a non-sinusoidal three-phase system since the permanent magnet synchronous generator has trapezoidal waveforms. The results show that the rectifier has the advantages of (i) using the inductance of the generator as the input filter inductor of the rectifier, (ii) providing input currents with the same shape as the voltages and in phase without the use of a current control system, (iii) simplicity of control of the DC output voltage and PWM modulation, and (iv) phase-modular characteristics that allow operating with phase fault without any additional control techniques. Due to the operation in discontinuous conduction mode, low efficiency in high power and/or low input voltage specifications are disadvantages.

Current source gate drivers for 3-phase VSI operated in small-scale wind turbine systems

The paper is dedicated to the improvement of efficiency of small-scale wind turbines’ (SSWT) power electronic converters. An efficiency of the 3-phase voltage source inverter that operates with low output voltage (<60 V) and high grid-side input voltage (380 V) is investigated. Such a solution allows skipping the intermediate DC/DC boost converter and thus reducing conversion losses and complexity of a system. The inverter has to oaperate with low duty cycles, which, in turn, demands increasing of switching speed and thus requires application of advanced transistors. To evaluate the switching performance, studies were carried out with various types of switches, namely Si IGBT, Si MOSFET, Cascode SiC JFET, SiC MOSFET using classic gate drivers and proposed current source drivers. Detailed switching waveforms were obtained using the double pulse method and analyzed for each type of the switch. The switching speed was assessed and losses were evaluated. Two types of transistors were selected for testing in the VSI paired with an EMRAX 228 generator. Inverter efficiency data was obtained and analyzed for two types of transistors/drivers and the speed-torque curve applicable for a 3 kW turbine. It is shown that the suggested solution improves the efficiency of SSWTs’ inverters.

Parametric Study of Eddy Current Brakes for Small-Scale Household Wind Turbine Systems

The design and application of eddy current brakes (ECBs) should be simple; further, ECBs should be used semi-permanently. This study aimed to determine major parameters for designing an ECB that can be applied to a small-scale wind turbine generator. To this end, an ECB was developed that could actuate without additional power, thus improving the efficiency of the generator. A series of simulations were conducted for a parametric study to pre-design ECBs suitable for small wind turbines. The six parameters chosen were disk thickness, number of magnets, radial location of magnets from center of disk, magnet pole arrangement, magnetic flux density, and rotational speed. The simulations were conducted on COMSOL Multiphysics. The results indicated that the number of magnets and magnet pole arrangements can significantly affect the performance curve of ECBs. Moreover, the disk thickness and rotational speed are linearly proportional to the braking torque.

Simulation of Glass Fiber Reinforced Polypropylene Nanocomposites for Small Wind Turbine Blades

This study aims to evaluate the effect of functionalized multi-walled carbon nanotubes (MWCNTs) on the performance of glass fiber (GF)-reinforced polypropylene (PP) for wind turbine blades. Support for theoretical blade movement of horizontal axis wind turbines (HAWTs), simulation, and analysis were performed with the Ansys computer package to gain insight into the durability of polypropylene-chopped E-glass for application in turbine blades under aerodynamic, gravitational, and centrifugal loads. Typically, polymer nanocomposites are used for small-scale wind turbine systems, such as for residential applications. Mechanical and physical properties of material composites including tensile and melt flow indices were determined. Surface morphology of polypropylene-chopped E-glass fiber and functionalized MWCNTs nanocomposites showed good distribution of dispersed phase. The effect of fiber loading on the mechanical properties of the PP nanocomposites was investigated in order to obtain the optimum composite composition and processing conditions for manufacturing wind turbine blades. The results show that adding MWCNTs to glass fiber-reinforced PP composites has a substantial influence on deflection reduction and adding them to chopped-polypropylene E-glass has a significant effect on reducing the bias estimated by finite element analysis.

Maximum Power Point Tracking Techniques for Micro-Grid Hybrid Wind and Solar Energy Systems - a Review

The rapid increase of population and city expansion has led to increased demand for electric power, which may tax conventional sources of electricity beyond their limits. Conventional electricity generation is also a source of environmental pollution and greenhouse gas emissions. To overcome these problems and to reduce generation costs, there is a need to employ and integrate economical and clean renewable energy sources. These power sources are mainly solar and wind energy through implementation of micro-grids. This paper presents a survey of how to develop hybrid renewable energy sources, in this case, PV solar systems and small scale wind turbine systems, to convert solar and wind energy into electricity. The survey explains the required equipment for power conditioning and maximum power tracking techniques (MPPT). It also discusses various kinds of DC/DC converters and their operating principles. This survey also deals with MPPT algorithms and techniques including Perturb and Observe, Incremental Conductance, Ripple Correlation Control, Fuzzy Logic, Neural Networks, ANFIS, Neuro-Fuzzy algorithms, and Parasitic Capacitance and comparison is made among them. The overarching goal is to mitigate atmospheric changes and extract the maximum power and voltage while maintaining power system stability. Copyright © 2020 Praise Worthy Prize - All rights reserved.

The maximum power point tracking based-control system for small-scale wind turbine using fuzzy logic

This paper presents the research on small-scale wind turbine systems based on the Maximum Power Point Tracking (MPPT) algorithm. Then propose a new structure of a small-scale wind turbine system to simplify the structure of the system, making the system highly practical. This paper also presented an MPPT-Fuzzy controller design and proposed a control system using the wind speed sensor for small-scale wind turbines. Systems are simulated using Matlab/Simulink software to evaluate the feasibility of the proposed controller. As a result, the system with the MPPT-Fuzzy controller has much better quality than the traditional control system.

The fuzzy-PID based-pitch angle controller for small-scale wind turbine

&lt;p&gt;This paper aims to design the pitch angle control based on proportional–integral–derivative (PID) controller combined with fuzzy logic for small-scale wind turbine systems. In this control system, the pitch angle is controlled by the PID controller with their parameter is tuned by the fuzzy logic controller. This control system can compensate for the nonlinear characteristic of the pitch angle and wind speed. A comparison between the fuzzy-PID-controller with the conventional PID controller is carried out. The effectiveness of the method is determined by the simulation results of a small wind turbine using a permanent magnet generator (PMSG).&lt;/p&gt;

Performance Improvement for Small-Scale Wind Turbine System Based on Maximum Power Point Tracking Control

This paper proposes a strategy for performance improvement of small-scale wind turbine systems using maximum power point tracking control (MPPT). In this study, wind-turbine systems which use permanent magnet synchronous generators and converter devices are modeled in Simulink-Matlab software. In order to increase the power generated, MPPT is used based on the extended perturb and observe (PO) method. This algorithm has the ability to improve the speed of the turbine without oscillation. To analyze the ability of the PO-based MPPT in maximizing output power, performance examination of wind turbine systems in Simulink-Matlab software was conducted. The study is carried out with a 3000 W wind turbine device serving various electrical loads of 50 Ω, 100 Ω, 200 Ω, and 300 Ω, and each ohm varies with a wind speed of 4, 5, 6.5, 7, 8.5, 9, and 10 m/s. The overall turbine system performance found that the maximum increase in system output power occurs when it is loaded with 200 Ω with a wind speed of 6.5 m/s. During this combination of 200 Ω and 6.5 m/s, there are high increments of output power at 135.62% caused by the installation of MPPT controllers, with an average output power increase of 50.77%. The results of this study proved that PO-based MPPT has successfully improved the performance of wind-turbine systems.

A case study: Small scale wind turbine system selection and economic viability

Increasing electricity production costs coupled with rising energy prices drive people to become energy independent. Wind energy systems can be one of the most cost-effective home-based renewable energy systems. A small-scale wind turbine can reduce the electricity bill slightly or up to 100% depending on the quality of wind resource of the site. More people across the world are seeking a solution against increasing electricity rates and a way to harvest their local wind resources. The aim of the study is to analyse an economic viability of a small-scale wind turbine system for residential use in southern Turkey. For this objective, firstly, an actual onsite wind data is evaluated. Five different on-grid small-scale wind energy production system alternatives which required to meet the electricity demand are offered. Performance of each turbine are examined; cost and benefit analysis based on cash flow, net present value, levelised cost of energy and payback periods are calculated. Recommendations are provided to the investor to make a decision on the optimum wind turbine selection based on performance and economic viability for the given site. At last, an overview of what is feasible on the preferred site is presented.

Feasibility Study of Embedded Wind Energy Harvesting System for Parafoil-Payload Aircraft

A logistics issue for guided air-drop systems is maintaining batteries inside the airborne guidance unit so that when the system is deployed the batteries are adequately charged to power onboard electronics and actuators. It is typical for a guided air-drop system to be packed and readied for use well before deployment, leading to nonnegligible battery self-discharge. This necessitates a process to both monitor battery life and recharge the systems after a certain time interval. This paper explores, using a small-scale wind turbine system, providing the requisite power for onboard electronics and actuation for a guided air-drop system. Sizing studies are reported to estimate the necessary size of the rotor and generator. Using this information, a full-scale airborne guidance unit was designed, fabricated, and tested in a wind tunnel. Results indicate that a 0.33 m diam turbine system can generate over 3.7 W of continuous power, which is sufficient to provide power to low-power consumption guided air-drop systems, such as a bleed-air actuated system.

Design and Evaluation of Glass/epoxy Composite Blade and Composite Tower Applied to Wind Turbine

In the study, the analysis and manufacturing of small class wind turbine blade was performed. In the structural design, firstly the loading conditions are defined through the load case analysis. The proposed structural configuration of blade has a sandwich type composite structure with the E-glass/Epoxy face sheets and the Urethane foam core for lightness, structural stability, low manufacturing cost and easy manufacturing process. And also, this work proposes a design procedure and results of tower for the small scale wind turbine systems. Structural analysis of blade including load cases, stress, deformation, buckling, vibration and fatigue life was performed using the finite element method, the load spectrum analysis and the Miner rule. Moreover, investigation on structural safety of tower was verified through structural analysis by FEM. The manufacturing of blade and tower was performed based on structural design. In order to investigate the designed structure, the structural tests were conducted and its results were compared with the calculated results. It is confirmed that the final proposed blade and tower meet the design requirements.

Energy Management of A Small-Scale Wind Turbine System Combined with Battery Storage System

Energy Management of A Small-Scale Wind Turbine System Combined with Battery Storage System

Technical and economic analysis of home energy management system incorporating small-scale wind turbine and battery energy storage system

Home energy management system (HEMS) is an important problem that has been attracting significant attentions in the recent years. However, the conventional HEMS includes several shortcomings. The conventional HEMSs mainly utilize battery energy storage system (BESS) to deal with energy uncertainties. But they only ascertain optimal charging-discharging pattern for BESS and the power and capacity of BESS are not optimally determined. Furthermore, most of the HEMSs are modeled as a mixed integer linear programming (MILP) including linearization and relaxations. Additionally, considering all possible operating conditions for home has not been adequately addressed in the existing HEMSs. The possible operating conditions are (i) receiving energy from the main grid (i.e., purchasing energy), (ii) sending energy to the utility grid (i.e., selling energy), (iii) working on standalone mode as disconnected from the network (i.e., net-zero energy building). As a result, current paper deals with these existing challenges at the same time. This paper presents HEMS including small-scale wind turbine, BESS, load curtailment option, and fuel cell vehicle. The introduced HEMS not only determines optimal charging-discharging pattern for BESS, but also specifies optimal capacity and optimal rated power of the BESS at the same time. The proposed HEMS is expressed as a mixed integer nonlinear programming (MINLP) and solved by cultural algorithm as an effective Meta-heuristic optimization algorithm. All three operating conditions are considered for home. Output power of wind unit is modeled by Gaussian probability distribution function (PDF) and Monte-Carlo simulation (MCS) is applied to deal with uncertainties. Results emphasize on the feasibility and usefulness of the introduced HEMS.

Modeling and Experimental Study of a Wind Turbine System in Hybrid Connection With Compressed Air Energy Storage

This paper presents a new hybrid wind turbine system that is formed by a continuously variable transmission connection of the turbine drive shaft with an air expander/compressor. A mechanical power split device is designed to synthesize the power delivered by the wind turbine and the air expander/compressor. A small-scale hybrid wind turbine system is mathematically modeled, analyzed, and validated using a laboratory-scale experimental test rig. By utilizing compressed air energy storage, it is shown that the hybrid wind turbine system can provide smooth power output under fluctuating wind speed conditions. Such a direct connection structure reduces the overall system cost by using one generator instead of two compared with the conventional CAES system structure. The study demonstrates the benefit of improved efficiency and flexibility brought to the turbine operation by the hybridization of wind energy and stored energy.

Development of a high-efficiency and long-life 500W class H-Darrieus-type vertical axis wind turbine (VAWT) system using skin-spar-foam sandwich composite structure

Abstract Since the focus on the energy crisis and environmental issues due to excessive fossil fuel consumption, wind power has been considered as an important renewable energy source. Recently, several megawatt-class large-scale wind turbine systems have been developed in some countries. Even though the large-scale wind turbine can effectively produce electrical power, the small-scale wind turbine has been continuously developed due to some advantages; for instance, it can be easily built at a low cost without any limitation of location, i.e., even in the city. In case of small-scale wind turbines, the vertical axis wind turbine (VAWT) is used in the city despite having a lower efficiency than the horizontal axis wind turbine. Furthermore, most small-scale wind turbine systems have been designed at the rated wind speed of around 12 m/s. This aim of this work is to design a high-efficiency 500W class composite VAWT blade that is applicable to relatively low-speed regions. With regard to the aerodynamic design of the blade, parametric studies are carried out to decide an optimal aerodynamic configuration. The aerodynamic efficiency and performance of the designed VAWT is confirmed by computational fluid dynamics analysis. The structural design is performed by the load case study, initial sizing using the netting rule and the rule of mixture, structural analysis using finite element method (FEM), fatigue life estimation and structural test. The prototype blade is manufactured by hand lay-up and the matched die molding. The experimental structural test results are compared with the FEM analysis results. Finally, to evaluate the prototype VAWT including designed blades, the performance test is performed using a truck to simulate various ranges of wind speeds and some measuring equipment. According to the performance evaluation result, the estimated performance agrees well with the experimental test results in all operating ranges.

Gers gone wired: Lessons from the Renewable Energy and Rural Electricity Access Project (REAP) in Mongolia

This article explores the Renewable Energy and Rural Electricity Access Project (REAP) in Mongolia, an internationally sponsored $23 million program that delivered more than 40,000 solar home systems (SHS) and small-scale wind turbine systems (WTS) to nomadic herders. It begins by explaining its methods of data collection, consisting primarily of semi-structured research interviews and site visits. It then briefly describes the history and status of the electricity sector in Mongolia, as well as the current state of rural electrification and energy use among nomads and off-grid herders. Next, it explains the genesis of REAP, exploring its three primary components related to herder electrification, expansion of soum electricity services, and national capacity building. The following sections analyze the benefits derived from REAP as well as its lingering challenges. The final section concludes by noting that grid electrification efforts should continually be complemented with targeted policies and programs aimed at assisting herders, that rural energy programs work best when they ensure the participation of the private sector and also solicit feedback from consumers and end users, and that rural electricity services should be coupled with broader economic development efforts.