scholarly journals Small Wind Turbine Emulator Based on Lambda-Cp Curves Obtained under Real Operating Conditions

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2456
Author(s):  
Camilo I. Martínez-Márquez ◽  
Jackson D. Twizere-Bakunda ◽  
David Lundback-Mompó ◽  
Salvador Orts-Grau ◽  
Francisco J. Gimeno-Sales ◽  
...  
Keyword(s):  
Power Control ◽  
Wind Turbine ◽  
Low Cost ◽  
Operating Conditions ◽  
Control Algorithms ◽  
Graphic User Interface ◽  
Small Wind Turbine ◽  
Power Electronics Converters ◽  
Control Curves

This paper proposes a new on-site technique for the experimental characterization of small wind systems by emulating the behavior of a wind tunnel facility. Due to the high cost and complexity of these facilities, many manufacturers of small wind systems do not have a well knowledge of the characteristic λ - C p curve of their turbines. Therefore, power electronics converters connected to the wind generator are usually programmed with speed/power control curves that do not optimize the power generation. The characteristic λ - C p curves obtained through the proposed method will help manufacturers to obtain optimized speed/power control curves. In addition, a low cost small wind emulator has been designed. Programmed with the experimental λ - C p curve, it can validate, improve, and develop new control algorithms to maximize the energy generation. The emulator is completed with a new graphic user interface that monitors in real time both the value of the λ - C p coordinate and the operating point on the 3D working surface generated with the characteristic λ - C p curve obtained from the real small wind system. The proposed method has been applied to a small wind turbine commercial model. The experimental results demonstrate that the point of operation obtained with the emulator is always located on the 3D surface, at the same coordinates (rotor speed/wind speed/power) as the ones obtained experimentally, validating the designed emulator.

Mechanical characterization of materials for bulk forming using a drop weight testing machine

2010 ◽  
Vol 224 (9) ◽  
pp. 1795-1804 ◽  
Author(s):  
C M A Silva ◽  
P A R Rosa ◽  
P A F Martins
Keyword(s):  
Flow Stress ◽  
Mechanical Characterization ◽  
Low Cost ◽  
Testing Machine ◽  
Operating Conditions ◽  
Proportional Loading ◽  
Bulk Forming ◽  
Drop Weight ◽  
Characterization Of Materials

The main limitation of mechanical testing equipments is nowadays centred in the characterization of materials at medium loading rates. This is particularly important in bulk forming because strain rate can easily reach values within the aforesaid range. The aim of this article is twofold: (a) to present the development of a low-cost, flexible drop weight testing equipment that can easily and effectively replicate the kinematic behaviour of presses and hammers and (b) to provide a new level of understanding about the mechanical characterization of materials for bulk forming at medium rates of loading. Special emphasis is placed on the adequacy of test operating conditions to the functional characteristics of the presses and hammers where bulk forming takes place and to its influence on the flow stress. This is needed because non-proportional loading paths during bulk forming are found to have significant influence on material response in terms of flow stress. The quality of the flow curves that were experimentally determined is evaluated through its implementation in a finite-element computer program and assessment is performed by means of axisymmetric upset compression with friction. Results show that mechanical characterization of materials under test operating conditions that are similar to real bulk forming conditions is capable of meeting the increasing demand of accurate and reliable flow stress data for the benefit of those who apply numerical modelling of process design in daily practice.

Methods engineering for designing a didactic low cost small wind turbine generator

CCCA12 ◽  
2012 ◽  
Author(s):  
Azahel Trevifio ◽  
Lourdes Y. Garcia ◽  
David Lara ◽  
Jose O. Coronado ◽  
Rabhi Abdelhamid
Keyword(s):  
Wind Turbine ◽  
Low Cost ◽  
Turbine Generator ◽  
Wind Turbine Generator ◽  
Small Wind Turbine

scholarly journals Catchment Based Aerodynamic Performance Analysis of Small Wind Turbine Using a Single Blade Concept for a Low Cost of Energy

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5838
Author(s):  
Hailay Kiros Kelele ◽  
Torbjørn Kirstian Nielsen ◽  
Lars Froyd ◽  
Mulu Bayray Kahsay
Keyword(s):  
Wind Turbine ◽  
Energy Production ◽  
Low Cost ◽  
Aerodynamic Performance ◽  
Power Coefficient ◽  
Design Parameters ◽  
Wind Condition ◽  
Small Wind Turbine ◽  
Cost Of Energy ◽  
Wind Potential

For low and medium wind conditions, there is a possibility to harness maximum wind potential reducing the cost of energy by employing catchment-based wind turbine designs. This paper aims to study catchment-based small wind turbine aerodynamic performance for improved efficiency and reduced cost of energy. Hence, design parameters are considered based on specific conditions within a catchment area. The bins and statistical methods implemented with Weibull distribution of wind data for selected sites to characterize the wind conditions and a weighted average method proposed to create representative wind conditions implementing a single blade concept. The blade element method was applied using Matlab code (version R2017a, MathWorks Inc., Natick, MA, US) for aerodynamic design and analysis, and computational fluid dynamics employed using ANSYS—Fluent (version 18.1, ANSYS Inc., Canonsburg, PA, USA) for validation. The performance of the designed blade is evaluated based on annual energy production, capacity factor and power coefficient. Then, for site-specific wind conditions, yearly energy production, and relative cost of energy are examined against rated power. Appropriate rated power for a low cost of energy identified and performance measures evaluated for each site. As a result, a maximum power coefficient of around 51.8% achieved at a design wind speed of 10 m/s, and higher capacity factors of 28% and 50.9% respectively attained for the low and high wind conditions at the proposed rated powers. Therefore, for different wind condition sites, enhanced performance at a low cost of energy could be achieved using a single blade concept at properly selected rated powers employing suitable design conditions and procedures.

Design and Implementation of Low-Cost Safety system for Small Wind Turbine

2020 ◽  
Author(s):  
Pawel Rogowski ◽  
Malgorzata Prociow ◽  
Marcin Miller ◽  
Michal Kulak ◽  
Michal Lipian ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Low Cost ◽  
Safety System ◽  
Design And Implementation ◽  
Small Wind Turbine

Micro/small wind turbine power control for electrolysis applications

2016 ◽  
Vol 87 ◽  
pp. 182-192 ◽  
Author(s):  
Christopher Dixon ◽  
Steve Reynolds ◽  
David Rodley
Keyword(s):  
Power Control ◽  
Wind Turbine ◽  
Small Wind Turbine

scholarly journals Fluid–Structure Interaction Numerical Analysis of a Small, Urban Wind Turbine Blade

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1832 ◽  
Author(s):  
Michal Lipian ◽  
Pawel Czapski ◽  
Damian Obidowski
Keyword(s):  
Wind Turbine ◽  
Structural Strength ◽  
Fluid Structure Interaction ◽  
Point Of View ◽  
Operating Conditions ◽  
Strength Analysis ◽  
Fluid Structure ◽  
Rotor Aerodynamics ◽  
Structure Interaction ◽  
Small Wind Turbine

While the vast majority of the wind energy market is dominated by megawatt-size wind turbines, the increasing importance of distributed electricity generation gives way to small, personal-size installations. Due to their situation at relatively low heights and above-ground levels, they are forced to operate in a low energy-density environment, hence the important role of rotor optimization and flow studies. In addition, the small wind turbine operation close to human habitats emphasizes the need to ensure the maximum reliability of the system. The present article summarizes a case study of a small wind turbine (rated power 350 W @ 8.4 m/s) from the point of view of aerodynamic performance (efficiency, flow around blades). The structural strength analysis of the blades milled for the prototype was performed in the form of a one-way Fluid–Structure Interaction (FSI). Blade deformations and stresses were examined, showing that only minor deformations may be expected, with no significant influence on rotor aerodynamics. The study of an unorthodox material (PA66 MO polyamide) and application of FSI to examine both structural strength and blade deformation under different operating conditions are an approach rarely employed in small wind turbine design.

Thermodynamic Evaluation of a Small Wind Turbine

2014 ◽  
Author(s):  
Mohamed Gadalla ◽  
Sayem Zafar ◽  
Saad Ahmed
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Operating Conditions ◽  
Thermodynamic Evaluation ◽  
Ambient Conditions ◽  
Wind Speeds ◽  
Small Wind Turbine ◽  
Wide Range ◽  
Mechanical Power Output ◽  
Energy And Exergy

A small personal use wind turbine (PWT) is studied and tested for power, exergy and energy evaluation under different operating conditions. The wind turbine incorporates non-twisted blades of 1.5 m span and 0.27 m chord, using NACA 63418 airfoil. Using the earlier test results at pitch angles of 22°, 34° and 38° between the wind speeds of 4 m/s to 7 m/s, torque produced by each blade is determined. It is desired to calculate the torque as it is difficult to measure it for a small wind turbine. Using the governing equations and available computational fluid dynamics software, the total torque on each blade is determined. The resultant torque yielded the mechanical power output of the PWT. Using the available power, energy and exergy in the air flow, corresponding efficiencies are determined. To determine the changes in energy and exergy with respect to the wind speed, wind-chill factor expression is utilized. Results are collected for a wide range of wind speeds and pitch angles. Power, energy, exergy and their corresponding efficiency is evaluated to determine the optimal use pitch angle and ambient conditions. The pitch angles of 22° and 38o yielded high efficiencies although 22° produced the higher rotational speed as compared to 38°. The result suggests better performance for continuous wind speed conditions at low pitch angles — with respect to the rotating plane. For non-continuous wind conditions, higher pitch angles appeared beneficial.

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