scholarly journals Design and simulation of an optimized small wind turbine

2021 ◽  
Author(s):  
◽  
Norberto Fernando Soares Sanjimba
Keyword(s):  
Control System ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cost Of Energy ◽  
Small Wind Turbines ◽  
The Cost ◽  
Large Wind

The volatility of fossil fuel's price, pollution, and emission associated with converting fos- sil fuel into a useful type of energy led man to search for more sustainable energy sources that are pollution-free and renewable. Today, renewable energy technologies, such as solar and large wind turbines, are developed to a stage of maturity, having the cost of produc- ing electricity dropping signi􏰀cantly in the last decade, therefore making these technologies competitive with the traditional counterpart. The cost of producing electricity through small wind turbines is still high compared to large wind turbines or photovoltaic technology. For small wind turbines to successfully compete with other technologies and contribute to the diversi􏰀cation of o􏰈-grid technology, further research is needed to reduce the levelised cost of energy (LCOE). Therefore, this study aims to reduce the levelised cost of energy (LCOE) of small wind turbines. To achieve the ob- jective, a 10 kW wind turbine operating at a site of an average wind speed of 7.5 m/s was designed, optimized, and simulated. With low LCOE in mind, the turbine components were designed as simple as possible to reduce manufacturing costs. The blades are made of uniform cross-sectional area, which made possible to use aluminum as the blade material, and the blade cross-sectional area is made out of a high lift airfoil. The hub is made of aluminum and modelled and designed as a disc with holes to bolt the blades and attach the main shaft. The mainframe is treated as a thick plate with a proper arrangement to connect the generator, the main and yaw bearings, the tail support, and any other ancillaries needed. An octal tapered tower with a height of 20 m made of steel was designed and optimized for low weight. The electrical power is to be produced by a direct drive variable speed permanent magnet synchronous generator. The control system is designed in such a way that allows the turbine to operate in maximum power e􏰊ciency for any speed below the rated speed, and to increase reliability, a sensorless control system is suggested. The research started with a broad review of the relevant literature on wind turbines in general and small wind turbines. The turbine blades design began by analysing the aero- dynamic performance of the blade. To accomplish that, XFoil was used to generate the aerodynamic parameters of the airfoil, the Blade Element Momentum (BEM) method was used to estimate the blades' aerodynamic performance, and Qblade was employed to com- pare the results, and Computational Fluid Dynamics (CFD) was used to verify the results. The preliminary design was done using standard IEC 61400-2 to obtain the load cases, and general engineering formulas, CFD and Finite Element Analysis (FEA) was used to analyse the load in the components according to IEC 61400-2, FAST-V7 was used to simulate the turbine's overall performance, standard formulas were used to evaluate the economic perfor- mance of the design, MatLab was used to perform all needed calculations. In this study, it is evident that using standard IEC 61400-2 to estimate the load, gyroscopic load components dominate the design, and the control system must be used to limit those loads. The designed turbine has relatively high e􏰊ciency and low LCOE.

Tailrace surge shaft optimization procedure for minimum downsurge

2018 ◽  
Vol 45 (6) ◽  
pp. 446-457
Author(s):  
Satyajeet Sinha
Keyword(s):  
Optimization Procedure ◽  
Water Velocity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Tailrace Tunnel ◽  
The Cross ◽  
The Cost ◽  
Low Pressures ◽  
The Relationship

Tailrace surge shafts are required in hydropower projects where the spent water is conveyed through a long tailrace tunnel under pressure to the recipient. Startup and shutdown of the turbine can cause sudden changes in water velocity and can develop dangerously high and low pressures. Surge shafts are provided in water conductor systems to significantly reduce these pressure surges. Based on numerous transient analyses carried out, it was observed that the cross-sectional area of the tailrace surge shaft can be optimized based on the relationship between the differences in the tailwater level and the minimum downsurge level at the tailrace surge shaft obtained with respect to the different lengths of the tailrace tunnel and different cross-sectional areas of the tailrace surge shaft. In this study, a procedure was proposed by which the tailrace surge shafts can be optimized and, hence, the cost of the hydropower projects with tailrace surge shafts can be minimized.

A Shape Annealing Approach to Optimal Truss Design With Dynamic Grouping of Members

1995 ◽  
Author(s):  
Kristina Shea ◽  
Jonathan Cagan ◽  
Steven J. Fenves
Keyword(s):  
Optimal Number ◽  
Cross Sectional Area ◽  
Topology Design ◽  
Sectional Area ◽  
Cross Sectional ◽  
Truss Topology Design ◽  
Optimal Truss Design ◽  
Optimal Grouping ◽  
The Cost ◽  
Number Of Classes

Abstract A shape annealing approach to truss topology design considering the tradeoff between the mass of a structure and multiple members of the same size, called a class of members, is presented. The problem of optimal grouping involves finding a structural design with an optimal number of classes and the optimal sizes of those classes; cross-sectional area is considered as the measure of size in this paper. Multiple members of a uniform cross-sectional area is advantageous when considering the cost of purchasing and fabricating materials to build a structure. The shape annealing method (Reddy and Cagan 1994) is used as an approach to solve this problem by incorporating a method for dynamic grouping of members into classes and adding a constraint for the number of allowable classes. This method is demonstrated on arch and truss problems. As well, results from an imposed symmetry constraint for the truss problem will be shown.

Development and Field Test Performance of a Non-Conventional Unidirectional Co-Axial Two Series Rotors Micro Wind Turbine

2013 ◽  
Vol 768 ◽  
pp. 119-123
Author(s):  
Sandip A. Kale ◽  
S.N. Sapali
Keyword(s):  
Wind Turbine ◽  
Field Test ◽  
Wind Turbines ◽  
Power Output ◽  
Test Performance ◽  
Rural Population ◽  
Direct Drive ◽  
Wake Effect ◽  
Small Wind Turbines ◽  
Large Wind

The technology of harnessing wind energy through traditional three-bladed large wind turbines is in mature state. There are many disputes about the performance and availability of power output of the small wind turbines. The small wind turbines need improvement in technology for low speed starting behavior, enhancement in coefficient in performance, assured power output in low wind region. This work consists of development and field test performance of a non-conventional unidirectional co-axial two series rotors micro wind turbine to supply electricity for rural population. The unidirectional co-axial series rotor wind turbine consists of small rotors to replace a big rotor, mounted on a tilted long driveshaft at appropriate distances to face fresh wind, coupled to a direct drive generator. The developed turbine consists of two rotors, placed at suitable interval to avoid the wake effect. This work also includes field test performance and its analysis.

scholarly journals An Energy Efficiency Estimation Procedure for Small Wind Turbines at Chosen Locations in Poland

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3706
Author(s):  
Justyna Zalewska ◽  
Krzysztof Damaziak ◽  
Jerzy Malachowski
Keyword(s):  
Energy Efficiency ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Estimation Procedure ◽  
Efficient Solutions ◽  
Energy Potential ◽  
Payback Time ◽  
Small Wind Turbines ◽  
Efficiency Estimation ◽  
The Cost

Contrary to the extensive amount of research on large wind turbines, substantial analyses of small wind turbines are still rare. In the present study, the wind energy potential of three locations in Poland is analyzed using real wind data from a five-year period and the parameters of the selected turbine model. Appropriate simulations are performed to assess the energy efficiency of the analyzed investments at a coastal, foothill, or lowland site. According to the results, the most favorable location for a small wind turbine is the coastal site (wind zone I). The payback time at this location is approximately 13 years, whereas the payback times at the other two analyzed are more than 3 times longer. The payback periods for the latter locations significantly exceed the estimated lifetime of the wind turbine, ruling out their economic viability. The cost of electricity generation varies greatly, from 0.16 EUR/kWh at the coastal location to 0.71 EUR/kWh at the lowland location. These results provide a reference for developing more efficient solutions, such as the use of a turbine with a shielded rotor, which can increase the power of the turbine by approximately 2.5 times.

scholarly journals Optimization of Thermal Backfill Configurations for Desired High-Voltage Power Cables Ampacity

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1452 ◽  
Author(s):  
Stanislaw Czapp ◽  
Filip Ratkowski
Keyword(s):  
High Voltage ◽  
Cross Sectional Area ◽  
Power Cable ◽  
Power Cables ◽  
Sectional Area ◽  
Cable System ◽  
Cross Sectional ◽  
The Core ◽  
The Cross ◽  
The Cost

The ampacity of high-voltage power cables depends, among others, on their core cross-sectional area as well as thermal resistivity of the thermal backfill surrounding the cables. The cross-sectional area of the power cables’ core is selected according to the expected power to be transferred via the cable system. Usually, the higher the power transfer required, the higher the cross-sectional area of the core. However, the cost of high-voltage power cables is relatively high and strictly depends on the dimensions of the core. Therefore, from the economic point of view, it is interesting to focus on the improvement of the thermal condition around the cables, by changing the dimension of the thermal backfill, instead of increasing the power cables’ core cross-sectional area. In practice, it is important to find the optimal dimensions of both cable core and thermal backfill to achieve the economically attractive solution of the power cable transfer system. This paper presents a mathematical approach to the power-cable system design, which enables selecting the cost-optimal cross-section of a power cable core depending on the dimensions of the thermal backfill. The proposal herein allows us to indicate the condition in which it is advantageous to increase the core cross-sectional area or to expand the dimension of the backfill. In this approach, the optimal backfill geometry can also be evaluated. The investment costs of the 110 kV power cable system with the core cross-sectional areas consecutively equal to 630, 800 and 1000 mm2 have been compared.

A Shape Annealing Approach to Optimal Truss Design With Dynamic Grouping of Members

1997 ◽  
Vol 119 (3) ◽  
pp. 388-394 ◽  
Author(s):  
K. Shea ◽  
J. Cagan ◽  
S. J. Fenves
Keyword(s):  
Optimal Number ◽  
Cross Sectional Area ◽  
Topology Design ◽  
Sectional Area ◽  
Transmission Tower ◽  
Cross Sectional ◽  
Truss Topology Design ◽  
Optimal Truss Design ◽  
Optimal Grouping ◽  
The Cost

A shape annealing approach to truss topology design is presented that considers the tradeoff between the mass of the structure and the grouping of members, where all members of a group are given the same size. The problem of optimal grouping involves finding a structural design with an optimal number of groups and the optimal sizes for each group. In this paper cross-sectional area is considered as the measure of group size. Designs incorporating multiple members with the same cross-sectional area are advantageous when considering the cost of purchasing and fabricating materials. The shape annealing method is used as an approach to solve this problem by incorporating a method for dynamic grouping of members based on cross-sectional area that creates a tradeoff between mass and the number of groups through a weighted objective function that includes a group penalty function. This method is demonstrated on transmission tower and general truss problems.

Rowing Force Simulation and Control System

2010 ◽  
Vol 164 ◽  
pp. 161-164 ◽  
Author(s):  
Vytautas Grigas ◽  
Alexandra Legha ◽  
Anatolijus Sulginas ◽  
Rymantas Tadas Toločka
Keyword(s):  
Control System ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Hydraulic Loading ◽  
Training Facility ◽  
Force Variation ◽  
Simulation And Control ◽  
The One ◽  
And Control

The rowing force simulation and control system is to be developed to generate the loading on the oar during the rowing stroke most adequate to the one acting during waterborne rowing. The paper presents the methodology of defining the law of change of loading on the oar by changing the cross-sectional area of flow channel of hydraulic loading unit at indoor rowing training facility. An example of the rowing force variation during one cycle obtained by using such a system is provided.

scholarly journals THE EFFICACY OF THE CABLES OF 6–110 KV WITH XLPE INSULATION. Part 1

2017 ◽  
Vol 60 (5) ◽  
pp. 417-432 ◽  
Author(s):  
M. A. Korotkevich ◽  
S. I. Podgaiskiy ◽  
A. V. Golomuzdov
Keyword(s):  
Cross Sectional Area ◽  
Operating Costs ◽  
Sectional Area ◽  
Cross Sectional ◽  
Reduced Costs ◽  
Cable Lines ◽  
The Cost ◽  
Paper Insulation ◽  
Xlpe Insulation

The assessment of the suitability of cables of 6–110 kV with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the criterion of reduced costs. Thus, the comparison was undertaken between cables of various design and material of insulation: three-core paper insulated ones vs. three-core XLPE insulated ones; three-core paper-insulated ones vs. solid wires with XLPE insulation; single-core oil-filled cables of 110 kV with paper insulation vs. solid wires of 110 kV with XLPE insulation. The increase in long-term permissible current loads for cables with XLPE insulation because of the larger permissible temperature of heating in comparison with cables with paper-oil insulation complies with as would increase in the cross-sectional area of cable cores (equal to 0.61 from the original) and therefore reduces the cost of the cable by reducing the cost of manufacture of conductors. The reduced costs of the construction and operation of cable lines with XLPE insulation (accounting the increase in the cost of a cable 1.2 and 2 times as compared with the cost of a cable with three-core insulation), despite the decline in the cost of manufacture of conductors and the reduced annual operating costs (9 % and 17 % respectively of cable lines of voltage of up to 35 kV and 110 kV), occurred to be more than the reduced costs of the construction and operation of cable lines with paper insulation. Currently the cost of one meter of cable with XLPE insulation is less than the cost of cables of AAB, CASB, AASv types of a voltage of 10 kV with aluminium cores, that ensures their undeniable efficacy.

Impacts of Reliability on Operational Performance and Cost of Energy Evaluation of Multi-Megawatt, Far-Offshore Wind Turbines

2019 ◽  
Author(s):  
Cuong D. Dao ◽  
Behzad Kazemtabrizi ◽  
Christopher J. Crabtree
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Economic Performance ◽  
Large Scale ◽  
Offshore Wind ◽  
Component Reliability ◽  
Offshore Wind Turbines ◽  
Cost Of Energy ◽  
The World ◽  
The Cost

Abstract Wind energy is growing at a fast pace around the world. According to a report published by WindEurope, 55% of total power capacity installations in the EU came from wind in 2017. In this context, offshore wind plays a decisive role, with countries such as the UK leading the development of large-scale offshore wind projects within Europe and around the world. It is essential that the cost of energy from offshore wind remains competitive with other sources of energy to encourage further investment in offshore wind developments. One way to maintain and further reduce the cost of offshore wind energy is to take advantage of economies of scale by increasing the megawatt ratings of offshore wind turbines. On the other hand, the operational expenditure of the turbines could also be reduced significantly. In this paper, we present a new integrated operation simulation framework for performance evaluation of multi-megawatt direct drive wind turbines suitable for use in far offshore wind farms. The operation simulation considers several essential wind turbine data such as component reliability, i.e. failure rates and downtimes per failure, historical wind speed, turbine information, and repair cost per failure to estimate the operational and economic performance of the wind turbine in its entire lifetime. In the proposed operation simulation, component reliability models and a wind power model are coupled together to simulate wind turbine operation over its entire lifetime using a time-sequential Monte Carlo simulation. Since the reliability data for large-scale offshore wind turbines are scarce and/or restricted to only direct stakeholders, a range of operational profiles for the turbines based on different level of reliability are simulated. In addition, the economic performance of the turbine is measured by defining an index for levelised cost of energy as a function of component reliability. In this way, the wind turbine reliability, power output, failure cost and levelised cost of energy are estimated under the variation of input reliability data. The results of this paper can inform wind turbine performance depending on the reliability of its components, and provide useful information for critical components identification and economic assessment of future far offshore wind turbines.

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