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The paper is dedicated to the study of aerodynamic effects in small power wind turbine rotors using mathematical models to describe the fluid flow physics and modern methods of numerical simulation in the framework of computational fluid dynamics (CFD). There was argued the geometry of blades' aerodynamic profiles efficient in terms of energy conversion efficiency and based on them original concepts...
The introduction and penetration of non-conventional renewable energy based generation technologies in South Africa and the world over has increased grid connection complexities. This has resulted in strict grid code requirements by utilities in order to ensure a reliable, safe and economically manageable grid operation. This justifies the need for adequate system models to represent overall system...
Wind turbine generators represent a valid and sustainable alternative for a significant energy provision, which is increasingly demanded by the planet, and a number of generator models have been proposed for supporting their design. However, equatorial regions have very special conditions for their gravity and wind behavior. Therefore, we present here a new wind turbine-generator model suitable for...
This paper aims to give an overview of the recent development and benefits of model predictive control in wind turbines and its future potential. For a modern large wind turbine, the main objective of control is to maximise the power production while maintaining the fatigue loads to be minimal. With such multiple objectives, a multivariable system and actuators constraints the popular PI controller...
In this study a wound rotor AC induction machine which can be used in wind turbine is modeled in LabVIEW program and the system model optimization is done with system identification (SI) method. Wind turbines are usually used as synchronous and asynchronous. In this study, to be safe and because of the advantages such as low costs, WRIM is preferred. In the control of the excitation circuit, SI method...
Power produced by a wind turbine is directly proportional to the cube of wind velocity. Small amount of increase in wind velocity significantly increases power output. Use of diffuser around the wind turbine causes pressure reduction behind the wind turbine and draws more air flow at increased velocity through the rotor. The length of the diffuser and associated problems are the barriers for field...
In wind farm operation, the performance and loads of downstream turbines are heavily influenced by the wake of the upstream turbines. Furthermore, the actual wake is more challenging due to the dynamic phenomenon of wake meandering, i.e. the turbine wake often demonstrates dynamic shift over time. To deal with the time-varying characteristics of wake meandering, the dual-mode linear quadratic model...
A Newton method based on a Numerical Differentiation (ND) process is applied to achieve the periodic steady-state solution of an induction machine in an efficient way. In order to increase the efficiency of the ND process, a parallel implementation of this method is applied. The efficiency of the proposed method is compared against the simulation time taken in achieve the solution of the induction...
Present work conducts computer simulations with the Computational Fluid Dynamics (CFD) software package Fluent as a modeling tool to explore aerodynamic characteristics of a newly designed wind turbine for electricity generation. The governing equations consisting of three-dimensional, time-dependent conservation of mass and momentum are solved. The k-ε turbulence model is adopted for the turbulent...
Many wind turbine designs employ induction machines, operating as fixed speed, squirrel cage generators, or as variable speed, wide slip and double fed induction generators (DFIG). In order to study, prototype, and demonstrate the effectiveness of each design, an electro-mechanical model of a wind turbine power train has been constructed at an approximate scale of 1:1000, relative to a utility-scale...
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