Search results for "Speed"
showing 10 items of 876 documents
Enhanced LMMSE equalizer for high-speed single frequency network in HSDPA
2011
Currently, considerable interest has been shown in the research and standardization communities in multicell transmission schemes for HSPA, with a number of possible schemes under discussion that include Multiflow, Fast Cell Switching (FCS) and High-Speed Single Frequency Network (HS-SFN). In particular, HS-SFN is a promising technique that not only combines received energy from participating cells, but also reduces intercell interference with low UE complexity. In principle, HS-SFN can be implemented with a small modification to an LMMSE receiver at the UE. This paper introduces a more advanced LMMSE equalizer for High-Speed Single Frequency Network in HSDPA that achieves further performan…
Multi-step ahead wind speed forecasting using an improved wavelet neural network combining variational mode decomposition and phase space reconstruct…
2017
Abstract Accurate wind speed forecasting is crucial to reliable and secure power generation system. However, the intermittent and unstable nature of wind speed makes it very difficult to be predicted accurately. This paper proposes a novel hybrid model based on variational mode decomposition (VMD), phase space reconstruction (PSR) and wavelet neural network optimized by genetic algorithm (GAWNN) for multi-step ahead wind speed forecasting. In the proposed model, VMD is firstly applied to disassemble the original wind speed series into a number of components in order to improve the overall prediction accuracy. Then, the multi-step ahead forecasting for each component is conducted using GAWNN…
Generalized feed-forward based method for wind energy prediction
2013
Abstract Even though a number of new mathematical functions have been proposed for modeling wind speed probability density distributions, still the Weibull function continues to be the most commonly used model in the literature. Therefore, the parameters of this function are still widely used to obtain typical wind probability density distributions for finding the wind energy potential by researchers, engineers and designers. Once long-term average of Weibull function’s parameters are known, then the probability density distributions can easily be obtained. Artificial neural network (ANN) can be used as alternative to analytical approach as ANN offers advantages such as no required knowledg…
Active power maximizing for Wind Electrical Energy Generating Systems moved by a Modular Multiple Blade Fixed Pitch Wind Turbine
2008
This paper proposes a new solution for wind electrical energy generating system (WEEGS). The system here taken into account is moved by a modular multiple blade fixed pitch wind turbine (MMBFPWT) and foresees a new MPPT algorithm whose main characteristics are low cost, low noise, buildings simplicity and modularity. The mathematical model of the entire WEEGS has been here developed taking into account all the components starting from the wind turbine and ending with the electrical grid. The WEEGS mathematical model has been implemented in Matlab-Simulink in order to carry out the simulations needed to test the effectiveness of the proposed WEEGS. The simulations results show the effectiven…
Sliding-mode observer based sensor-less control of a small wind energy conversion system
2015
Small wind turbines are becoming an attractive solution for household applications. These micro generation units can be used as standalone applications or grid connected applications. However to get the full potential benefits of these wind turbines, systems should be low cost and reliable. Introducing the wind speed and rotor speed sensors at the generator shaft may reduce the reliability of small wind turbines. In this study, a grid connected sensor-less 5 kW small wind energy conversion system has been studied. The maximum power point tracking method of the wind turbine is totally independent from wind speed and rotor speed measurements. Optimum rotor speed and actual rotor speed are est…
Sensorless small wind turbine with a sliding-mode observer for water heating applications
2015
Water heating applications consume a considerable portion of electricity demand in most of countries. Small wind turbines are one of attractive alternatives for grid electricity based water heating systems. Wind energy can be converted to heat energy in a high efficient manner. However it is essential that wind turbine based water heating systems should be economical and reliable. Maximum power point tracking algorithm of most of available wind turbines requires information from a wind speed sensor and a rotor speed sensor which reduces the reliability of the system. In this paper, the proposed 5 kW wind turbine does not require external wind speed sensors and rotor speed sensors. The syste…
Application of Monte Carlo technique to evaluate the power injectable on electrical grid by wind farms
2008
This paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. To assess the maximum degree of wind generation penetrability in full compliance with the safe operation of the system, it seemed necessary to investigate the reports of contemporary winds and their territorial correlations when load assumes the peak or the minimum. Given the nature of the problem, it has been used a method of analysis based on the application of stochastic simulation techniques type Monte Carlo. In the paper, after describing the current state of wind energy generation in Sicily and development scen…
Pitch controller modeling for wind turbine power regulation using feed forward control strategies
2015
In this work, pitch controlled power regulation of a horizontal axis wind turbine coupled with a fixed speed asynchronous generator is studied using SimulationX®. Wind turbines need to be operated as per specified power output vs wind speed characteristics of it. If the wind speed is between the cut-in wind speed and the rated wind speed, then the wind turbine needs to be operated constant Cp. If wind speed is between the rated speed and the cut-off wind speed, then the wind turbine needs to be operated for constant rated power. To extract rated power above rated wind speed a proper controller strategy is required. This work provides a simulation model for power regulation of a horizontal a…
Computer Aided Optimization Via Simulation Tools of Energy Generation Systems With Universal Small Wind Turbines
2012
This paper considers the general issues in the project and the optimization of energy generation systems using small universal wind turbines, suitable in Distributed Generation (DG) and computer aided optimization for a better exploitation of wind source. Optimization in this field reveal to be more and more important because the local generation and consumption of electrical power, even for grid connected generators can suffers for unevenness of wind source exploitation, also in terms of wrong directions and in not regular wind flows. Computer aided design and optimization of small plants may give significant improvements in the development of the wind source also in accordance with the pr…
Impact of Building Layouts on Wind Turbine Power Output in the Built Environment: A Case Study of Tsu City
2014
In city planning, it is important to consider the future growth of renewable energy systems in the built environment. Wind speed analysis in the built environment is very important for analysing the wind turbine performance installed in the built environment. In this work, building topologies / layouts in Tsu city are considered for investing the wind speed distributions and directions. Wind speed profile in the built environment are developed by using CFD-ACE+. This work focusses on the analysis of the wind speed directions and distribution characteristics for finding out the proper location of the wind turbines in the built environment. The wind speed profiles and their directions and win…