Search results for "Wind"
showing 10 items of 846 documents
The formation of feed-in tariffs and the emergence of wind power in Finnish routine corporatism: favoring the economics of large-scale energy product…
2021
We explore the role and influence of the Finnish energy elite’s inner circle in the process of transition to renewable energy. Finland is a corporatist country where economic interest groups have p...
Buckling strength of steel tube for lifting telescopic wind steel tower
2021
Abstract A telescopic pole for wind energy production with low environmental impact and its lifting system for a 60–250 kW turbine and a height of 30 m have been designed and manufactured. The tower, was raised and lowered by automation or by remote control, that allows one to differentiate the presence of the generator within the landscape over time. The jacking systems acting on the legs had a combination of holes (on the legs) and pegs actuated by hydraulic pistons. The aim of the paper was the experimental and the analytical verification of the stability condition of the steel piston as a lifting system of the prototype. An experimental investigation was carried out on small-scale speci…
Active heave compensation of floating wind turbine installation using a catamaran construction vessel
2021
Abstract The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the installation efficiency of the floating offshore wind turbine, a novel concept is proposed by the SFI MOVE project. Several wind turbine superstructure components are preassembled onshore and carried to the installation site by a catamaran construction vessel. Each assembly can then be installed using only one lift, and the concept is less sensitive to weather conditions. In this paper, a control algorithm of the proposed hydraulic active heave compensator system i…
Hybrid Energy System for Rural Electrification in Sri Lanka: Design Study
2015
Off-grid hybrid renewable energy based power system for rural electrification has become an attractive solution for areas where grid electricity is not feasible. Depending on the availability of the resources, single energy source or a combination of several sources, including an energy storage system is used in an off-grid hybrid energy system. As there can be several candidates, the optimum sizing of the components against resource potential, cost and reliability is a vital issue. This chapter presents a study of optimum sizing of a renewable sources based off-grid hybrid energy system that is designed for electrifying a rural community in the Siyambalanduwa area in Sri Lanka. The communi…
Diagnostics of stator winding failures in wind turbine pitch motors using Vold-Kalman filter
2019
Pitch systems are among the most failure-prone components in wind turbines. Winding failures in pitch motors are common due to high start-up loads and poor ventilation. This article presents a diagnostics scheme that can detect the stator winding failures in the pitch motors under time-varying speed and load conditions. The proposed approach based on three-phase motor currents can be directly integrated into the motor drive and can be used for induction as well as permanent magnet synchronous machines. The extended Park's vector calculated on the motor currents is order tracked based on the supply frequency from the drive using Vold-Kalman filter. The approach is shown to be robust under ar…
Optimizing the generation system in a microgrid with power, thermal energy and mobility demands
2021
Microgrids are widely known to be the future of generation and distribution systems. This paper presents a method to optimize the size of the main components in a microgrid to supply the demands for electricity, heating and hydrogen for mobility through an Energy Hub model. The electricity production from a wind turbine, a CHP and a fuel cell satisfies the local electricity demand. The green hydrogen produced in the hub from renewable power in off-peak hours is used to feed the fuel cell or to meet the mobility demand. The heating power from CHP and fuel cell is used to feed the local district heating network.
Wind Shear On-Line Identification for Unmanned Aerial Systems
2014
An algorithm to perform the on line identification of the wind shear components suitable for the UAS characteristics has been implemented. The mathematical model of aircraft and wind shear in the augmented state space has been built without any restrictive assumption on the dynamic of wind shear. Due to the severe accelerations on the aircraft induced by the strong velocity variation typical of wind shear, the wind shear effects have been modeled as external forces and moments applied on the aircraft. The identification problem addressed in this work has been solved by using the Filter error method approach. An Extended Kalman Filter has been developed to propagate state. It has been tuned …
Joint probability distributions for wind speed and direction. A case study in Sicily
2015
In this study we analyze data of hourly average wind speed and direction measured at three different sampling stations located in Sicily (Italy) and provide a statistical model for their joint probability density function. Singly truncated from below Normal Weibull mixture distribution and a linear combination of von Mises distributions are used to model wind speed and direction. Sites with heterogeneous local conditions (prevailing wind direction and/or elevation) have been considered in order to investigate the reliability of the model here taken into consideration.
The passive cooling system from tradition to innovation: wind Towers
2012
The work presented by Golnaz Ighany, tutored by Maria Luisa Germanà, is a scheme that shows a synthesis of her PhD Research concluded in March 2011. The aim of the research was exploring the potential of using passive cooling systems and natural ventilation with special attention on wind towers. The study was focused on traditional passive cooling strategies which had been used in Middle East and Mediterranean areas. More particularly, the most common types of wind towers were analyzed in relation to different aspects: from the typology analysis to the dimensional one, from materials to systems and construction processes, from “live welfare” to energy efficiency. In parallel, it was conduct…
Comportamento di una passerella pedonale strallata nei confronti delle azioni del vento
2007
The wind behaviour of a stayed footbridge has been analyzed. In order to avoid aeroelastic phenomena, an experimental campaign on a 1:15 scale model has been realized at the boundary-layer wind-tunnel of the Milan Polytechnic. The aerodynamic characterization of the structure has allowed to direct the project towards the choice of non-solid barriers, but with a medium porosity, by avoiding possible problems that can lead to ultimate limit state condi-tions of the structure (e.g., flutter or vortex shedding). In this way the quantitative effect of barriers has been estimated deducing reliable values not only for the alongwind forces, but also for the crosswind and torsional actions.