- Category: Articles
Expanding the Speed Range with the Doubly-Fed Induction Generator
Developments in power electronics, electrical drives and wind turbines have allowed an increase in the power of wind systems. The need to limit mechanical stress and power disturbances has led to strong demand for variable speed systems. In wind generation systems it is necessary to decouple and control active and reactive power flow with fast response because of mains requirements. Fast and accurate control is especially important when the induction machine is designed to operate below synchronism rotational speed as a generator. This article describes a controller that can extract power from wind kinetic energy over a large speed range, at both sub- and hyper-synchronism speeds.
By Paulo Costa, António Martins and Adriano Carvalho, Portugal
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By Paulo Costa, António Martins and Adriano Carvalho, Portugal
- Category: Articles
Development of a Methodology for Wind Resource Assessment
Since 1995, COPEL (the local utility of the State of Paraná, Brazil) has been developing, in partnership with LACTEC and CAMARGO SCHUBERT, research and development projects in the area of wind energy. In 1999, the project named ‘Projeto VENTAR’ introduced the ‘Wind energy resource map of the State of Paraná’. In line with the global growth of renewable energy utilisation, and the beginning of the Brazilian wind energy market, COPEL has developed a methodology to support feasibility analyses of wind farm projects in Brazil. The author gives a description of the methodology and results achieved.
By Luiz Procopiak, LACTEC, Brazil
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Since 1995, COPEL (the local utility of the State of Paraná, Brazil) has been developing, in partnership with LACTEC and CAMARGO SCHUBERT, research and development projects in the area of wind energy. In 1999, the project named ‘Projeto VENTAR’ introduced the ‘Wind energy resource map of the State of Paraná’. In line with the global growth of renewable energy utilisation, and the beginning of the Brazilian wind energy market, COPEL has developed a methodology to support feasibility analyses of wind farm projects in Brazil. The author gives a description of the methodology and results achieved.
By Luiz Procopiak, LACTEC, Brazil
- Category: Articles
Valuable Data for the Wind Power Industry
Research at the National Aeronautics and Space Administration’s (NASA’s) Earth Science Enterprise is complementing the development of offshore wind power in the USA. The American space agency is experimenting with a new technology to measure surface-level sea winds from orbit. Created for monitoring marine weather conditions in general, this technique could evolve into an operational system that would supply valuable data to the wind power industry. Not surprisingly, a high vantage point may offer the best view for offshore wind information.
By Avery Sen, Policy Analyst and ORISE Fellow, National Oceanic and Atmospheric Administration
- Category: Articles
Optimising Capacitors for Wind Power Applications
All wind turbines face a similar set of challenges. They need to extract power at low wind speeds and fluctuating wind profiles in order to maintain adequate yield. They also need to ensure adequate power quality to operate appliances or to feed into a grid. In addition, the electrical system must be constructed to minimise losses and thereby maintain high efficiency and reliability. In this article, the author, from Vishay Intertechnology, Inc, discusses how capacitors can be optimised to meet these challenges.
By Josef Reindl, Vishay ESTA, Theo van de Steeg and Frans van Roemburg, Vishay BCcomponents
- Category: Articles
A Commentary on the Issues Facing Wind Park Developers in the UK
The UK offshore wind energy sector is booming at the moment. This is largely because of the UK government’s ‘Renewables Obligation’ targets for the generation of electricity from renewable sources of 10% by 2010 and 15% by 2015. As the windiest country in Europe, the UK is in a very good position to fulfil the targets by installing many wind parks in the relatively shallow waters extending into the North Sea. In this article, the author describes the legal implications for offshore wind farms.
The UK offshore wind energy sector is booming at the moment. This is largely because of the UK government’s ‘Renewables Obligation’ targets for the generation of electricity from renewable sources of 10% by 2010 and 15% by 2015. As the windiest country in Europe, the UK is in a very good position to fulfil the targets by installing many wind parks in the relatively shallow waters extending into the North Sea. In this article, the author describes the legal implications for offshore wind farms.
By Jonathan Lux, Partner, Ince & Co, UK
- Category: Articles
Case Study and Cost–Benefit Analysis on Implementation of CBM
The focus of this case study and cost–benefit analysis is an application of a condition-based monitoring (CBM) tool installed in a 700kW wind turbine generator at a project based in the USA. The installation was in response to reports that several wind farms had experienced catastrophic gearbox failures, resulting in exorbitant costs and lost revenues. It began in summer 2003 with a cooperative pilot study, the objective being implementation of a ‘trial installation’ that would demonstrate the benefits of a CBM system on a wind turbine to help prevent catastrophic failures.
By Staff Writer, Prasentia, and Roland Kewitsch, Product Manager, Schenck-Trebel, USA
- Category: Articles
Assessing Their Potential Impact on Project Profitability
By Bernard Chabot, Senior Expert, ADEME, France
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Wind power generates CO2-free electricity and so it can also generate ‘carbon credits’ attached to each delivered kWh. If an environmental derivative market is available, the profitability of a wind power project will result from selling electricity to the energy market and also from selling ‘carbon credits’ on such a derivative market. And this will be more and more possible as the Kyoto Protocol and its attached main ‘flexibility mechanism’ the Clean Development Mechanism (CDM) enter into force in 2005 together with the European Trading System (ETS). This article describes a simple and reliable method to assess the increase in profitability by selling carbon credits.
By Bernard Chabot, Senior Expert, ADEME, France