By Bungo Ezawa, Head of Department Renewable Energies – Wind Energy, Lahmeyer International, Germany

The Research and Engineering Involved in Confidently Achieving 70m Monitoring

As the height of wind turbines continues to soar, it has become increasingly necessary to achieve ‘bankable data’ from wind monitoring sensors at higher levels. Potential wind development sites are often remote, so monitoring masts need to be easily transported, lightweight and possible to construct with minimal effort. For masts in excess of 60m to survive extreme conditions, the tower sections must have greater strength without excessively compromising the mast weight. In this article, Geoff Watson of Western Windpower describes the development programme for the company’s new 70m HiMast.

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

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

New turbines above 3MW are being developed at a rapid rate in order to maximise energy yields. Therefore turbine components also have to be upgraded. A transformer is required to step up the voltage from the generator (400 to 3000V) to a medium voltage level. Safety and fire behaviour of transformers is an important issue for our industry. Fire damage accounts for between 9 and 20% of wind power insurance claims. In this article, the authors compare the safety and fire behaviour of dry-type transformers with high temperature liquid-filled transformers.