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Low cost variable speed system for stall wind turbines



The objective of the project is the development of a variable speed system for wind turbines with typical stall control configuration (STALLABLE). The scope is the development of the whole system, including control boards, control software and power circuitry, manufacture of prototypes and full scale testing on a wind turbine of 600 kW of nominal power. The cost reduction is to be attained by concentrating all the control algorithms and procedures within a fast microprocessor able to directly control the IGBT and the energy conversion, thus dramatically reducing the complexity of the hardware.
Technical approach

A detailed analysis of the energy production of stall-controlled wind turbines with special attention to the efficiency of the whole conversion process for the full range of operational power. Losses caused by the energy conversion needed for variable speed have to be accurately calculated by generator and system modelling. The detailed analysis will provide information about the efficiency improvement and for the development of the control strategies and decide the optimal configuration and characteristics of the system.
Variable speed system design, providing a general layout of the system, control features, integration within the wind turbine and possible implementation on existing turbines. The system will be divided in the different components and detailed technical specifications will be produced for each one. To final develop the system an implement the findings, Component design will be carried out, dealing with the detailed design of the components: Power circuitry, Control boards, Mounting specification and Software development.

In order to verify system features, Facility tests will be carried out in a simulated environment. Tests will verify static performance as well as dynamic response and control speed. To assess system performance in real operation in a commercial turbine, the system will be implemented and tested in automatic operation with detailed load, power and operation measurement, in a high-wind and complex-terrain site.

The expected achievements

The expected achievements are the improvement of the power production of stall controlled wind turbines by means of a system easy to install in standard wind turbines. The improvement in energy production may vary as function of the site and turbine characteristics between 3 1nd 15%. The loading of the drive train will be improved, the noise emision dramatically reduced at low wind speed, the power factor set to 1 and the flicker induced by grid connection will disappear.


Ecotecnia Sociedad Cooperativa Catalana Ltd.
23 1,Cl. Amistad
08005 Barcelona

Participants (2)

3,Elektrovägen 3
412 96 Goeteborg
Quest Gothenburg AB
41705 Göteborg