Case study

Demonstrating the applicability of a novel wind turbine technology

We helped our partners to understand the performance implications of various combinations of their control strategy.


Kohana Technologies Inc. has developed an active aerodynamic control system for wind turbines. This system provides the ability to locally affect the aerodynamics on the blade (increasing drag and reducing lift) through separation, by ejecting air along the suction side of the blade towards the leading edge. This new control methodology, known as ‘Blown Wing Technology’, provides an ability to control the generator speed in full load conditions without affecting wear on the current pitch system.

Our team worked with Kohana and Vestas to integrate their design into a Vestas V110 2MW model, quantifying the impact on the relevant IEC 61400 load cases.

Our work

To understand the impact of this technology, the system requirements were first investigated and quantified. This involved computational fluid dynamics’ (CFD) simulations, to understand the various pressure losses and flow rates of the delivery system and the subsequent rate at which it could affect the aerodynamic lift and drag response on the blade.

After characterising the actuator model, we then aided in integrating this model into the aeroelastic simulation used to model a Vestas 2MW turbine, through construction of an innovative flow network model. An appropriate activation strategy was then defined to fully integrate the system and its controller into the existing turbine controller.



We helped our partners understand the performance implications of various combinations of the control strategy (i.e. where in the operating envelope it was best to implement this technology). We discovered that under certain conditions, a 15% tower base extreme load reduction in IEC 61400 DLC 2.3, and a 15% tower base extreme load reduction with a 2% extreme generator speed reduction in IEC 61400 DLC 1.3, could be achieved. Through a detailed design and analysis methodology, these results helped to demonstrate the applicability of this technology.

Blown Wing system

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