The effects of two types of flow control devices, vortex generators (VGs) and Gurney flaps (GFs), on the power output performance of a multi-megawatt horizontal axis wind turbine is presented. To that end, an improved blade element momentum (BEM)-based solver has been developed and BEM-based computations have been carried out on the National Renewable Energy Laboratory (NREL) 5 MW baseline wind turbine. The results obtained from the clean wind turbine are compared with the ones obtained from the wind turbine equipped with the flow control devices. A significant increase in the average wind turbine power output has been found for all of the flow control device configurations and for the wind speed realizations studied in the present work. Furthermore, a best configuration case is proposed which has the largest increase of the average power output. In that case, increments on the average power output of 10.4% and 3.5% have been found at two different wind speed realizations. The thrust force and bending moment in the root of the blade have also been determined and compared with the values of the clean wind turbine. A residual increase in the bending moment of less than 1% has been found.

The relevance of renewable energies is undeniable, and among them, the importance of wind energy is capital. A lot of literature has been devoted to the control techniques that deal with the optimization of the energy produced, but the maintainability of the individual wind turbines and of the farms in general is also a fundamental factor to take into account. In this paper, the authors address the general problem of knowing in advance the resonance frequencies of the power system of a wind turbine, with the underlying idea being that those frequencies should be avoided and that resonances do not occur only due to mechanical phenomena, but also because of electrical phenomena that in turn are influenced by control and optimization techniques. Therefore, the availability of that information embedded in the optimization techniques that control a wind turbine is of major importance. The main purpose of this paper was accomplished through two related objectives: the first was to obtain a mechatronic model (using a lumped parameters model of two degrees of freedom) of the drive train in the Laplace domain oriented to subsequently perform the described analysis. The second was to use that model to determine analytically the number and the value of the resonance frequencies from the generator angular velocity in such a way that such information could be used by any control algorithm or even by the mechatronic system designers. We assessed through experimental validation using a real 100 kW wind turbine that these two objectives were reached, demonstrating that the different vibration modes were detected using only the generator angular velocity.

Lan honetan zehar fresaketa bidezko simulazioa lantzen da tornuko ebaketa etenaren bitartez. Finkatutako helburu nagusia erremintaren jaulkitze aurpegian lortuko diren tenperaturak ezagutzea izango da ebaketa prozesuan. Helburu hau lortzeko, torneaketa prozesutik fresaketa prozesura estrapolazio bat egingo da, luzeran artekatutako pieza torneatzen bada posible izango dena, torneaketa fresaketa izango balitz bezala simulatuz, fresaketa ebaketa etena denez. Proba baldintzetan tenperatura neurketa hauek gauzatzeko K motako termoparea erabiliko da, zein jaulkitze aurpegiarekiko 0.5mm-eko distantziara kokaturik egongo den. Bero transmisiozko modelo teoriko batetan oinarrituz kalkulatuko dugu kontaktuko batazbesteko tenperatura. Ebaketa baldintza ezberdinetarako proba ezberdinak garatu dira, sakontasunean deskribatuko ditugunak. Honetaz gain, ebaketa jarrai eta etenean lortuko diren tenperatura diferentziak aztertuko dira ,ebaketa denbora berbera erabiliz alde batetik, eta ebaketa eraginkorraren luzera berbera erabiliz bestetik.