This paper investigates the possibility of using active individual blade pitch control for positioning moored ocean current turbines within an array. Using a numerical simulation of a representative ocean current turbine it is shown that harmonic blade oscillations with amplitudes of 1.5° can be used to displace an ocean current turbine laterally by a distance equal to one rotor diameter, when the mooring cable length is approximately 30 times the diameter of the rotor blade. For current flow directions that would result in a downstream turbine operating in the wake of an upstream system at a distance of 10 diameters, this technique could be used to reduce the power loss of the downstream system from about 50% (caused by the reduced flow speed available in the turbine wake) to the 1.2% power loss associated with the suggested control approach.
VanZwieten, J. H., Pyakurel, P., Ngo, T., Sultan, C., & Xiros, N. I. (2016). An assessment of using variable blade pitch for moored ocean current turbine flight control. International Journal of Marine Energy, 13, 16-26. https://doi.org/10.1016/j.ijome.2016.01.002