Optimal aerodynamic energy capture strategies for hydrostatic transmission wind turbine

In this paper, we propose a control strategy for a wind turbine that employs a hydrostatic transmission system for transmitting power from the wind turbine rotor via hydraulic transmission line to a ground level generator. Wind turbine power curve tracking is achieved by controlling the hydraulic pump volumetric displacement and, at the other end of the hydraulic line, the hydraulic motor volumetric displacement is controlled so that the overall transmission loss is minimized. Control strategy and system efficiency of a double wind turbine system sharing hydraulic pipes, a hydraulic motor, and a generator are also studied.