Abstract: A closed loop turbine speed control system for a turbine power production system including a closed loop hydrostatic transmission system for the transfer of energy from a wind turbine rotor to a generator. A displacement actuator is arranged for receiving a displacement control signal from the control system and for controlling a displacement of the displacement motor. The control system includes a turbine rotor speed feedback control loop for calculating the displacement control signal based on deviations of a turbine rotor actual rotational speed from a turbine rotor set rotational speed. In addition a hydraulic pressure meter measures the hydraulic pressure of the hydrostatic system and provides a hydraulic pressure signal as an input to a pressure feedback control loop for stabilizing the displacement control signal based on the hydraulic pressure signal.

Abstract: A turbine (2) driven electric power production system (1),—said turbine (2) arranged for being driven by a fluid (3) having a fluid speed (v) varying in time,—said turbine (2) connected to a hydrostatic displacement pump (6) further connected to a hydrostatic displacement motor (8) as part of a closed loop hydrostatic transmission system (7),—said motor (8) arranged for driving an electrical generator (9) supplying AC power (10) at a frequency (fg) near a given desired frequency (fdes), characterized by a closed loop system arranged for controlling a volumetric displacement (13) of the hydrostatic motor (8), comprising—a fluid speed meter (11m) arranged for producing a speed signal (11s) representing a speed (v) of said fluid (3), and—a rotational speed meter (12m) arranged for providing a rotational speed signal (12s) representing a rotational speed measurement (?) of said turbine (2), —a motor displacement control system (15) for continuously receiving said speed signal (11s) and said rotational speed signa

Abstract: A turbine (2) driven electric power production system (1), —said turbine (2) arranged for being driven by a fluid (3) having a fluid speed (v) varying in time, —said turbine (2) connected to a hydrostatic displacement pump (6) further connected to a hydrostatic displacement motor (8) as part of a closed loop hydrostatic transmission system (7), —said motor (8) arranged for driving an electrical generator (9) supplying AC power (10) at a frequency (fg) near a given desired frequency (fdes), characterized by a closed loop system arranged for controlling a volumetric displacement (13) of the hydrostatic motor (8), comprising —a fluid speed meter (11m) arranged for producing a speed signal (11s) representing a speed (v) of said fluid (3), and —a rotational speed meter (12m) arranged for providing a rotational speed signal (12s) representing a rotational speed measurement (?) of said turbine (2), —a motor displacement control system (15) for continuously receiving said speed signal (11s) and said rotational speed