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 (ω) of said turbine (2), —a motor displacement control system (15) for continuously receiving said speed signal (11s) and said rotational speed signal (12s) and arranged for calculating a control signal (16), —a volumetric displacement control actuator (17) on said hydrostatic motor, arranged for receiving said control signal (16) for continuously adjusting a volumetric displacement (d) of said hydrostatic motor (8) for maintaining a set turbine tip speed ratio (tsrset) and thereby providing an improved power efficiency of the power production system (1) during fluctuations in said fluid speed (v).
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 (ω) of said turbine (2), —a motor displacement control system (15) for continuously receiving said speed signal (11s) and said rotational speed signal (12s) and arranged for calculating a control signal (16), —a volumetric displacement control actuator (17) on said hydrostatic motor, arranged for receiving said control signal (16) for continuously adjusting a volumetric displacement (d) of said hydrostatic motor (8) for maintaining a set turbine tip speed ratio (tsrset) and thereby providing an improved power efficiency of the power production system (1) during fluctuations in said fluid speed (v).