Abstract

A system and method for maintaining the rotational speed for the generator and turbine of a wind turbine power production system during a low voltage condition. The system having a closed loop hydrostatic transmission system and an electric generator. The system comprises a control unit, and a flow control valve between the high pressure line and the low pressure line. The flow control valve receives a signal from the control unit and controls a flow of hydraulic fluid from the high pressure line to the low pressure line. The voltage of the electric grid is sent to the control unit which reduces the displacement and controls the flow of the flow control valve when a low voltage condition is detected to maintain the generator rotational speed and the turbine rotational speed during the low voltage condition. The generator can also be re-connected to the grid according to the invention if it drops out if the low voltage duration exceeds the requirements of the grid code.

IPC Classes  ?

• F03D 7/04 - Automatic controlRegulation
• F03D 11/02 - Transmission of power, e.g. using hollow exhausting blades
• F16H 61/40 - Control of exclusively fluid gearing hydrostatic

Abstract

A wind turbine rotor shaft (1), and a nacelle integrated power production system (60) comprising the rotor shaft (1), where the rotor shaft (1) is arranged in a first end (A) for being directly connected to a wind turbine hub (7) carrying wind turbine blades, the rotor shaft (1) comprising in a longitudinal direction of the rotor shaft (1); - one or more eccentric sections (5) eccentric to a rotational axis (O) of the rotor shaft (1), wherein each of the eccentric sections (5) are arranged for driving one or more pistons (3) in respective cylinders (4) when the rotor shaft (1) rotates about the rotational axis (O), where the cylinders (4) are arranged mainly perpendicular to the wind turbine rotor shaft (1), and - a first circular section (20a) being circular around the rotational axis (O) of the turbine rotor shaft (1), the first circular section (20a) arranged between the first end (A) and the one or more eccentric sections (5), and further arranged for being carried by a first bearing (2a).

IPC Classes  ?

• F03D 9/00 - Adaptations of wind motors for special useCombinations of wind motors with apparatus driven therebyWind motors specially adapted for installation in particular locations

Abstract

A system and method for connecting a wind turbine system (1) to an electric grid (100), comprising a rotor (2) an electric generator (20) and a closed loop hydraulic transmission system (10). The electric generator (20) is directly connected to the electric grid (100) via a main breaker (50). A control unit (30) is arranged for adjusting the pitch angle (β) for the hydraulic motor (12) to operate in its recommended operating range, and simultaneously adjusting the displacement (d) to maintain a generator output frequency (ft) within a predefined allowable grid frequency range (Δf) and a difference in phase angle within a predefined allowable phase angle range (Δθ) for a predefined time (Δt), before sending a control signal (33) to the main breaker (50) to connect the wind turbine power production system (1) to the grid (100).

IPC Classes  ?

• F03D 7/02 - Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
• F03D 7/04 - Automatic controlRegulation

Abstract

A wind turbine power production system (1) and a method for controlling a wind turbine power production system (1), with, an electric generator (20) and a closed loop hydraulic transmission system (10) comprising a hydraulic pump (11), and a hydraulic motor (12) with a variable displacement (d). The wind turbine power production system (1) further comprises a digital control unit (30) comprising a Kalman estimator (301), a PI controller (302) and a lookup table (303). The Kalman estimator (301) comprises a pressure signal input, a displacement signal input (si2), an estimated turbine torque signal input (si3), an estimated turbine rotational speed signal output (so1) and an estimated hydraulic pressure signal output (so2).

IPC Classes  ?

• F03D 7/02 - Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
• F03D 7/04 - Automatic controlRegulation

Abstract

A closed loop turbine speed control system (30) for a turbine power production system (1) comprising a closed loop hydrostatic transmission system (10) for the transfer of energy from a wind turbine rotor (2) to a generator (20). A displacement actuator (d) is arranged for receiving a displacement control signal (ds) from the control system (30) and for controlling a displacement of the displacement motor (12). The control system (30) comprises a turbine rotor speed feedback control loop (32) for calculating the displacement control signal (ds) based on deviations of a turbine rotor actual rotational speed (ωp) from a turbine rotor set rotational speed (ω ps). In addition a hydraulic pressure meter (pm) measures the hydraulic pressure of the hydrostatic system (10) and provides a hydraulic pressure signal (ps) as an input to a pressure feedback control loop (31) for stabilising the displacement control signal (ds) based on the hydraulic pressure signal (ps).

IPC Classes  ?

• F03D 11/02 - Transmission of power, e.g. using hollow exhausting blades
• F03D 7/02 - Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor

Abstract

A wind turbine power production system (1) with a closed loop hydrostatic transmission system (10) for the transfer of mechanical energy from a wind turbine rotor (2) to an electric generator (20) where the hydrostatic transmission system (10) comprises a closed loop with a pump (11) and a motor (12) connected by tubes or pipes (13, 14). The assembly of the hydrostatic transmission system (10) and the turbine rotor (2) is arranged to rotate about a vertical axis (8), and the rotating motor (12) is arranged on or near the ground in the tower (4).

IPC Classes  ?

• F03D 11/02 - Transmission of power, e.g. using hollow exhausting blades
• F03D 11/04 - Mounting structures

Abstract

A wind turbine power production system (1) with a closed loop hydrostatic transmission system (10) comprising a closed loop with a pump (11) and a motor (12) connected by tubes or pipes (13,14), for the transfer of mechanical energy from a wind turbine rotor (2) to an electric generator (20) arranged on the ground or near the ground and arranged for being driven by the motor (12). The wind turbine rotor (2) is arranged for rotating about a vertical axis (8) above an electrical swivel (7e) arranged for transferring electrical measurement signals from one or more sensors above the swivel (7e) to a control system (62) below the swivel (7e).

IPC Classes  ?

• F03D 11/02 - Transmission of power, e.g. using hollow exhausting blades
• H01R 39/08 - Slip-rings

Abstract

A wind turbine power production system with a closed loop hydrostatic transmission system for the transfer of mechanical energy from a wind turbine rotor to an electric generator. The hydrostatic transmission system comprises a closed loop with a pump and a motor connected by tubes or pipes. The assembly of the wind turbine rotor and the pump is arranged for rotating about a vertical axis above a swivel arranged for transferring fluid to and from the motor, fluid reservoir and other components arranged below the swivel.

IPC Classes  ?

• F03D 11/02 - Transmission of power, e.g. using hollow exhausting blades

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 (&ohgr;) 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).

IPC Classes  ?

• F03D 7/00 - Controlling wind motors