A hydraulic control system HCS for controlling a variable ratio transmission of a power generating system. A hydraulic motor/pump unit 140 is operably connected to a superposition gear, and is connected to a hydraulic circuit that comprises an orifice 28 and/or a relief valve 29 that opens at a predetermined hydraulic pressure. The hydraulic circuit switches between a variable low-speed operating mode and a torque limiting high-speed operating mode. In the torque limiting high-speed operating mode the hydraulic motor/pump unit 140 is driven by the superposition gear and drives hydraulic fluid through the orifice 28 and/or relief valve 29 to provide a passive torque limiting function. In the variable low-speed operating mode the hydraulic motor/pump unit 140 drives the superposition gear and the hydraulic control system provides a desired rotor 101 speed by controlling hydraulic fluid flow rate through the hydraulic motor/pump unit 140.

A hydraulic control system HCS for controlling a variable ratio transmission of a power generating system. A hydraulic motor/pump unit 140 is operably connected to a superposition gear, and is connected to a hydraulic circuit that comprises an orifice 28 and/or a relief valve 29 that opens at a predetermined hydraulic pressure. The hydraulic circuit switches between a variable low-speed operating mode and a torque limiting high-speed operating mode. In the torque limiting high-speed operating mode the hydraulic motor/pump unit 140 is driven by the superposition gear and drives hydraulic fluid through the orifice 28 and/or relief valve 29 to provide a passive torque limiting function. In the variable low-speed operating mode the hydraulic motor/pump unit 140 drives the superposition gear and the hydraulic control system provides a desired rotor 101 speed by controlling hydraulic fluid flow rate through the hydraulic motor/pump unit 140.

An automatic adjustment system for a variable-speed wind turbine is provided, having a power vector generator for generating a power vector (P.sub.vec) of wind turbine output power; a mapping unit for establishing relationships (β.sub.vec, ω.sub.vec) between wind turbine output power and rotational speed and pitch angle on the basis of the power vector (P.sub.vec) and an operational trajectory of the wind turbine; a wind speed estimator for estimating a wind speed (v.sub.est); an available power calculator for calculating the available power (P.sub.est) of the wind turbine on the basis of the estimated wind speed (v.sub.est) and the established relationships (β.sub.vec, ω.sub.vec). A method of performing automatic analysis of a wind turbine configuration, a computer program product for carrying out the steps of such a method, and a wind turbine having such an automatic adjustment system are also provided.

An automatic adjustment system for a variable-speed wind turbine is provided, having a power vector generator for generating a power vector (P.sub.vec) of wind turbine output power; a mapping unit for establishing relationships (β.sub.vec, ω.sub.vec) between wind turbine output power and rotational speed and pitch angle on the basis of the power vector (P.sub.vec) and an operational trajectory of the wind turbine; a wind speed estimator for estimating a wind speed (v.sub.est); an available power calculator for calculating the available power (P.sub.est) of the wind turbine on the basis of the estimated wind speed (v.sub.est) and the established relationships (β.sub.vec, ω.sub.vec). A method of performing automatic analysis of a wind turbine configuration, a computer program product for carrying out the steps of such a method, and a wind turbine having such an automatic adjustment system are also provided.

The present invention relates to a system configured to monitor a condition of a rotating system comprising a main bearing, the monitoring arrangement having a first measurement device configured to be arranged at a first location in proximity of the main bearing for determining a first measurement indicative of a current flow at the first location, and a control unit connected to the measurement device. The control unit is further configured to form a first parameter based on the first measurement, match the first parameter with a plurality of predetermined current flow profiles, each of the plurality of predetermined current flow profiles being indicative of a condition of the rotating system, determine, if a matching current flow profile is found, a relevance level for the corresponding condition, and provide an indication of an alarm if the relevance level is above a predetermined threshold.

The present invention relates to a system configured to monitor a condition of a rotating system comprising a main bearing, the monitoring arrangement having a first measurement device configured to be arranged at a first location in proximity of the main bearing for determining a first measurement indicative of a current flow at the first location, and a control unit connected to the measurement device. The control unit is further configured to form a first parameter based on the first measurement, match the first parameter with a plurality of predetermined current flow profiles, each of the plurality of predetermined current flow profiles being indicative of a condition of the rotating system, determine, if a matching current flow profile is found, a relevance level for the corresponding condition, and provide an indication of an alarm if the relevance level is above a predetermined threshold.

A kite comprises: a wing; upper and lower flaps located along at least a portion of an edge of the wing that forms the trailing edge of the wing when the wing is active; a controller configured to generate control signals; and an actuator arrangement configured to change orientations of the upper and lower flaps relative to the wing based on the control signals generated by the controller.

A kite comprises: a wing; upper and lower flaps located along at least a portion of an edge of the wing that forms the trailing edge of the wing when the wing is active; a controller configured to generate control signals; and an actuator arrangement configured to change orientations of the upper and lower flaps relative to the wing based on the control signals generated by the controller.

A wind turbine pitch drive system comprises an electric grid for supplying electrical power, a motor for driving a pitch actuator, an electronic converter for controlling the motor and a back-up energy storage unit for supplying electrical power. The electronic converter comprises a DC-link capacitor bank. The system furthermore comprises a switching device for selectively connecting the DC-capacitor bank link to the back-up energy storage unit, and a frequency generator for controlling the switching device. Also disclosed is a method for protecting a component of the electronic converter.

A braking system for a turbine of a wind powered includes a hydraulic machine connected to a drive shaft of the turbine. A pressure regulating valve in the supply line of the hydraulic machine determines the pressure delivered to the supply line by the hydraulic machine. A control that is responsive to the speed of rotation of the drive shaft modulates the pressure regulating valve so as to increase pressure in the supply line as the rotational speed exceeds a predetermined speed to apply a braking force to the drive shaft.