Abstract: A wind turbine generator 1 supplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiers 4a, 4b and 4c, 4d which generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors 6, 7, 8. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Inverters 10a, 10b, 10c, 10d then convert the d.c. power to a.c. at a fixed frequency and voltage suitable for connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductor 7 and earth, and a respective filter circuit 30 is connected between each of the a.c. outputs of the inverters 10a, 10b, 10c, 10d and earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductor 7 and earth.

Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

Abstract: A hydraulic transmission for a wind turbine that includes a rotor, one or more blades mounted to the rotor, a hydraulic pump mechanically connected to the rotor, and a hydraulic motor. The hydraulic pump and the hydraulic motor are connected to one another by a high pressure circuit. The hydraulic pump maybe a variable displacement hydraulic pump and the hydraulic motor may include a variable displacement hydraulic motor. The wind turbine, including the rotor, the blades of the rotor, the hydraulic pump, and the hydraulic motor may be controlled according to different approaches.

Abstract: A wind turbine generator 1 supplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiers 4a, 4b and 4c, 4d which generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors 6, 7, 8. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Inverters 10a, 10b, 10c, 10d then convert the d.c. power to a.c. at a fixed frequency and voltage suitable for In connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductor 7 and earth, and a respective filter circuit 30 is connected between each of the a.c. outputs of the inverters 10a, 10b, 10c, 10d and earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductor 7 and earth.

Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

Abstract: A hydraulic transmission for a wind turbine that includes a rotor, one or more blades mounted to the rotor, a hydraulic pump mechanically connected to the rotor, and a hydraulic motor. The hydraulic pump and the hydraulic motor are connected to one another by a high pressure circuit. The hydraulic pump maybe a variable displacement hydraulic pump and the hydraulic motor may include a variable displacement hydraulic motor. The wind turbine, including the rotor, the blades of the rotor, the hydraulic pump, and the hydraulic motor may be controlled according to different approaches.

Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

Abstract: A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

Abstract: The present invention relates to an improved wind turbine, of the type which employs doubly fed induction generators (DFIG), and a wind park including the same, which permits the use of lighter weight turbines, with the ability to have greater energy capture, more precise control of asymmetrical phases and enhanced maintenance and support of the grid during fault conditions.

Abstract: Methods for increasing a total reactive power capability of a cluster of wind turbines operationally connected to a grid and systems for carrying out the methods. The method includes generating a voltage value representative of a grid voltage level, determining a total required reactive power value based on the voltage value, and activating at least one wind turbine in said cluster to increase the total reactive power capability from a present value to the required total reactive power value by a predetermined amount.

Abstract: A wind turbine and an associated method for controlling the output current from the wind turbine to an electric power grid and including the wind turbine and the method for controlling the current under conditions of grid voltage variations due to changing grid conditions as in the case when the wind turbine experiences and recovers from a fault.

Abstract: The present invention relates to a wind turbine and an associated method for controlling the output current from said wind turbine to an electric power grid, and, more particularly, to a wind turbine and a method for controlling the current under conditions of grid voltage variations due to changing grid conditions as in the case for example when a wind turbine experiences and recovers from a fault.