Abstract: A method of controlling a wind turbine transformer is provided. The transformer has a primary side with a primary winding coupled to a power grid and a secondary side with a secondary winding coupled to an electrical power generating system of the wind turbine. The wind turbine transformer further includes an electronic on-load tap changer having semiconductor switches that are controllable to change a turns ratio of the primary winding to the secondary winding of the wind turbine transformer. The method includes the step of monitoring a voltage on the primary side of the wind turbine transformer, a voltage on the secondary side of the wind turbine transformer, or both. In response to detecting a change in the monitored voltage, the semiconductor switches of the electronic on-load tap changer are automatically controlled to adjust the turns ratio of the wind turbine transformer to compensate for the change.

Abstract: A lightning current transmission system in a wind turbine between a metal band located at the root of each blade and a metal ring located at the nacelle through a lightning current transmission element comprising a conductive portion, an insulating portion and a supporting unit to be joined to the rotor hub. The metal band and the metal ring are configured with protruding parts extended towards the lightning current transmission element. The conductive portion of the lightning current transmission element comprises first and second receptors mounted on a base plate at different heights and oriented in a direction pointing, respectively, to the protruding parts of the metal band and the metal ring.

Abstract: A lightning current transmission system in a wind turbine between a metal band located at the root of each blade and a metal ring located at the nacelle through a lightning current transmission element comprising a conductive portion, an insulating portion and a supporting unit to be joined to the rotor hub. The metal band and the metal ring are configured with protruding parts extended towards the lightning current transmission element. The conductive portion of the lightning current transmission element comprises first and second receptors mounted on a base plate at different heights and oriented in a direction pointing, respectively, to the protruding parts of the metal band and the metal ring.

Abstract: A voltage sag generator device for use in an electrical generator machine such as a wind turbine, connected to an electrical network including one to three parallel transformers connected on one side to the wind turbine via a coupling switch and circuit breakers, and earthed on the other side via circuit breakers and a control switch. The device includes mechanisms for causing short-circuits when the coupling switch and the control switch are actuated in such a way that a voltage sag having the required duration and type is generated, and mechanisms for protecting the transformers during voltage sag generation.

Abstract: The invention relates to a device for generating low-voltage dips in an electrical power generator (2), particularly an aerogenerator, consisting of: a circuit which is disposed between the control cabinet (4) of the generator and the output transformer (3) to the network (30), comprising a transformer (31) and a plurality of in-series impedances (11, 14, 17; 12, 15, 18; 13, 16, 19) for each phase, having switches (24, 25, 26; 20, 21, 22; 27) associated therewith; and short-circuit generator means, selectively actuating the switches as a function of the type of voltage dip required.

Abstract: A voltage sag generator device (30) for use in an electrical generator machine (2) such as a wind turbine, connected to an electrical network (1) including one to three parallel transformers (3, 4, 5) connected on one side to the wind turbine (2) via a coupling switch (7) and circuit breakers (13, 11, 10), and earthed on the other side via circuit breakers (18, 17, 16) and a control switch (6); means for causing short-circuits when the coupling switch (7) and the control switch (6) are actuated in such a way that a voltage sag having the required duration and type is generated; and means for protecting the transformers (3, 4, 5) during voltage sag generation.

Abstract: The invention relates to a device for generating low-voltage dips in an electrical power generator (2), particularly an aerogenerator, consisting of: a circuit which is disposed between the control cabinet (4) of the generator and the output transformer (3) to the network (30), comprising a transformer (31) and a plurality of in-series impedances (11, 14, 17; 12, 15, 18; 13, 16, 19) for each phase, having switches (24, 25, 26; 20, 21, 22; 27) associated therewith; and short-circuit generator means, selectively actuating the switches as a function of the type of voltage dip required.