Abstract: A slip ring unit for an electric generator is provided. The slip ring unit includes a slip ring attachable to a rotor shaft of the electric generator, a plurality of sliding contacts arranged along a circumference of the slip ring, to provide an electrical connection with the slip ring, at least one temperature sensor for measuring a temperature inside the slip ring unit, a fan for providing a cooling flow in the slip ring unit, and a controller connected to the fan for controlling the cooling flow rate generated by the fan, the controller being connected to the at least one temperature sensor. The at least one temperature sensor is attached to at least a holder for supporting the sliding contacts. The controller is configured in such a way that the cooling flow rate is generated depending on the temperature measured by the at least one temperature sensor.

Abstract: A method for controlling the reactive power exchange of a DFIG wind facility with the grid is provided. The method includes determining a grid side converter reactive power thermal limit value and determining the value of the required DFIG magnetizing reactive power to be consumed by the stator. Then setting dynamically the sharing of the reactive power between the stator and the GSC such that the GSC reactive power value is the difference between the reactive power demand of the DFIG wind facility and the magnetizing reactive power consumed by the stator. Afterwards operating the DFIG wind turbine facility such that the absolute value of GSC reactive power is adjusted to be below the grid side converter reactive power thermal limit value value. An arrangement and a wind turbine are also provided.

Abstract: A wind power plant for providing electrical power to a utility grid is provided, the wind power plant including: at least one wind turbine having a wind turbine generator coupled to a wind turbine rotation shaft to which plural rotor blades are mounted, the wind turbine providing electric power at an output terminal; at least one power conversion system, each including: a plant motor electrically coupled and configured to receive the electric power from the output terminal of the at least one wind turbine and convert it into rotational power of a plant motor shaft; a plant generator mechanically coupled to the plant motor shaft and electrically coupleable to the electric utility grid.

Abstract: A wind turbine electrical power generating system includes a first generator configured to be mechanically coupled to a rotor, a second generator configured to be mechanically coupled to the rotor; and an electrical power conversion system including at least a first and a second power converter section. The first power converter section is electrically coupled between a rotor winding of the first generator and a coupling point and a stator winding of the first generator is electrically coupled to the coupling point such that only a fraction of electrical power generated by the first generator passes through the power conversion system. The second power converter section is electrically coupled between an electrical power output of the second generator and the coupling point such that the electrical power provided by the second generator to the coupling point passes through the power conversion system.

Abstract: The invention provides methods and systems for real-time monitoring of the insulation state of wind-powered generator windings comprising the following steps: a) capturing in real-time, during a predetermined time period (in situations where the generator is synchronized to the electrical network but is not yet couplet thereto as well as in situations where the generator is producing energy) the values of one or more electrical and vibration variables of the generator; b) obtaining in real-time, the temporal evolution of the vibration and of the inverse components of electrical variables at one or more predetermined frequencies; c) identifying a possible generator insulation fault when the inverse component of at least one electrical variable and/or one vibration at a predetermined frequency exceeds an absolute threshold or a temporal increase threshold pre-sets.

Abstract: This invention relates to a synchronous generator for wind turbines comprising a rotor (20) and a stator (10), wherein the stator (10) comprises a plurality of induction coils (11) of a high-temperature superconducting material arranged to generate a magnetic field. The use of the superconducting stator, instead of a superconducting rotor, allows simplifying the refrigeration system, thus eliminating, for example, the rotating joints for cryogenic gas and the rotating joints for high-purity helium gas.

Abstract: The invention provides methods and systems for real-time monitoring of the insulation state of wind-powered generator windings comprising the following steps: a) capturing in real-time, during a predetermined time period (in situations where the generator is synchronized to the electrical network but is not yet couplet thereto as well as in situations where the generator is producing energy) the values of one or more electrical and vibration variables of the generator; b) obtaining in real-time, the temporal evolution of the vibration and of the inverse components of electrical variables at one or more predetermined frequencies; c) identifying a possible generator insulation fault when the inverse component of at least one electrical variable and/or one vibration at a predetermined frequency exceeds an absolute threshold or a temporal increase threshold pre-sets.