Abstract: Provided is a method for controlling at least two frequency-converter-based infeeders. The method includes specifying a first droop for a first frequency-converter-based infeeder and specifying a second droop for a second frequency-converter-based infeeder, where the second droop is different from the first droop. The method includes, controlling the first frequency-converter-based infeeder in dependence on the first droop, and controlling the second frequency-converter-based infeeder in dependence on the second droop.

Abstract: Provided is a method for feeding electrical power into an electrical supply network having a network voltage using a wind turbine having an inverter, which has a DC voltage intermediate circuit having an intermediate circuit voltage and a chopper circuit connected to the intermediate circuit for discharging electrical energy from the intermediate circuit. The method includes feeding electrical power into the network in a normal operation if no network fault has been detected, detecting a fault if the network voltage falls below an undervoltage value, interrupting or reducing the feed if the fault has been detected, and ending the interruption or reduction if the end of a network fault is detected. During the fault and/or from the end of the fault, the fed-in power is limited to a limit, and, to limit the power, the intermediate circuit voltage is limited using the chopper circuit depending upon the limit.

Abstract: The invention relates to a method for feeding electrical power into an electrical supply grid. The method includes rectifying a first AC voltage of an electrical power, produced by a generator, into a first DC voltage and increasing the first DC voltage to a second DC voltage such that the second DC voltage has a step-up ratio in relation to the first DC voltage. Alternatively, the method includes rectifying the first AC voltage into the second DC voltage without producing the first DC voltage. The method includes inverting the second DC voltage into a second AC voltage for feeding electrical power into the electrical supply grid depending on an feed setpoint value and setting the second DC voltage depending on the feed setpoint value and actual value. The second DC voltage is increased depending on an increase in the feed setpoint voltage or actual value.

Abstract: A method for attenuating low-frequency oscillations in an electrical power supply grid by means of a feed device which feeds into the electrical power supply grid, in particular a wind power installation, wherein the electrical power supply grid has a grid voltage and a grid frequency, comprising the following steps: picking up a grid signal having the low-frequency oscillations, splitting a total frequency range of the grid signal in which oscillations to be attenuated are to be expected into a plurality of partial frequency ranges, each having a lower and an upper range frequency, performing in each case one frequency analysis of the grid signal for each partial frequency range in order to identify in each case one or more oscillations having an oscillation frequency in the partial frequency range, if present, identifying a low-frequency oscillation to be attenuated as target oscillation depending on the frequency analyses of all of the partial frequency ranges, detecting the target oscillation at least acc

Abstract: A method for storing measured values of a wind turbine or a wind farm comprises recording several chronologically sequential measured values of a measured variable. The method also comprises acquiring a change between a previous measured value of the recorded measured values and the chronologically subsequent measured value of the recorded measured values and comparing the change with an adjustable or predefined threshold value. The method further comprises storing the subsequent measured value in a case where the change lies above the predefined threshold value, or discarding the subsequent measured value in a case where the change lies below the predefined threshold value. Embodiments further relate to a wind farm controller and to a wind farm with a wind farm controller.

Abstract: Provided is a method for identifying low-frequency oscillations, in particular subsynchronous resonances, in an electrical supply network, wherein the electrical supply network has a line voltage with a nominal line frequency, comprising the steps: detecting at least one electrical signal of the electrical supply network as at least one test signal and filtering and/or transforming the at least one detected test signal into at least one check signal, temporal derivation of the at least one check signal or difference formation of temporally separated values of the check signal, in order to obtain a gradient signal in each case, identifying the presence of a low-frequency oscillation if the gradient signal or at least one of the gradient signals meets a predetermined check criterion, in particular at least one predetermined check limit is exceeded.

Abstract: A method for attenuating low-frequency oscillations in an electrical power supply grid by means of a feed device which feeds into the electrical power supply grid, in particular a wind power installation, wherein the electrical power supply grid has a grid voltage and a grid frequency, comprising the following steps: picking up a grid signal having the low-frequency oscillations, splitting a total frequency range of the grid signal in which oscillations to be attenuated are to be expected into a plurality of partial frequency ranges, each having a lower and an upper range frequency, performing in each case one frequency analysis of the grid signal for each partial frequency range in order to identify in each case one or more oscillations having an oscillation frequency in the partial frequency range, if present, identifying a low-frequency oscillation to be attenuated as target oscillation depending on the frequency analyses of all of the partial frequency ranges, detecting the target oscillation at least acc

Abstract: Provided is a method of controlling a wind turbine group having a plurality of wind turbines. Each wind turbine generates electrical power as wind turbine output power for feeding into an electrical supply network. The group feeds a group power output into the network at a grid connection point, and the group power output is substantially formed as the sum of all the turbine power outputs of the group. A maximum group power output is specified for limiting the group power output, a control value for compliance with the maximum group power output is transferred to each wind turbine in the group in order to limit the output power of the respective wind turbine to a maximum value defined by the control value, and a control relationship is determined between potential control values and potential group power outputs using the control relationships and depending on the maximum group power output.

Abstract: Provided is a method of feeding electric reactive power using a wind farm comprising wind turbines. The wind farm feeds a wind farm active power output and the wind farm active power output includes individual plant active power outputs each generated by one of the wind turbines. The wind farm feeds a wind farm reactive power output into the electrical supply network and the wind farm reactive power output includes individual plant reactive power outputs each generated by one of the wind turbines. The method includes determining a total wind farm reactive power output to be fed in by the wind farm and calculating, for each wind turbine, an individual plant reactive power output to be generated. The individual plant reactive power output is determined depending on the individual plant active power output and depending on the wind farm reactive power output to be fed in.

Abstract: Provided is a method for operating a wind power installation including starting a discharge operation of an electrical store of an uninterruptible power supply, in particular at a specific time; performing the discharge operation until the electrical store has a predetermined discharge voltage; detecting a discharge current of the electrical store during the discharge operation; and determining a capacity of the electrical store from the detected discharge current.

Abstract: A method for operating a wind farm having a plurality of wind power installations is provided. The installations each comprise an aerodynamic rotor, and the rotors each have an aerodynamic characteristic value. The method includes: obtaining a setpoint power value of the wind farm, in particular a setpoint value of the electrical power of the wind farm to be fed in, ascertaining an actual power value of the wind farm as the sum of actual electrical powers of the operated wind power installations, determining a permissibility of a power-reduced operating mode of each of the wind power installations of the wind farm on the basis of the associated aerodynamic characteristic value, and operating the wind power installations of the wind farm such that each operated wind power installation is operated in a permissible operating mode and the ascertained actual power value does not exceed the obtained setpoint power value.

Abstract: Provided is a method for operating a wind turbine having a generator and a rotor with rotor blades. The method includes generating electrical power from wind using the generator, using a first part of the generated power as an auxiliary component for supplying auxiliary devices of the turbine used for operating the turbine, where the auxiliary component varies up to a limit. The method includes feeding a second part of the generated electrical power into a grid as a feed-in component, checking the grid for a grid fault that does not allow feeding power into the grid and continuing the operation of the turbine when the fault is detected. The generation of power from wind is reduced to a cut-back power that corresponds to the limit the auxiliary component for operating the auxiliary devices is used from the cut-back power and remaining residual power of the cut-back power is consumed.

Abstract: Provided is a method for controlling at least two frequency-converter-based infeeders. The method includes specifying a first droop for a first frequency-converter-based infeeder and specifying a second droop for a second frequency-converter-based infeeder, where the second droop is different from the first droop. The method includes, controlling the first frequency-converter-based infeeder in dependence on the first droop, and controlling the second frequency-converter-based infeeder in dependence on the second droop.

Abstract: Provided is a method for operating a wind power installation including starting a discharge operation of an electrical store of an uninterruptible power supply, in particular at a specific time; performing the discharge operation until the electrical store has a predetermined discharge voltage; detecting a discharge current of the electrical store during the discharge operation; and determining a capacity of the electrical store from the detected discharge current.

Abstract: A security apparatus for data exchange of a component of a wind turbine or a wind farm, in particular a wind farm controller, with a remote computer. In that case the security apparatus includes a first data interface for connecting a component by way of a first data connection and a second data interface for connection to the remote computer by way of second data connection. In addition the security apparatus includes a third data interface for receiving a switching signal by way of a third data connection, a separable internal data connection between the first data interface and the second data interface and a switching unit which is adapted in dependence on the switching signal to separate and/or make a physical connection of the internal data connection. A system having such a security apparatus and a method of data exchange with a component of a wind turbine and/or a wind farm.

Abstract: A method for rebuilding an electric supply grid of a grid operator by means of at least one wind power installation, wherein the electric supply grid has a first grid section and at least one further grid section, wherein the first grid section is connected to the at least one wind power installation and has a first grid nominal voltage, the first grid section is coupled to the at least one further grid section via at least one switching device in order to transmit electric energy between the grid sections, wherein the at least one switching device is set up to disconnect the first grid section from the at least one further grid section in the event of a fault, comprising the steps of operating the at least one wind power installation in an observation mode if the fault occurs, wherein the wind power installation does not feed the first grid section in the observation road and a status of the first grid section is checked, and operating the at least one wind power installation in a grid rebuilding mode if the

Abstract: Provided is a method for feeding electrical power into an electrical supply network having a network voltage using a wind turbine having an inverter, which has a DC voltage intermediate circuit having an intermediate circuit voltage and a chopper circuit connected to the intermediate circuit for discharging electrical energy from the intermediate circuit. The method includes feeding electrical power into the network in a normal operation if no network fault has been detected, detecting a fault if the network voltage falls below an undervoltage value, interrupting or reducing the feed if the fault has been detected, and ending the interruption or reduction if the end of a network fault is detected. During the fault and/or from the end of the fault, the fed-in power is limited to a limit, and, to limit the power, the intermediate circuit voltage is limited using the chopper circuit depending upon the limit.

Abstract: Provided is a method of supplying at least one component of a wind turbine with energy. The energy during operation of the wind turbine is taken from energy generated using a generator of the wind turbine and provided for supply to the at least one component of the wind turbine. Provided is an energy supply device for performing the method and a wind turbine having the energy supply device.

Abstract: Provided is a method for operating a wind power installation or a wind farm with a number of wind power installations for exchanging electrical power between the wind farm and an electrical supply grid. Each wind power installation has one or more feeding-in devices. The wind power installation or the wind farm is connected to the electrical supply grid by a grid connection point. The power is exchanged by way of the grid connection point. One or more of the feeding-in devices operate as voltage-influencing units and one or more of the feeding-in devices operate as current-influencing units. The voltage-influencing units and the current-influencing units also operate in a voltage-influencing and current-influencing manner during undisturbed operation of the electrical supply grid.

Abstract: A method for starting a farm grid of a wind farm is provided. The energy generation grid has at least one grid connection point connected to an electrical supply grid and the energy generation grid, in a normal operating mode, exchanges electrical power with the electrical supply grid via the grid connection point. The method includes selecting an establishment mode, different than the normal operating mode, if the electrical supply grid has a voltage drop or the energy generation grid is isolated from the electrical supply grid and operating the energy generation grid in the establishment mode. The establishment mode at least one voltage-influencing wind power installation for providing a wind farm grid voltage and at least one current-influencing wind power installation that synchronizes to the energy generation grid voltage. The wind power installations in total provide an electrical power at the level of an inherent need of the grid.