Abstract: A method for determining an energy yield loss of a first wind turbine (1-49) of a wind farm (51) that includes a plurality of wind turbines (1-49). The first wind turbine (1-49) is operated in a reduced energy yield mode that is outside an energy-optimized normal operating mode and a reduced energy yield of the first wind turbine (1-49) is determined. At least one second wind turbine (1-49) is selected according to a pre-determinable criterion. The energy yield of the at least one second wind turbine (1-49) is determined and depending upon the energy yield of the at least one second wind turbine (1-49), an energy yield potential of the first wind turbine (1-49) is determined. The difference between the energy yield potential of the first wind turbine (1-49) and the determined reduced energy yield is formed.

Abstract: An offshore wind farm can include at least two wind energy installations for generating electrical power from wind, at least two acoustic warning devices, and a visibility measuring device for detecting visibility. After detection of a visibility below a visibility limit value, an activation signal can be applied to the at least two acoustic warning devices. One or more synchronization modules can be provided which determine the points in time of the acoustic signals to be emitted by at least one of the acoustic warning devices in relation to the acoustic signals of the other acoustic warning devices. Accordingly, this facilitates the navigation along an offshore wind farm and enables safe circumnavigation. Also, the impression of a contiguous area can be conveyed to the ships by the synchronized emission of the warning signals.

Abstract: The invention relates to a method for performing an oil change on a wind power plant, comprising the steps of rotating the rotor (3) to a maintenance position, subsequently draining the oil out of a first variable-speed gearbox (6), filling the first variable-speed gearbox (6) with fresh oil, draining the oil out of a second variable-speed gearbox (6?) that is oriented differently than the first gearbox, and filling the second drive device (6?) with fresh oil. The variable-speed gearboxes each comprise a sump (63) having a first outlet opening (65) and a mirrored sump (64) on the opposite end of the housing thereof having a second outlet opening (66). Thus, the rotor (3) does not need to be rotated further during the oil change. The oil change can be performed simultaneously on several or all variable-speed gearboxes, reducing time and personnel expenses. The invention further relates to a correspondingly designed drive device and to an oil changing device.

Abstract: A wind farm includes a plurality of wind energy installations, a transfer point at which electrical energy produced by the wind energy installations is transferred to a public electricity grid system and for which nominal values are preset, and a measurement sensor configured to measure electrical actual values at the transfer point. The wind farm also includes a master regulator associated with an upper control level and configured to use upper nominal values and upper actual values at the upper control level to determine a preset for a lower control level, and a plurality of submaster regulators associated with the lower control level and configured to use the preset as a lower nominal value and, on the basis of the lower nominal value and a lower actual value, determine presets for the wind energy installations. A high level of control accuracy can thus be achieved even in large wind farms.

Abstract: A wind turbine having a generator for generating electrical energy and a transformer is disclosed. The transformer is designed to receive electrical energy from the generator on a secondary side and to discharge said electrical energy again on a primary side at a higher voltage. The wind turbine also comprises a temperature monitoring means for the transformer. The voltage supply to the temperature monitoring means is fed from the primary side of the transformer. The temperature monitoring means is thereby independent of the control system of the wind turbine. The temperature monitoring means reduces the risk of the transformer overheating. A method for operating such a wind turbine is also disclosed.

Abstract: Provided herein is a wind energy installation including a generator for production of electrical energy, a rotor which drives the generator and has variable pitch rotor blades and a central control device, and individual pitch devices provided individually for the rotor blades. The individual pitch devices may include an adjustment drive, a communication link to the central control device and a regulator, the rotor blades being adjustable in order to slow down the wind energy installation to a shut-down position. The individual pitch devices may also include a disturbance situation detector which is designed to identify abnormal operating states and to move the rotor blades to a shut-down position. Also provided herein is the method of operating such a wind energy installation.

Abstract: Operating a wind farm in which the power generated by the wind energy installations is fed to a power supply system via a system internal to the wind farm and via a substation is disclosed. The farm director of the wind farm can ascertain a standard target voltage value and transmit it to the control units of the individual wind energy installations on the wind farm, which can use an overall factor to regulate the reactive power generated by a wind energy installation. The overall factor can be calculated from the difference between the actual voltage across the wind energy installation and the target voltage value, multiplied by a gain factor. On account of the impedance in the internal system of the wind farm, wind energy installations situated far away from the substation thus generate less reactive power than the wind energy installations which are situated close to the substation.

Abstract: A method for operating a wind farm comprising several wind turbines that are connected to an internal grid of the wind farm is disclosed. In said method, during a mains failure the electrical consumers of the wind turbines are supplied with electrical energy by a mains replacement supply unit. Each electrical consumer of the wind turbines is assigned to one of at least two groups and according to the group assignment is always switched on by an operation control unit when required, or only switched on if there is a sufficient power reserve. The wind farm is designed to carry out said method.

Abstract: Controlling a converter of a wind turbine is disclosed. The converter is connected to a rotor of a doubly fed asynchronous generator in order to feed electrical energy into an electric network. The converter comprises a network-side inverter, a generator-side inverter, and a controller, which outputs target values for demanded reactive power to at least one of the inverters. A reactive power target signal is determined for the portion that the network-side inverter contributes to the demanded reactive power QT, a slip signal is determined from the frequency of the network and the rotational speed of the generator, a gain value is calculated according to the slip signal, and the gain value is modified according to the reactive power target signal for the network-side inverter. The distribution of the reactive power between the two inverters is thus optimized over a wide operating range, not only at individual predetermined operating points.

Abstract: A wind energy installation control device includes a wind rotor, a generator driven by the wind rotor, a torque control unit configured to control a torque of the generator, and a control system. The control system includes a detector configured to identify a grid dip and an end of the grid dip, a residual torque transmitter configured to provide a set point for a torque of the generator after identification of the grid dip, and an initializer configured to initialize a component of the torque control unit at the set point. Accordingly, upon return of grid power after a grid dip, the vibration behavior of a wind power system can be significantly improved. Overload of a drive train upon return of grid voltage can thus be reduced.

Abstract: A wind energy plant comprising a rotor having blades and a generator driven by said rotor for generating electric energy. The pitch of the blades can be adjusted and a pitch system for adjusting the pitch angle of the blades is provided, which is supplied by a hub power source. An additional electric load is provided on the hub. A pitch power control device is provided which dynamically distributes the power of the hub power source between the pitch system and the additional electric load and further acts on the pitch system such that the power consumption thereof during high-load operation is reduced. Thus, the power consumption of the pitch system during high-load operation can be reduced and additional power provided for operating the additional load. Even high-performance additional loads, such as a blade heater, can be operated in this way, without having to boost the hub power source.

Abstract: A wind energy installation having a wind rotor, a generator which is driven thereby and interacts with a converter in order to produce electrical power, rotation-speed regulation and converter control which interacts therewith, wherein the rotation-speed regulation outputs a nominal rotation speed signal (nref). Furthermore, additional regulation is provided, which has an input for an additional power and is designed to produce a rotation speed change signal therefrom, taking account of a rotator inertia moment, and to output this as an output signal, which is added to the nominal rotation speed signal via a logic element. Kinetic energy is taken from the wind rotor in a controlled manner by reducing the rotation speed and is converted by the generator to additional electrical energy. This allows primary regulation power to be made available deliberately by rotation speed variation, to be precise even in unsteady wind conditions.

Abstract: A wind power plant, including a generator driven by a rotor in order to generate electrical power and a controller that includes a pitch module for adjusting a pitch angle of blades of the rotor. The controller has an input for a required power reserve and determines a target pitch angle depending on an operating point of the wind power plant. A secondary pitch controller is also provided, which includes a detector for available power and a dynamic offset module. Input signals for the available reserve power determined by the detector, the required reserve power and the generated electrical power are applied to the dynamic offset module, which is designed to determine a value for a pitch angle offset. An activation element varies the target pitch angle by the pitch angle offset.