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 includes a tower provided with rotor blades that are adjusted using a servomotor connected to a pitch circuit and an emergency circuit. During normal operation the rotor blades are actuated by the pitch circuit and during emergency operation are actuated by the emergency circuit. The emergency circuit has an electric energy store, a switching device, connection lines to the servomotor and a protection device which includes comprises a power flow detector module (60) designed for determining whether electric power flows into or from the servomotor and a discharge module designed to limit the voltage and/or current in the emergency circuit in the case of a power flow from the servomotor.

Abstract: A method for controlling a converter of a wind energy installation. The converter is connected to the rotor of a doubly-fed asynchronous generator in order to feed electrical power into an electrical grid and comprises a generator-side inverter, a grid-side inverter, and at least one converter regulator for regulating and/or controlling current output from at least one of the inverters to the doubly-fed asynchronous generator and/or to the electrical grid. The method includes detecting a change in output real power, determining whether the detected change satisfies a predefined condition, and changing a nominal value of reactive power to be output in an opposite sense to a change in real power at the grid-side inverter and in a same sense as the generator-side inverter when the predefined condition is satisfied.

Abstract: A wind energy installation can include a generator which is driven by a rotor and generates electrical power in a multiphase manner for feeding into a network, a converter which is connected to the generator and to the network, and a control system which interacts with the converter and includes a negative sequence system regulation mechanism. The negative sequence system regulation mechanism can include a phase control module configured to determine an electrical variable of the negative sequence system according to the phase. Accordingly, an available current can be provided according to the operating situation for active power or idle power in the negative sequence system regulation mechanism. The negative sequence system regulation mechanism can thus help stabilize the network in the event of asymmetrical network conditions. Also, this relates to a correspondingly equipped wind park and an operating method.

Abstract: A system for a wind energy installation. The wind energy installation feeds electrical power into a power supply system. A phase control device can include a power supply system fault detector, a phase angle detector, and a signal processing module. When a power supply system fault is detected, a phase error signal can be determined. A preset angle signal can be determined based on the phase error signal. The preset angle signal can be provided to a converter which can emit electrical power having a phase angle corresponding to the preset angle signal into the power supply system. Accordingly, an undesirable sudden surge in power output resulting from a phase change occurring at the end of the power supply system disturbance can be avoided.

Abstract: A wind park and operating method thereof. The wind park includes at least two wind energy systems each comprising a generator and converter for generating electrical energy and a control system, a park master designed for active and idle power control that transmits a control signal for idle power via a communications network to the wind energy systems, and a connection network feeding generated electrical energy into a grid. The wind energy system can include an idle power regulator and a supplementary regulator, the control signals of each of which are linked together. Thus, a combination of idle power and voltage regulation is achieved that combines the advantages of each. Accordingly, the wind park can have high dynamic and stability notwithstanding erratic changes in the grid.

Abstract: A converter for a wind energy installation and a method. The converter includes an inverter which drives a generator via a plurality of phases and an intermediate circuit having an intermediate-circuit voltage between an upper and a lower intermediate-circuit potential. The generator is driven with phase potentials at a variable frequency. A shift value is calculated between an extreme phase potential and one of the intermediate-circuit potentials, a separation value is determined between a middle phase potential and the closest intermediate-circuit potential, and an additional voltage is generated using the separation value as amplitude. The phase potentials are shifted through the shift value and the additional voltage is added to the middle phase potential. Accordingly, the switching elements in the converter do not need to be clocked in every second half-cycle resulting in reduced switching losses and increased current load capacity of the converter.

Abstract: A wind turbine includes a rotor having adjustable rotor blades for driving a generator and an adjusting device for the rotor blades provided with an actuator that comprises at least an excitation winding. The adjusting device includes a torque-reducing device that automatically reduces drag torque of the actuator. The torque-reducing device includes a current divider that switches the current through the excitation winding in such a manner that the current flows completely through the excitation coil when the motor is in operation and the current only partly flows through the excitation coil when coasting (slip operation). As a result, when coasting, the magnetization of the excitation winding is reduced about the adjusting device, whereby the increase of the speed torque characteristic curve can be determined, thus improving the ratio of the adjusting device when coasting.

Abstract: A method for the operation of a converter of a power-generating generator system that can be connected to an electrical AC network, and the use of the converter is provided. The converter is operated by a regulation device regulating the converter as an active audio frequency block. At least one audio frequency current of at least one specified audio frequency is detected. An AC current progression that is to be transmitted to the converter in the regulation device is determined, where at least one audio frequency current is at least partially impressed on the AC current progression. The AC current progression in the converter is generated. The AC current progression generated by the converter is then supplied to the AC network.

Abstract: A wind energy installation is provided with a generator driven by a rotor with adjustable rotor blades to produce electrical energy, with a pitch adjustment device to adjust the blades, which pitch adjustment device includes an emergency circuit with an energy store to actuate a blade actuating motor. A shunt branch is provided with a current-balancing device in parallel with the energy store, the current balancing device configured to control the current shunt branch depending on a feedback current from the blade actuating motor. A current balancing circuit is provided with which the feedback current occurring in the overrunning state is dissipated in controlled fashion via a shunt branch and therefore the electrical energy store is protected from a damaging feedback current. This prevents a damaging rise in the voltage of the electrical energy store and a rise in the motor speed of the blade actuating motor during overrunning operation.

Abstract: A wind energy installation includes a wind rotor, a double-fed asynchronous generator driven by the wind rotor, a converter provided with a first part on the generator side connected to a rotor and a second part on the network side connected to a stator of the generator, and a control device providing converter regulation. A mode selector can be switched between a normal operating mode and a reduced voltage operating mode, in which the excitation of the generator is reduced compared to the normal operating mode. The under-excitation produces an additional reactive current, thus reducing the rotor voltage. The rotor voltage can be limited even when the load is high and the network frequency or voltage is incorrect. The usable rotation speed range of the wind energy installation can be extended to provide a more powerful generator with a higher rating, without changing the converter.

Abstract: A wind energy installation, monitoring device, and method. An exemplary wind energy installation includes a rotor including at least one blade and a generator configured to be driven by the rotor to produce electrical energy. The installation also includes a pitch device configured to vary the at least one blade of the rotor. The pitch device includes a power supply unit with a battery, an actuating drive, a monitoring unit, and a load module configured to switch the actuating drive between an operating mode and a test mode. In the test mode, the actuating drive forms a preselectable defined load for the battery. Accordingly, a high and reproducible load not dependent upon environmental conditions may be applied to conduct a stress test, even during ongoing operation.

Abstract: A wind energy installation test device for defined production of grid system faults, and a method thereof. The test device can include an output configured to connect to a wind energy installation, an input configured to connect to a grid system, and a switching device for connection of an electrical disturbance component relating to a grid system parameter. An autotransformer can be used for the electrical disturbance component. The grid system in a sound state can be connected to a primary winding connection and the grid system in a disturbed state with respect to the grid system parameter can be output at a secondary winding connection.

Abstract: A wind energy installation includes a rotor, a generator driven by the rotor, and a converter for generating electrical power which is output into a power supply system via a transformer. The installation also includes an open-loop control system having an open-loop converter control unit. The open-loop control system supplies an actuating signal for a reactive component to the converter. The installation further includes a voltage measurement device arranged on the transformer. The voltage signal of the voltage measurement device is applied to an input of a state-dependent setpoint value shifter, whose output signal is applied to a limitation module for the reactive component acting on the converter. With this configuration, the installation can be better protected and the transformer can be better utilized.

Abstract: A method for controlling a converter of a wind energy installation. The converter is connected to the rotor of a doubly-fed asynchronous generator in order to feed electrical power into an electrical grid and comprises a generator-side inverter, a grid-side inverter, and at least one converter regulator for regulating and/or controlling current output from at least one of the inverters to the doubly-fed asynchronous generator and/or to the electrical grid. The method includes detecting a change in output real power, determining whether the detected change satisfies a predefined condition, and changing a nominal value of reactive power to be output in an opposite sense to a change in real power at the grid-side inverter and in a same sense as the generator-side inverter when the predefined condition is satisfied.

Abstract: A wind park includes at least two wind energy systems each comprising a generator and converter for generating electrical energy and a control system, a park master designed for active and idle power control that transmits a control signal for idle power via a communications network to the wind energy systems, and a connection network feeding generated electrical energy into a grid. The wind energy system can include an idle power regulator and a supplementary regulator, the control signals of each of which are linked together. Thus, a combination of idle power and voltage regulation is achieved that combines the advantages of each. Accordingly, the wind park can have high dynamic and stability notwithstanding erratic changes in the grid.

Abstract: A method is provided for operating a wind power plant (15-19) with a rotor-driven (25-29) electric generator (30) for delivering electric power to an electric grid (31) which provides a grid voltage in which, when excess voltage prevails in the grid (31), idle power from the wind power plant (15-19) is fed to the grid (31) in order to lower the voltage. A wind power plant is provided (15-19) with a rotor-driven electric generator (30) for delivering electric power to an electric grid (31) in which when excess voltage prevails in the grid idle power from the wind power plant (15-19) is fed to the grid (31) in order to lower the voltage. Monitoring occurs to determine whether within a predeterminable time a voltage was lowered to a predeterminable reference value and/or an idle current is delivered which is greater than or equal to a predeterminable idle current reference value.

Abstract: A wind power plant is characterized in that a measurement device (18) is provided for the determination of the load on an electric motor (13, 14), wherein the control device (16, 17) reduces the load on the motor (13, 14) by reducing the rotational speed of the rotor (11), by changing the blade angle of the at least one rotor blade (12, 12?) and/or by reducing the output of the wind power plant (10) when a preselectable first load limit of the electric motor (13, 14) is exceeded.

Abstract: A wind turbine with a rotor and a generator driven by, the rotor generates electrical power and delivers it to a power system. A control unit controlling the operation of the plant includes a reactive-power control module. The control unit includes also a determining device for a safe minimum active power. Furthermore, and a limiting device for the reactive-power control module, wherein the reactive power is limited to such a measure that the safe minimum active power is still available, taking into consideration the available power. As a result, the total current generated, apart from the active current required for the safe operation of the plant, can be fed into the power system as reactive current as backup in the case of a voltage drop.

Abstract: A wind turbine includes a rotor having adjustable rotor blades for driving a generator and an adjusting device for the rotor blades provided with an actuator that comprises at least an excitation winding. The adjusting device includes a torque-reducing device that automatically reduces drag torque of the actuator. The torque-reducing device includes a current divider that switches the current through the excitation winding in such a manner that the current flows completely through the excitation coil when the motor is in operation and the current only partly flows through the excitation coil when coasting (slip operation). As a result, when coasting, the magnetization of the excitation winding is reduced about the adjusting device, whereby the increase of the speed torque characteristic curve can be determined, thus improving the ratio of the adjusting device when coasting.