Abstract: An overvoltage protective device for wind energy installations is designed for connection to a connecting line having at least one inductance between a wind energy installation and a grid system. The overvoltage protective device has a controller which operates a limiting unit as a function of an overvoltage at the wind energy installation. The limiting unit comprises a spur line having an induction module and a power tapping module which is provided with a switching unit. This yields a second power strand which can accept a considerable reactive current if necessary, thus increasing the voltage drop across the inductance, as a result of which the voltage acting on the wind energy installation is reduced.

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 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 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 windpark includes at least two wind energy installations, each of which installations comprises a rotor, a generator driven by the rotor and a control device, and which are connected via connecting lines to a main line. The windpark also includes a linking point which connects the main line to a power transmission network, a parkmaster which is configured for power factor control and has communication lines for transmission of control signals to the wind energy installations, and a power-factor control section including a distributed regulator having a higher-level regulator located at the parkmaster which is configured to determine a nominal voltage in order to set a global power coefficient for the power which is emitted to the power transmission network and to emit the nominal voltage as a signal via the communication lines and lower-level regulators at the wind energy installations.

Abstract: Wind energy installation with a generator (13) which is driven by a rotor (2) with adjustable rotor blades (21), for producing electrical energy, wherein a pitch adjustment device (3) is provided for adjusting the blades, which pitch adjustment device comprises an emergency circuit (5) with an energy store (50) for actuating a blade actuating motor (55). The invention provides for a shunt branch (60) with a current-balancing device (6, 6?) to be provided in parallel with the energy store (50), wherein the current-balancing device (6, 6?) is designed so as to control the current shunt branch (60) depending on a feedback current from the blade actuating motor (55). The invention provides a current balancing circuit (6), 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 (50) is protected from a damaging feedback current.

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 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: The invention relates to a wind turbine with a rotor, a generator driven by it, which generates electrical power and delivers it to a power system, and a control unit which controls the operation of the plant and has a reactive-power control module. According to the invention, it is provided that the control unit has a determining device for a safe minimum active power. Furthermore, it comprises a limiting device for the reactive-power control module, in such a manner that the reactive power is limited to such a measure that the safe minimum active power is still available, taking into consideration the available apparent 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. The invention is also related to a corresponding method.

Abstract: A windpark includes at least two wind energy installations, each of which installations comprises a rotor, a generator driven by the rotor and a control device, and which are connected via connecting lines to a main line. The windpark also includes a linking point which connects the main line to a power transmission network, a parkmaster which is configured for power factor control and has communication lines for transmission of control signals to the wind energy installations, and a power-factor control section including a distributed regulator having a higher-level regulator located at the parkmaster which is configured to determine a nominal voltage in order to set a global power coefficient for the power which is emitted to the power transmission network and to emit the global power coefficient as a signal via the communication lines and lower-level regulators at the wind energy installations.