| Patent application number | Description | Published |
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| 20090001726 | Energy Supply for a Blade Adjustment Device Pertaining to a Wind Energy Installation - 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 ( | 01-01-2009 |
| 20090021014 | Wind energy installation with an extended rotation speed range - 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. | 01-22-2009 |
| 20090243296 | WIND ENERGY INSTALLATION WITH AN AUTONOMOUS ENERGY SUPPLY FOR A BLADE ADJUSTMENT DEVICE - Wind energy installation with a generator ( | 10-01-2009 |
| 20110031762 | WIND ENERGY SYSTEM HAVING A CONNECTION PROTECTION DEVICE - 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. | 02-10-2011 |
| Patent application number | Description | Published |
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| 20080252076 | Wind Power Plant Comprising a Reactive Power Module For Supporting a Power Supply System and Corresponding Method - 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. | 10-16-2008 |
| 20090322086 | DRIVE CIRCUIT AND METHOD FOR INVERTERS OF WIND ENERGY INSTALLATIONS - 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. | 12-31-2009 |
| 20100001527 | CONTROLLABLE PHASE-ANGLE CONVERTER - 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. | 01-07-2010 |
| 20100091417 | Overvoltage protective device for wind energy installations - 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. | 04-15-2010 |
| 20100148506 | ROTOR BLADE ADJUSTMENT DEVICE FOR A WIND TURBINE - 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. | 06-17-2010 |
