Abstract:
A wind turbine having a rotor, a generator driven by the rotor, a converter, a control device having an input for a control signal for reactive power output and a controller for the converter, the controller determining a reactive power target value for the wind turbine and correcting the output reactive power in dependence on the voltage present at the wind turbine, and an additional module for the controller having separate small and large signal paths and interacting with the controller such that the small signal path has an additional storage element in comparison with the large signal path, which additional storage element stores state values of the small signal path for the past. Thus, small voltage changes can be reacted to more slowly and while taking into account past values, whereas large changes can be reacted to quickly, in particular in the event of a network short circuit.
Abstract:
Wind farm comprising a farm master (1) and a plurality of wind energy installations (4). The farm master (1) has a controller (15) with an input for a control parameter for power supplied to a grid and transmits desired value specifications to a local controller (5) of the wind energy installations (4). According to the invention, the local controller (5) has dual structure and comprises a desired value channel (6), to which the desired value specification is applied by the farm master (1) and which is designed to output a stationary reactive power desired value, and a responsive channel (7) comprising an autonomous controller (75), to which no desired value specification is applied by the farm master (1) and to which an actual voltage of the particular wind energy installation (4) is applied via a washout filter (71). The autonomous controller (75) with the washout filter (71) enables a fast and dependent response to transient disturbances, in particular voltage spikes and voltage dips as a result of a short circuit. The individual wind energy installation and the wind farm as a whole therefore gain a behaviour which is identical to a synchronous generator and is very favourable for grid stability in the event of voltage disturbances.
Abstract:
Wind farm comprising a farm master and a plurality of wind energy installations. The farm master has a controller with an input for a control parameter for power supplied to a grid and transmits desired value specifications to a local controller of the wind energy installations. The local controller has a dual structure and comprises a desired value channel, to which the desired value specification is applied by the farm master and which is designed to output a stationary reactive power desired value, and a responsive channel comprising an autonomous controller, to which no desired value specification is applied by the farm master and to which an actual voltage of the particular wind energy installation is applied via a washout filter. The autonomous controller with the washout filter enables a fast and dependent response to transient disturbances (e.g., voltage spikes and voltage dips as a result of a short circuit).
Abstract:
The invention relates to a method for controlling the electrical moment of a wind turbine by closed-loop control in the event of a grid fault. A fall in voltage that is outside the limits of normal operation is discovered. A moment closed-loop controller which determines a target value for the electrical moment of the wind turbine, is operated. A moment ramp is initialized. The target value of the moment closed-loop controller is compared with the moment ramp and the lesser value is selected as a moment setpoint value. The electrical moment of the wind turbine is set on the basis of the moment setpoint value. The invention additionally relates to a wind turbine suitable for implementing the method. The invention makes it possible, on the one hand, to achieve a rapid restoration of the power after the end of the grid fault, while, on the other hand, the loads for the wind turbine are kept within limits.
Abstract:
The invention relates to a wind turbine having a rotor (12), a generator (14) driven by the rotor, a converter (15), and a control device (167), which has an input for a control signal for reactive power output and a controller (72) for the converter (15). The controller (72) determines a reactive power target value for the wind turbine and corrects the output reactive power in dependence on the voltage present at the wind turbine. The invention provides for an additional module (8) for the controller (72), which additional module has separate small and large signal paths (81, 82) and interacts with the controller (72) in such a way that the small signal path (81) has an additional storage element (83) in comparison with the large signal path (82), which additional storage element stores state values of the small signal path (81) for the past. Thus, small voltage changes can be reacted to more slowly and while taking into account past values, whereas large changes can be reacted to quickly, in particular in the event of a network short circuit.