Wind energy system having a connection protection device
View Patent ↗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.
1. A wind energy installation comprising:
a rotor;
a generator driven by the rotor and having a converter configured to generate electrical power which is output into a power supply system via a transformer;
an open-loop control system comprising an open-loop converter control unit, the open-loop control system supplying an actuating signal for a reactive component to the converter; and
a voltage measurement device arranged on the transformer, a voltage signal of the voltage measurement device being applied to an input of a state-dependent setpoint value shifter configured to shift the reactive component in the event of an overvoltage toward an underexcited status and in the event of an undervoltage toward an overexcited status, the output signal of the setpoint value shifter being applied to a limitation module for the reactive component acting on the converter, the limitation module limiting the reactive component actuating signal supplied by the open-loop control system.
2. The wind energy installation of claim 1 , wherein the setpoint value shifter interacts with a load shifting module, which acts on the open-loop control system in the event of an undervoltage or overvoltage in such a way that the active portion of the output power is reduced in favor of the reactive portion.
3. The wind energy installation of claim 1 , comprising a temperature sensor for a core of the transformer, the signal from the temperature sensor being applied, as a state signal, to an input of the setpoint value shifter.
4. The wind energy installation of claim 1 , wherein the open-loop control system has a monitoring module comprising a second setpoint value shifter identical to the state-dependent setpoint value shifter.
5. The wind energy installation of claim 1 , wherein the open-loop control system comprises an isolating module with a variable limit value which acts on a system protection relay at the transformer and whose limit value is determined by the output reactive power.
6. The wind energy installation of claim 1 , wherein the setpoint value shifter interacts with a section model of the transformer, to which the voltage on one side of the transformer is applied in order to determine the voltage on the other side of the transformer.
7. The wind energy installation of claim 6 , wherein the section model is configured for corresponding reactive component determination.
8. The wind energy installation of claim 1 , wherein the setpoint value shifter comprises a PI controller.
9. The wind energy installation of claim 8 , wherein the PI controller determines a correction value for the reactive component from a voltage difference with respect to a limit value.
10. The wind energy installation of claim 1 , wherein the setpoint value shifter comprises an open-loop control element.
11. The wind energy installation of claim 10 , wherein the open-loop control element determines a reactive power correction value from applied signals for voltage and reactive power.
12. The wind energy installation of claim 10 , wherein the open-loop control element is a two-dimensional characteristic element with monotonically falling characteristics.
13. The wind energy installation of claim 10 , wherein the open-loop control element has a setpoint value matrix.
14. The wind energy installation of claim 8 , comprising a two-loop structure with one loop for overvoltage and one for undervoltage.
15. The wind energy installation of claim 8 , comprising a switchover device which enables short-term operation with extended limit values.
16. The wind energy installation of claim 1 , wherein the setpoint value shifter acts directly on the converter.
17. A method for operating a wind energy installation including a rotor, a generator driven by the rotor and having a converter configured to generate electrical power which is output into a power supply system via a transformer, and an open-loop control system comprising an open-loop converter control unit with adjustment of an actuating signal for a reactive component of the output power, comprising:
measuring a voltage across the transformer;
determining a correction signal for the degree of reactive power using a state-dependent setpoint value shifter configured to shift the reactive component in the event of an overvoltage toward an underexcited status and in the event of an undervoltage toward an overexcited status; and
using the shifted signal to limit the actuating signal of the reactive component.