Torque limiter based on current torque value
AssigneeVestas Wind Systems A/S
InventorsJohn Schwensen, Sara Siniscalchi Minna, Tobias Gybel Hovgaard
Life of this patent
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Abstract
Techniques are provided for control of a wind turbine where a torque limit is set based on a control signal. A current torque value of a rotor of the wind turbine is determined and compared to an upper torque limit value and the control signal is modified if the current torque value is larger than the upper torque limit value. The upper torque limit value is based on a lower envelope signal which tracks the current torque value if the current torque value is lower than or equal to the previous lower envelope value and is set as a rising signal if the current torque value is higher than the previous lower envelope value. The upper torque limit is set to be a first amount higher than the lower envelope signal.
Claims20
A method of controlling a wind turbine, comprising:
- determining a control signal for controlling the wind turbine;
- determining a current torque value of a rotor of the wind turbine and comparing the current torque value to an upper torque limit value, and when the current torque value is larger than the upper torque limit value, modifying the control signal so that a resulting torque value of the rotor is reduced, wherein the current torque value and previous torque values are included in a torque signal;
- wherein the upper torque limit value is based on a lower envelope signal comprising previous lower envelope values and a current lower envelope value, the lower envelope signal tracks the current torque value when the current torque value is lower than or equal to a previous lower envelope value of the previous lower envelope values and is set as a rising signal when the current torque value is higher than the previous lower envelope value, and wherein the upper torque limit value is set to be a first amount higher than the lower envelope signal;
- and
- controlling the wind turbine based on the control signal so that the resulting torque value of the rotor is changed.
A controller for controlling a wind turbine, the controller comprising:
- a control unit arranged for determining a control signal for controlling the wind turbine;
- a torque limit unit arranged for determining a current torque value of a rotor of the wind turbine and compare the current torque value to an upper torque limit value, when the current torque value is larger than the upper torque limit value, to instruct the control unit to modify the control signal so that a resulting torque value of the rotor is reduced, wherein the current torque value and previous torque values are included in a torque signal;
- a torque evaluation unit arranged for determining a lower envelope signal comprising previous lower envelope values and a current lower envelope value, wherein the upper torque limit value is based on the lower envelope signal, the lower envelope signal tracks the current torque value when the current torque value is lower than or equal to a previous lower envelope value of the previous lower envelope values and is set as a rising signal when the current torque value is higher than the previous lower envelope value, and wherein the upper torque limit value is set to be a first amount higher than the lower envelope signal;
- and
- wherein the controller is configured to control the wind turbine based on the control signal so that the resulting torque value of the rotor is changed.
A wind turbine, comprising:
- a tower;
- a nacelle mounted rotatably on the tower;
- one or more pitchable wind turbine blades mounted rotatably on the nacelle via a hub;
- and
- a controller, comprising:
- a control unit arranged for determining a control signal for controlling the wind turbine;
- a torque limit unit arranged for determining a current torque value of a rotor of the wind turbine and compare the current torque value to an upper torque limit value, and when the current torque value is larger than the upper torque limit value, to instruct the control unit to modify the control signal so that a resulting torque value of the rotor is reduced, wherein the current torque value and previous torque values are included in a torque signal;
- a torque evaluation unit arranged for determining a lower envelope signal comprising previous lower envelope values and a current lower envelope value, wherein the upper torque limit value is based on the lower envelope signal, the lower envelope signal tracks the current torque value when the current torque value is lower than or equal to a previous lower envelope value of the previous lower envelope values and is set as a rising signal when the current torque value is higher than the previous lower envelope value, and wherein the upper torque limit value is set to be a first amount higher than the lower envelope signal;
- and
- wherein the controller is configured to control the wind turbine based on the control signal so that the resulting torque value of the rotor is changed.
Dependencies are inferred from the claim text.