Blade monitoring by actively promoting blade vibrations
AssigneeVestas Wind Systems A/S
InventorsAnders Skafte, Gustavo Oliveira Violato, Fabio Caponetti
Life of this patent
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Abstract
Techniques are provided for monitoring blades of a wind turbine by actively promoting blade vibrations by imposing a pitch actuation signal. A method of operating a wind turbine is disclosed where for each blade of a wind turbine, vibrations of the blade are actively promoted by imposing a pitch actuation signal to the pitch actuator, and at least one parameter relating to the blade vibration is determined.
Claims17
A method of operating a wind turbine, the wind turbine comprising a rotor with at least one pitch adjustable rotor blade, where the at least one pitch adjustable rotor blade comprises a pitch actuator for adjusting a pitch angle, the method comprising:
- applying a pitch actuation signal to the pitch actuator, the pitch actuation signal being conditioned to promote active blade vibration;
- and
- determining at least one parameter relating to the active blade vibration, wherein promoting the active blade vibration is conducted by:
- receiving an edgewise load signal for the at least one pitch adjustable rotor blade, the edgewise load signal being measured in a rotating reference frame;
- applying an m-blade coordinate transformation to the edgewise load signal to transform the edgewise load signal to a whirling reference frame along a first and a second reference direction;
- selecting a signal component of either the first or the second reference direction to obtain a selected signal component;
- filtering the selected signal component at either a backward whirling frequency or a forward whirling frequency to obtain a filtered signal component;
- applying an inverse m-blade coordinate transformation to the filtered signal component to obtain a pitch modification signal;
- and
- setting the pitch modification signal the pitch actuation signal for the at least one pitch adjustable rotor blade to actively promote blade vibrations.
A control system for a wind turbine, the wind turbine comprising a rotor with at least one pitch adjustable rotor blade, where the at least one pitch adjustable rotor blade comprises a pitch actuator for adjusting a pitch angle;
- the control system comprising:
- a pitch actuation unit being configured to actively promote blade vibration in response to a pitch actuation signal being applied to the pitch actuator;
- and
- a control module being configured to determine at least one parameter relating to the active blade vibration, wherein promoting the active blade vibration is conducted by:
- receiving an edgewise load signal for the at least one pitch adjustable rotor blade, the edgewise load signal being measured in a rotating reference frame;
- applying an m-blade coordinate transformation to the edgewise load signal to transform the edgewise load signal to a whirling reference frame along a first and a second reference direction;
- selecting p signal component of either the first or the second reference direction to obtain a selected signal component;
- filtering the selected signal component at either a backward whirling frequency or a forward whirling frequency to obtain a filtered signal component;
- applying an inverse m-blade coordinate transformation to the filtered signal component to obtain a pitch modification signal;
- and
- setting the pitch modification signal the pitch actuation signal for the at least one pitch adjustable rotor blade to actively promote blade vibrations.
A computer program product comprising a non-transitory computer readable medium storing software code which, when executed on a data processing system, performs an operation controlling a wind turbine, the wind turbine comprising a rotor with at least one pitch adjustable rotor blade, where the at least one pitch adjustable rotor blade comprises a pitch actuator for adjusting a pitch angle;
- the operation comprising:
- applying a pitch actuation signal to the pitch actuator, the pitch actuation signal being conditioned to actively promote blade vibration on the at least one pitch adjustable rotor blade;
- and
- determining at least one parameter relating to the active blade vibration, wherein promoting the active blade vibration is conducted by:
- receiving an edgewise load signal for the at least one pitch adjustable rotor blade, the edgewise load signal being measured in a rotating reference frame;
- applying an m-blade coordinate transformation to the edgewise load signal to transform the edgewise load signal to a whirling reference frame along a first and a second reference direction;
- selecting a signal component of either the first or the second reference direction to obtain a selected signal component;
- filtering the selected signal component at either a backward whirling frequency or a forward whirling frequency to obtain a filtered signal component;
- applying an inverse m-blade coordinate transformation to the filtered signal component to obtain a pitch modification signal;
- and
- setting the pitch modification signal the pitch actuation signal for the at least one pitch adjustable rotor blade to actively promote blade vibrations.
Dependencies are inferred from the claim text.