Method of calibrating a reference of a wind turbine

A computer program product comprising software code adapted to calibrate a reference of a wind turbine when executed on a data processing system, the computer program product being adapted to perform an operation for calibrating the reference of the wind turbine, comprising:

• monitoring performance of the wind turbine over a calibration period to generate performance data, wherein the calibration period comprises a series of sub-periods;
• and
• for each sub-period:
• determining a sub-period value on the basis of the performance data generated during that sub-period;
• determining an operational condition of the wind turbine;
• and
• determining when the operational condition is a pre-defined operational condition,
• for an operational condition being a pre-defined operational condition:
• updating the reference with the sub-period value thereby calibrating the reference;
• for all operational conditions:
• comparing the sub-period value with the reference;
• and
• updating the reference with the sub-period value when the comparison shows that a performance of the wind turbine indicated by the sub-period value is better than a performance of the wind turbine indicated by the reference thereby calibrating the reference, and
• wherein the reference is set on the basis of a running average of the performance data, the running average being determined on the basis of a sample count, and wherein the method further comprises resetting the sample count when the comparison shows that the performance of the wind turbine indicated by the sub-period value is larger than the performance of the wind turbine indicated by the reference.

A method of detecting a state of a wind turbine, the method comprising:

• calibrating a reference of the wind turbine by:
• monitoring performance of the wind turbine over a calibration period to generate performance data, wherein the calibration period comprises a series of sub-periods;
• and
• for each sub-period:
• determining a sub-period value on the basis of the performance data generated during that sub-period;
• determining an operational condition of the wind turbine, and
• determining when the operational condition is a pre-defined operational condition,
• for an operational condition being a pre-defined operational condition:
• updating the reference with the sub-period value thereby calibrating the reference;
• for all operational conditions:
• comparing the sub-period value with the reference, and
• updating the reference with the sub-period value when the comparison shows that a performance of the wind turbine indicated by the sub-period value is better than a performance of the wind turbine indicated by the reference thereby calibrating the reference;
• and
• during the calibration period, detecting a state of the wind turbine by comparing the performance data with the reference, and
• wherein, at the start of the calibration period, the method comprises setting the reference to a degraded value according to a degraded power curve that is lower than a reference power curve.

An apparatus, comprising:

• a performance sensor configured to monitor a performance of a wind turbine to generate performance data;
• and
• a calibration system configured to calibrate a reference by performing an operation, comprising:
• monitoring performance of the wind turbine over a calibration period to generate performance data, wherein the calibration period comprises a series of sub-periods;
• and
• for each sub-period:
• determining a sub-period value on the basis of the performance data generated during that sub-period;
• determining an operational condition of the wind turbine, and
• determining when the operational condition is a pre-defined operational condition, for an operational condition being a pre-defined operational condition:
• updating the reference with the sub-period value thereby calibrating the reference;
• for all operational conditions:
• comparing the sub-period value with the reference, and
• updating the reference with the sub-period value when the comparison shows that a performance of the wind turbine indicated by the sub-period value is better than a performance of the wind turbine indicated by the reference thereby calibrating the reference, and
• wherein the reference is set on the basis of a running average of the performance data, the running average being determined on the basis of a sample count, and wherein the operation further comprises resetting the sample count when the comparison shows that the performance of the wind turbine indicated by the sub-period value is larger than the performance of the wind turbine indicated by the reference.