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EP-4544175-B1 - METHOD OF OPERATING A WIND TURBINE

EP4544175B1EP 4544175 B1EP4544175 B1EP 4544175B1EP-4544175-B1

Inventors

  • FREIBERG, Uffe Sjølund
  • GOLLNICK, BERT
  • Vives Jaume, Xavier

Dates

Publication Date
20260506
Application Date
20230828

Claims (15)

  1. A method of operating a wind turbine (100), wherein the wind turbine (100) is operable in plural different operating modes (41-46) that differ by at least one of lifetime consumption of the wind turbine and energy production by the wind turbine, wherein the method comprises: determining, in an optimization procedure, a sequence (305; 741-745) of said operating modes for a future period of time (301), wherein determining the sequence (305; 741-745) comprises estimating, for the future period of time (301) and for each of plural different sequences that include different combinations of operating modes, an optimization parameter ( op ) from at least an estimated lifetime consumption and an estimated energy production associated with the operation in the operating modes of the respective sequence, wherein the estimation of the optimization parameter ( op ) is further based on at least one estimated external parameter ( ep ); obtaining a current value for the at least one external parameter (ep); determining an actual operating mode for the wind turbine for a current point in time, wherein the determining of the actual operating mode comprises estimating an adjusted optimization parameter for each of plural different sequences of operating modes that define a different operating mode (41-47) at the current point in time and for which the optimization parameter has been estimated in the optimization procedure, wherein the adjusted optimization parameter is estimated for the respective sequence of operating modes by adjusting the optimization parameter, which has been estimated in the optimization procedure for the respective sequence, for the current value of the at least one external parameter (ep), and further comprises selecting one of the different operating modes (41-47) as the actual operating mode based on the estimated adjusted optimization parameters, wherein the optimization procedure is not repeated for determining the actual operating mode; and operating the wind turbine in the determined actual operating mode.
  2. The method according to claim 1, wherein the obtaining of a current value, the determining of the actual operating mode, and the operating of the wind turbine in the determined actual operating mode are performed repeatedly using the same optimization parameters estimated for the plural different sequences of operating modes in the optimization procedure.
  3. The method according to claim 1 or 2, wherein selecting one of the different operating modes as the actual operating mode based on the estimated adjusted optimization parameters comprises selecting the operating mode for which operation at the current point in time results in an adjusted optimization parameter that meets an optimization target, in particular for which the adjusted optimization parameter has a maximum or minimum value.
  4. The method according to any of the preceding claims, wherein estimating the adjusted optimization parameters comprises: for the different sequences (741-746) of operating modes that differ at least by their operating mode (41-47) for the current point in time, estimating the dependency (841-846) of the optimization parameter ( op ) derived in the optimization procedure for the respective sequence on the value of the at least one external parameter ( ep ), and estimating the adjusted optimization parameter for each of said sequences for the obtained current value of the at least one external parameter using the dependency.
  5. The method according to any of the preceding claims, wherein the plural different sequences of operating modes comprise plural groups, each group comprising plural different candidate sequences of operating modes, wherein the sequences within the same group comprise the same operating mode (41-46) for a current time interval (302) of the future period of time (301), wherein the sequences of different groups comprise a different operating mode for the current time interval, and wherein the optimization parameter ( op ) is estimated, in the optimization procedure, for each of the different candidate sequences within each group.
  6. The method according to claim 5, wherein determining the sequence of operating modes for the future period of time (301) comprises determining an optimal sequence (741-746) for each of the different groups by selecting a candidate sequence from the respective group for which the optimization parameter meets an optimization target, wherein the adjusted optimization parameter is estimated for each of the optimal sequences (741-746) of the groups.
  7. The method accord to claim 6, wherein for the optimal sequence (741-746) of each group, the dependency (841-846) of the optimization parameter ( op ) on the value of the at least one external parameter ( ep ) is estimated to determine the adjusted optimization parameter for the respective optimal sequence.
  8. The method according to any of the preceding claims, wherein estimating the adjusted optimization parameter comprises employing a linear dependency (841-846) or a non-linear dependency between the value of the optimization parameter and the value of the at least one external parameter.
  9. The method according to claim 7 or 8, wherein a slope or another parameter of the dependency (841-846) is determined to be dependent on an operating parameter estimated for the operating mode (41-46) at the current point in time for which the adjusted optimization parameter is estimated, wherein the operating parameter is preferably an energy production estimated for the respective operating mode (41-46).
  10. The method according to any of the preceding claims, wherein estimating the adjusted optimization parameter for a respective sequence of operating modes comprises: obtaining the optimization parameter estimated in the optimization procedure for the sequence (741-746) that includes the respective operating mode (41-46) for a current time interval, the estimation being based on the at least one estimated external parameter for the current time interval; and determining the adjusted optimization parameter by adjusting the obtained optimization parameter using the current value of the at least one external parameter and an estimated dependency between the optimization parameter and the at least one external parameter for the current time interval.
  11. The method according to claim 10, further comprising estimating the energy production of the wind turbine (100) within the current time interval when operating in the respective operating mode (41-46), and estimating the dependency between the optimization parameter ( op ) and the at least one external parameter (ep) from at least the energy production in the current time interval.
  12. The method according to any of the preceding claims, wherein the at least one external parameter ( ep ) is at least one of wind speed and electricity price.
  13. A control system for operating a wind turbine, wherein the control system (10) is configured to operate the wind turbine (100) in plural different operating modes (41-46) that differ by at least one of lifetime consumption of the wind turbine (100) and energy production by the wind turbine (100), wherein the control system (10) is configured to perform the method according to any of the preceding claims.
  14. A wind turbine, wherein the wind turbine (100) comprises a control system (10) according to claim 13, wherein the control system (10) is configured to control the operation of the wind turbine (100) in plural different operating modes (41-46).
  15. A computer program for controlling the operation of a wind turbine (100), wherein the computer program comprises control instructions which, when executed by a processing unit (11) of a control system (10) that controls the operation of the wind turbine (100), cause the processing unit (11) to perform the method of any one of claims 1 to 12.

Description

FIELD OF THE INVENTION The present invention relates to a method of operating a wind turbine, wherein the wind turbine is operable in plural different operating modes. The invention also relates to a control system and a wind turbine comprising such control system, and further to a computer program. BACKGROUND The use of wind energy is proliferating. Wind turbines are being installed at different locations throughout the world and are thus exposed to different environmental conditions. Wind turbines must withstand considerable wind forces that act on the rotor, the nacelle and the tower of the wind turbine. During their lifetime, the structural components of the wind turbine are exposed to a number of load cycles that can eventually lead to failure of a component. Wind turbines can often be operated in different operating modes, wherein some modes drive the wind turbine more aggressively (generally resulting in higher loads and higher energy production), while other modes drive the wind turbine less aggressively (generally resulting in lower loads and lower energy production). The wind turbine may further be exposed to varying environmental conditions, such as wind speeds, which may in some situations result in a reduced energy production, and may in other situations result in high loads acting on the wind turbine and thus in a high lifetime consumption. It is therefore difficult for an operator to determine the best way in which the wind turbine is to be operated. Some optimization methods are known which optimize the wind turbine operation to achieve an optimization target, such as a maximization of the energy production, a minimization of lifetime consumption, a maximization of the alignment between energy production and demand, and a maximization of revenue. An example of such optimization is described in the document WO 2021/214152 A1. Although this method achieves a good optimization for many situations, there might be some situations in which the determined operating scheme for the wind turbine can still be improved to achieve a better result, e.g. a higher energy production or return, a longer lifetime, or making better use of the wind turbine over a design lifetime. Further relevant background art is disclosed in EP 3 964 707 A1 and WO 2014/187461 A1. SUMMARY There is accordingly a need to improve the operation of a wind turbine, and in particular to operate the wind turbine in such way that an operation target is better achieved, such as improved energy production or revenue. This need is met by the features of the independent claims. The dependent claims describe embodiments of the invention. In an embodiment of the present invention, a method of operating a wind turbine is provided, wherein the wind turbine is operable in plural different operating modes that differ by at least one of lifetime consumption of the wind turbine and energy production by the wind turbine. The method comprises determining, in an optimization procedure, a sequence (one or more) of the operating modes for a future period of time. Determining the sequence comprises estimating, for the future period of time and for each of plural different sequences that include different combinations of operating modes (e.g. candidate sequences), an optimization parameter based at least on an estimated energy production associated with the operation of the wind turbine in the operating modes of the respective sequence. Such optimization procedure may also be termed long-term optimization, as it may estimate the optimization parameter for a longer period of time, e.g. until an estimated end of life of the wind turbine. The method may further comprise obtaining a current value of at least one parameter, wherein the at least one parameter is an operating parameter of the wind turbine and/or an external parameter, and determining an actual operating mode for the wind turbine for a current point in time, wherein the determining of the actual operating mode is based at least on the determined sequence of operating modes and the obtained current value of the at least one parameter. Such selection of the actual operating mode may be termed short-term optimization, as it may determine the actual operating mode for a shorter period of time. Further, the wind turbine is operated in the determined actual operating mode. The actual operating mode may be allowed to differ from the operating mode prescribed by the determined sequence of operating modes for the current point in time, in particular to differ from a determined sequence for which the estimated optimization parameter meets an optimization target (optimal sequence). Several benefits may be achieved by such method. The determined sequence of operating modes may be or may include a sequence for which the optimization parameter is at its optimum, e.g. at a maximum or minimum, depending on the kind of optimization parameter. An example is a sequence of operating modes that maximizes energy produ