Thrust balance control of a multirotor wind turbine based on constraints

Patent metadata

Field	Value
Publication number	US-11384730-B2
Application number	US-201816956952-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Dec 20, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A method for controlling a multirotor wind turbine is disclosed. A first operational state of each of the energy generating units of the wind turbine is obtained. A difference in thrust acting on at least two of the energy generating units is detected. At least one constraint parameter of the set of operational constraints is adjusted in accordance with prevailing operating conditions and in accordance with the detected difference in thrust, and a new operational state for at least one of the energy generating units is derived, based on the at least one adjusted constraint parameter, the new operational state(s) counteracting the detected difference in thrust. Finally, the wind turbine is controlled in accordance with the new operational states for the energy generating units.

First claim

The invention claimed is:

1. A method for controlling a wind turbine having a plurality of energy generating units mounted on a support structure, each of the plurality of energy generating units having a rotor comprising a set of wind turbine blades, the method comprising:
while each energy generating unit of the plurality of energy generating units operates in a respective first operational state of a plurality of predefined operational states:
applying a respective first set of operational constraints defining limits for one or more operational parameters of the respective energy generating unit;
detecting a difference in thrust acting on at least two energy generating units of the plurality of energy generating units;
adjusting, for at least one energy generating unit of the plurality of energy generating units, at least one operational constraint of the respective first set of operational constraints in accordance with prevailing operating conditions and with the difference in thrust, wherein adjusting the at least one operational constraint allows the at least one energy generating unit to temporarily operate outside the limits for the one or more operational parameters, thereby increasing loads on the support structure of the wind turbine; and
selecting, based on the adjusted at least one operational constraint, a respective second operational state of the plurality of predefined operational states for the at least one energy generating unit; and

operating the at least one energy generating unit in the respective second operational state to thereby counteract the difference in thrust.

2. The method of claim 1 , wherein the adjusting at least one operational constraint comprises:
adjusting a load constraint relating to the at least one energy generating unit.

3. The method of claim 1 , wherein the adjusting at least one operational constraint comprises:
adjusting a load constraint relating to the support structure.

4. The method of claim 1 , wherein the adjusting at least one operational constraint comprises:
adjusting a power production constraint relating to the at least one energy generating unit.

5. The method of claim 1 , wherein the adjusting at least one operational constraint comprises:
adjusting a range or a setpoint for the at least one operational constraint.

6. The method of claim 1 , wherein the detecting the difference in thrust comprises:
detecting that operation of one of the at least two energy generating units has stopped.

7. The method of claim 1 , wherein the detecting the difference in thrust comprises:
detecting a difference in wind conditions at the at least two energy generating units.

8. The method of claim 1 , wherein the detecting the difference in thrust comprises:
detecting a difference in operational state of the at least two energy generating units.

9. The method of claim 8 , wherein detecting the difference in the operational state comprises:
detecting a difference in at least one of pitch angle or rotor speed.

10. The method of claim 1 ,
wherein the support structure comprises:
a main tower part extending along a substantially vertical direction;
a yawing mechanism; and
at least two arms connected to the main tower part via the yawing mechanism, each arm extending away from the main tower part along a direction having a horizontal component, and

wherein detecting the difference in thrust comprises detecting a torque on the yawing mechanism.

11. The method of claim 1 , wherein the selecting the respective second operational state comprises:
specifying that a first energy generating unit of the at least one energy generating unit shall operate in motor mode.

12. The method of claim 1 , wherein the selecting the respective second operational state comprises:
adjusting at least one yaw setting of the wind turbine.

13. The method of claim 1 , wherein the selecting the respective second operational state comprises:
shutting down a first energy generating unit of the at least one energy generating unit.

14. The method of claim 1 , further comprising:
performing, based on the adjusted at least one operational constraint and the difference in thrust, an optimization calculation for a total power production of the wind turbine,
wherein the selecting the respective second operational state is further based on the optimization calculation.

15. The method of claim 14 , wherein performing the optimization calculation is performed using a model predictive control (MPC) algorithm.

16. The method of claim 14 , wherein the performing the optimization calculation comprises consulting a database.

17. A wind turbine comprising:
a support structure;
a plurality of energy generating units mounted on the support structure, each of the plurality of energy generating units comprising:
a rotor; and
a set of wind turbine blades disposed on the rotor; and

a control system confirmed to perform an operation comprising:
while each energy generating unit of the plurality of energy generating units operates in a respective first operational state of a plurality of predefined operational states:
applying a respective first set of operational constraints defining limits for one or more operational parameters of the respective energy generating unit;
detecting a difference in thrust acting on at least two energy generating units of the plurality of energy generating units;
adjusting, for at least one energy generating unit of the plurality of energy generating units, at least one operational constraint of the respective first set of operational constraints in accordance with prevailing operating conditions and with the difference in thrust, wherein adjusting the at least one operational constraint allows the at least one energy generating unit to temporarily operation outside the limits for the one or more operational parameters, thereby increasing loads on the support structure of the wind turbine; and
selecting, based on the adjusted at least one operational constraint, a respective second operational state of the plurality of predefined operational states for the at least one energy generating unit; and

operating the at least one energy generating unit in the respective second operational state to thereby counteract the difference in thrust.

18. The wind turbine of claim 17 , wherein the adjusting at least one operational constraint comprises:
adjusting a load constraint relating to the at least one energy generating unit.

19. The wind turbine of claim 17 , wherein the adjusting at least one operational constraint comprises:
adjusting a load constraint relating to the support structure.

20. The wind turbine of claim 17 , wherein the adjusting at least one operational constraint comprises:
adjusting a power production constraint relating to the at least one energy generating unit.

Assignees

• Vestas Wind Sys As

Inventors

• Dalsgaard Søren
• Neubauer Jesper Lykkegaard
• Sørensen Kim Hylling
• Brøchner Jacob
• Miranda Erik Carl Lehnskov
• Bøttcher Peter
• Neto Julio Xavier Vianna
• Petersen Torben

Classifications

• F05B2240/912

  on a tower · CPC title

• F03D9/25

  the apparatus being an electrical generator (F03D9/22 takes precedence) · CPC title

• F03D7/045

  with model-based controls · CPC title

• F05B2270/404

  active, predictive, or anticipative · CPC title

• F05B2270/327

  Rotor or generator speeds · CPC title