Control system having local and central controllers for wind turbine system having multiple rotors

A method of operating a wind turbine system comprising a plurality of wind turbines mounted to a common support structure, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor, wherein the method comprises:

• using each local control module of a plurality of local control modules:
• monitoring operation of a respective wind turbine of the plurality of wind turbines;
• and
• issuing local control commands to the respective wind turbine according to one or more local control objectives specific to the respective wind turbine:
• monitoring rotor speeds of a first wind turbine and a second wind turbine of the plurality of wind turbines;
• detecting or predicting a synchronization of the rotor speeds;
• determining, according to one or more supervisory control objectives applied to the wind turbines, central control commands that account for one or both of structural interactions and aerodynamic interactions between at least two wind turbines of the plurality of wind turbines, wherein determining the central control commands comprises determining a first central control command for the first wind turbine to cause the rotor speeds to become, or to remain, unsynchronized;
• and
• providing the central control commands to the plurality of local control modules.

A wind turbine system comprising:

• a plurality of wind turbines mounted to a common support structure, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor;
• a plurality of local control modules, wherein each of the plurality of local control modules is operable to:
• monitor the operation of a respective wind turbine of the plurality of wind turbines;
• and
• issue local control commands to the respective wind turbine according to one or more local control objectives specific to the respective wind turbine;
• and
• a central control module configured to:
• monitor the operation of the wind turbine system, wherein monitoring the operation of the wind turbine system comprises:
• detecting an icing condition of a rotor blade of a first wind turbine of the plurality of wind turbines;
• determine, according to one or more supervisory control objectives applied to the plurality of wind turbines, central control commands that account for one or both of structural interactions and aerodynamic interactions between at least two of the plurality of wind turbines, wherein determining the central control commands comprises determining a first central control command to shut down at least the first wind turbine;
• and
• provide the central control commands to the plurality of local control modules.

A wind turbine system comprising:

• a plurality of wind turbines mounted to a common support structure, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor;
• a plurality of local control modules, wherein each of the plurality of local control modules is operable to:
• monitor the operation of a respective wind turbine of the plurality of wind turbines;
• and
• issue local control commands to the respective wind turbine according to one or more local control objectives specific to the respective wind turbine;
• and
• a central control module configured to:
• monitor the operation of the wind turbine system, wherein monitoring the operation of the wind turbine system comprises:
• detecting asymmetric loading of the plurality of wind turbines, wherein a first wind turbine of the plurality of wind turbines is loaded more heavily than a second wind turbine of the plurality of wind turbines;
• determine, according to one or more supervisory control objectives applied to the plurality of wind turbines, central control commands that account for one or both of structural interactions and aerodynamic interactions between at least two of the plurality of wind turbines, wherein determining the central control commands comprises determining a first central control command to derate at least the first wind turbine;
• and
• provide the central control commands to the plurality of local control modules.

A wind turbine system comprising:

• a plurality of wind turbines mounted to a common support structure, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor;
• a plurality of local control modules, wherein each of the plurality of local control modules is operable to:
• monitor the operation of a respective wind turbine of the plurality of wind turbines;
• and
• issue local control commands to the respective wind turbine according to one or more local control objectives specific to the respective wind turbine;
• and
• a central control module configured to:
• monitor the operation of the wind turbine system, wherein monitoring the operation of the wind turbine system comprises:
• detecting a thrust difference between a first wind turbine and a second wind turbine that are mounted on a support arm arrangement mounted on the common support structure, wherein the thrust difference results in a yaw loading on the common support structure;
• determine, according to one or more supervisory control objectives applied to the plurality of wind turbines, central control commands that account for one or both of structural interactions and aerodynamic interactions between at least two of the plurality of wind turbines, wherein determining the central control commands comprises determining a first central control command for the first wind turbine to counteract the yaw loading;
• and
• provide the central control commands to the plurality of local control modules.