Wind turbine generator system and operation control method therefor

An operation control method for a wind turbine generator system having a plurality of wind turbines, a central controller for providing control commands to the wind turbines, and outputs of the wind turbines being supplied to a utility grid via a common interconnection node, the operation control method comprising:

• determining if the plurality of wind turbines includes both variable-speed wind turbines and fixed-speed wind turbines, and when the plurality of wind turbines includes both variable-speed wind turbines and fixed-speed wind turbines, calculating the overall reactive power of the fixed-speed wind turbines at the interconnection node;
• calculating the difference between the calculated overall reactive power and a predetermined reactive-power command value for the interconnection node;
• correcting the predetermined reactive-power command value using the calculated difference;
• and
• determining reactive-power command values corresponding to the variable-speed wind turbines based on the corrected predetermined reactive-power command value,
• wherein the determined reactive-power command values of at least two of the variable-speed wind turbines are different from each other.

A wind turbine generator system comprising:

• a plurality of individual wind turbines,
• a central controller for providing control commands to the individual wind turbines, and
• a common interconnection node for supplying output powers of the individual wind turbines being supplied to a utility grid,
• wherein the central controller is configured to determine reactive-power command values corresponding to the individual wind turbines by correcting a predetermined reactive-power command value for the interconnection node using reactive power correction levels set for the individual wind turbines,
• wherein the determined reactive-power command values of at least two of the plurality of the individual wind turbines are different from each other.

A wind turbine generator system comprising:

• a plurality of individual wind turbines,
• a central controller for providing control commands to the individual wind turbines, and
• a common interconnection node for supplying outputs of the individual wind turbines to a utility grid, wherein
• the plurality of individual wind turbines includes both variable-speed wind turbines and fixed-speed wind turbines, and
• the central controller is configured to:
• calculate the overall reactive power of the fixed-speed wind turbines at the interconnection node;
• calculate the difference between the calculated overall reactive power and a predetermined reactive-power command value for the interconnection node;
• correct the predetermined reactive-power command value using the calculated difference;
• and
• determine reactive-power command values corresponding to the variable-speed wind turbines based on the corrected predetermined reactive-power command value,
• wherein the determined reactive-power command values of at least two of the variable-speed wind turbines are different from each other.