Low-Wind Operation of Clustered Doubly Fed Induction Generator Wind Turbines

A method for operating a cluster transformer, the cluster transformer operably coupled to one or more doubly fed induction generator (DFIG) modules, each DFIG module comprising a DFIG and a power conversion system, the cluster transformer configured to convert power from the one or more DFIG modules into a power suitable for application to an electrical grid, the method comprising:

• operating the cluster transformer in a normal wind mode;
• determining, by a control device, a first wind parameter;
• determining, by the control device, whether the first wind parameter is less than a threshold;
• and
• when the first wind parameter is less than the threshold, controlling, by the control device, the cluster transformer into a low-wind operation mode.

A wind farm, comprising:

• a plurality of wind turbine clusters;
• and
• a wind farm control device;
• wherein each wind turbine cluster comprises:
• a plurality of doubly fed induction generator (DFIG) modules;
• and
• a cluster transformer operably coupled to the plurality of DFIG modules;
• wherein each DFIG module comprises:
• a DFIG comprising a rotor and a stator, the rotor configured to generate AC power at a first voltage and the stator configured to generate AC power at a second voltage;
• and
• a power conversion system operably coupled to the rotor, the power conversion system configured to convert power at the first voltage to power at the second voltage;
• wherein each cluster transformer is configured to convert power at the second voltage from the plurality of DFIG modules in the wind turbine cluster to power suitable for application to a grid;
• and
• wherein the wind farm control device is configured to control operation of the cluster transformer in each wind turbine cluster based at least in part on a measured or forecasted wind parameter.