How can wind turbine be used to frequency control in a grid?
It seems likely that the quoted statement is related to supplying reactive volt-amperes to the grid. Only wound-field synchronous generators can supply reactive volt-amperes. All other generating sources need to have capacitors to supply reactive volt-amperes. Grid operators tend to accept connection with supply their &quot;fair share&quot; of the reactive volt-ampere load connected to the grid. That means that wind turbines and other sources that are not wound-field synchronous generators would likely have capacitor banks connected to the grid either directly or through a grid-tied inverter. A grid-tied inverter for a wind turbine could supply reactive volt-amperes without the turbine operating. They would not really be operating as &quot;frequency regulators,&quot; but they would prevent the frequency from varying due to the reactive volt-ampere demand on the grid exceeding the supply capacity of other connected generating sources.
Other questions here answer questions about reactive volt-amperes they will have the [power-factor-correction] tag. For example: Power factor correction of predominantly inductive load component with capacitor