Combined active and reactive power control in an operation of a wind farm

The present disclosure relates to a method and system for controlling an operation of a wind farm connected to a grid, the wind farm comprising a plurality of wind turbines, each wind turbine having a local controller, the method comprising the steps of: minimizing a central voltage deviation in a point of connection between the grid and the wind farm compared to a reference voltage provided by the grid; and/or minimizing local voltage deviations compared to local bus reference voltages for each connection to the wind turbines, by: calculating sensitivity coefficients for the wind turbines; and regulating local power references comprising an active power reference and a reactive power reference to each of the local controllers based on the calculated sensitivity coefficients.