a method is proposed for operating at least one wind turbine of a wind farm including determining wind turbine individual offset information based on reactive power provided by the respective wind turbine and reactive power provided by at least one further wind turbine of the wind farm , determining wind turbine individual control information based on the wind turbine individual offset information and wind farm specific control information , operating the at least one wind turbine according to the wind turbine individual control information . further , a controller and a device as well as a computer program product and a computer readable medium are also provided .