Inertia control system for the type of wind turbines that comprises a rotor, generator driven by the rotor that interacts with a power converter to generate electricity, a wind turbine controller that comprises a blade pitch controller and a generated power controller, a power converter controller that interacts with the wind turbine controller, said inertia control system comprises: an inertia emulation block to prevent distortion in the active power output after the addition or subtraction of power proportional to the frequency change rate, by generating an extra power signal, negatively proportional to the frequency change rate, characterized in that said frequency change rate value of the block is entered in the extra power calculation block, where a block first calculates an extra power value as the negative value of the multiplication of the frequency change ratio by a parameter K inertia, that can be defined locally or communicated by an inertia emulation element in the wind farm controller, and by a value to the square of the turbine rotational speed, which is measured through the converter control unit and communicated to the wind turbine controller; the calculations of said extra power calculation block can be disabled by an inertia disable signal when a limit is reached, said extra power is added, through an output and a computation of an extra power limitation block that limits this value via configurable maximum and minimum values, to a power reference of the wind turbine controller; said extra active power is previously limited in the extra power limitation block according to a configurable parameter and the unfed power, due to the limitation, is accumulated in an element whose accumulated value before multiplication by a configurable constant is added to the extra active power;and the rotational speed reference of the wind turbine controller is adapted in proportion to the frequency change divided by the nominal frequency and by K inertia torque. and is adapted according to the grid frequency. an inertia emulation block to prevent distortion in the active power output after the addition or subtraction of power proportional to the frequency change rate, by generating an extra power signal, negatively proportional to the frequency change rate, characterized in that said frequency change rate value of the block is entered in the extra power calculation block, where a block first calculates an extra power value as the negative value of the multiplication of the frequency change ratio by a parameter K inertia, that can be defined locally or communicated by an inertia emulation element in the wind farm controller, and by a value to the square of the turbine rotational speed, which is measured through the converter control unit and communicated to the wind turbine controller; the calculations of said extra power calculation block can be disabled by an inertia disable signal when a limit is reached, said extra power is added, through an output and a computation of an extra power limitation block that limits this value via configurable maximum and minimum values, to a power reference of the wind turbine controller; said extra active power is previously limited in the extra power limitation block according to a configurable parameter and the unfed power, due to the limitation, is accumulated in an element whose accumulated value before multiplication by a configurable constant is added to the extra active power;and the rotational speed reference of the wind turbine controller is adapted in proportion to the frequency change divided by the nominal frequency and by K inertia torque. and is adapted according to the grid frequency.