An electric reactor of controlled reactive power is formed by a magnetic core, and at least one primary winding to which a main current is supplied to generate a main magnetic flow on the magnetic core. The reactor also includes at least a generator of the magnetic distortion field to which a control current is supplied to generate a field of magnetic distortion on the magnetic core. The magnetic distortion field is opposed to the main magnetic flow generating a distortion of the latter, achieving a change in the magnetic core reluctance and in this way a change in the reactive power of consumption of the reactor. In addition, a method is described to adjust the reactive power in an electric reactor.