Variable inductor

A variable permeability inductor, comprising ferro magnetic cores coupled each to one phase of a three-phase alternative current source and forming a closed magnetic circuit through which circulates a magnetic field of a corresponding phase;

• a ferromagnetic control core forming a closed magnetic circuit through which circulates an adjustable direct current magnetic field;
• each of said phase cores being disposed with respect to said control core so as to define therebetween a common magnetic space wherein the alternative magnetic field of each phase and the direct current magnetic field are superimposed following an orthogonal plane to orient the magnetic dipoles of said common space in a direction determined by the intensity of the magnetic field flowing in said control core and thus to control the permeability of each phase core to the corresponding alternative field.

A variable permeability inductor, comprising a first and a second magnetic core forming together a closed magnetic circuit, the first and the second cores including three legs symmetrically disposed around each core and mounted in regis per pairs, in each of which circulates an alternative magnetic field proportional to one phase of a three-phase source;

• a ferromagnetic control core wherein circulates a direct current magnetic field and which is so disposed with respect to said first and second cores as to define a common magnetic space in which the magnetic field of each phase and the direct magnetic field are orthogonally superimposed to orient the magnetic dipoles of each common space in a predetermined direction and thus to control the permeability of the magnetic circuit to the alternative field of each phase.

A three-phase variable inductor to be connected to a three-phase alternative current source, including three variable inductors each comprising first closed magnetic circuit, formed of an anisotropic material through which flows an alternative magnetic field;

• a second closed magnetic circuit, also formed of an anisotropic material, through which circulates an adjustable direct current magnetic field;
• said first and second magnetic circuits being mounted with respect to one another so as to define at least two common magnetic spaces in which the respective alternative and direct magnetic fields are orthogonally superimposed to orient the magnetic dipoles in said common spaces following a direction predetermined by the intensity of said direct current magnetic field of the second circuit and thus to control the permeability of said second magnetic circuit to said alternative field, said three-phase variable inductor being characterized in that said variable inductors are interconnected according to a star-connection with a floating neutral so as to determine in each inductor an alternative magnetic field corresponding to one phase of said three-phase source and that the second coils are interconnected through a triangle connection.