Saturable reactor for induction motors, magnetically in shunt to the main circuit

Claim 1

In an apparatus of the character described, a combination comprising motor means having a stator provided with a fluxinducing stator winding adapted to be connected to a source of alternating current, a rotor coaxially arranged with said stator and separated therefrom by an airgap, and a shaft coaxially extending through and fixed to said rotor; and a saturable reactor comprising an annular outer member of magnetizable mAterial coaxial with said shaft, a core member of magnetizable material coaxially arranged within said annular outer member and separated by a second airgap therefrom, said members being formed with circumferentially spaced slots extending from said second airgap respectively into said members, said flux-inducing winding of said stator extending through the slots in said outer annular member of said reactor so as to form in the latter a magnetic circuit parallel to that of said motor, and two different windings in the slots of said core member connected to a direct current so that the magnetic flux produced by the direct current flowing through said core windings will pass in radial direction through said second airgap to thereby saturate said core member and said outer annular member to a degree depending on the direct current supplied, one of said windings in said core member being arranged to provide in said core member a first number of poles equal to the number of poles provided in said outer annular member by said stator winding, and the other of said windings to provide in said core member a second number of poles different from that in said outer annular member.