Constant Starting Torque Control of Wound Rotor Induction Motors

Constant starting torque of a wound rotor motor can be achieved by inserting a fixed external element consisting of resistances and reactances combination in the rotor circuit instead of using a saturable reactor or other feedback devices. This approach provides the desired starting characteristic at a low cost of starting equipment. The generalized equations for deternining the values of external parameters for a desired starting torque are based upon a graphical approach.