Reduction of Unbalanced Magnetic Pull (UMP) due to equipotential connections among parallel circuits of the stator winding

摘要

Generator air gap non-uniformity causes an imbalance of magnetic forces that result in unbalanced magnetic pull - UMP. This phenomenon can cause high vibrations on the rotor. The addition of equipotential connections leads to an increment of the circulating current among parallel circuits of the stator winding, decreasing the magnetomotive force of armature reaction. Since the forces of magnetic attraction are proportional to the square of the resulting air gap magnetic induction, a change in their values along the circumference of the rotor, with the help of equipotential connections, will reduce the UMP. This solution is economically advantageous and the machine stop time can be shortened.