Transient modeling and analysis of induction motors with position effects in stator turn faults

Stator turn faults are among the most common electrical faults in induction machines. They are usually caused by the short-circuit of a few turns of a stator winding, and are difficult to locate within the winding. Because of the distributed stator windings used in induction motors, motor behavior under these faults depends upon fault location and number of short-circuited turns. This paper is concerned with transient modeling of induction machines, explicitly considering both, stator fault position and extent. The model lends itself to transient and steady-state analysis, as well as to simulation. The paper introduces a method to map the positive and negative sequence stator current information onto a polar plot, which brings into focus both, the fault position and extent. This method is suitable for on-line monitoring of motor drives. The paper also provides experimental results, obtained with an intentionally faulted machine.