Detection of inter-turn short circuits in induction machines without knowledge of the healthy state

This paper proposes a new detection method of inter-turns short circuit in the stator windings of induction machines. The analysis is focused on the external magnetic field, especially its transverse component. A specific signature is highlighted and explained by an analytical model. The proposed method is reliable, original, inexpensive and simple to implement. It has the advantage to be noninvasive and eliminate the main drawback presented by other diagnostic methods which use the comparison with a healthy state assumed known. Experimental tests are performed on a special rewound induction machine in order to validate the theoretical approach.