Study of the evolution of an inter turns short circuit fault in induction machine

An inter turns short circuit fault is an evolving fault, the beginning of this is the degradation of the insulation of the winding of the induction machine. This degradation can be modeled with a resistance called the resistance of contact. This resistance limits the fault current flowing through the turns short-circuited. This fault current is the responsible of the defect in the electrical machine subjected to inter turns short circuit fault. From the apparition of the fault, this resistance decreases progressively until having a zero value; in this case we have a direct short-circuit. The fault severity is therefore inversely proportional to the value of this resistance. In this paper, we propose a theoretical and experimental study of the evolution of inter turns short circuit fault in induction machine. Several values of the resistance of contact are studied theoretically and experimentally for analyzing the effect of this. Simulation and experimental study are performed on a 0.25kW induction machine with 2.5% of turns short circuited in the one phase of the stator winding.