Impact of Inter-Turn Short-Circuit Location on Induction Machines Parameters Through FE Computations

Abstract

This paper studies the effect of the location of stator inter-turn short-circuit (ITSC) faults on the squirrel-cage induction machine (IM) model parameter's. The ITSC location can be affected in three different ways, however we studied two of them: the physical placement for a fixed number of turns fault and the variation of the number of turns short-circuited. Both different cases will influence the rotating magnetic field shape in the air gap and thus the stator and rotor parameters. Two investigations are conducted, the former one is a finite element analysis (FEA) of the four location cases of equal severity factor ITSC in the IM phase “a.” The latter is a theoretical and mathematical analysis, where the ITSC is modeled by a step-down auto-transformer in the faulty circuit. The results of the FEA corroborate that different locations impact the IM parameters. However, the effect is not substantial and the theoretical model indicates how the parameters vary with the fault. Moreover, a comparative study of two IM damaged models that present different approach to the stator leakage inductance is performed. The asymmetric mathematical model is presented, simulated, and experimentally compared.