Turn to Turn Short-Circuit Fault and High-Resistance Connection Analysis for Induction Motor During Startup Transient

In this paper, we study the effects of turn to turn short-circuit faults (TSCFs) and high-resistance connections (HRCs) for soft-starter fed induction motors (IM). Previous proposals are based on sequence components. However, most of them only consider sinusoidally distributed windings, without including harmonics in sequence components. We analyze the effect of TSCF and HRC on the fifth harmonic of the IMs current. This analysis is based on an analytical model that includes TCSF and HRC in any of the phase windings considering the h-th harmonic in the supply voltage. Experimental results demonstrated that the positive-sequence magnitude for the 5th harmonic of the current is a good indicator for TSCF and HRC detection during startup transient.