Influence of Short-Circuited Turns Inductance on Inter-Turn Short Circuit Current

For sustainable electric drives, reliability is a key element, as a reliable design endures and sustains itself over time. In the context of electric machine design, the awareness on reliability has led to the investigation of various kinds of faults, with the aim of preventing them or limiting the fault-related damages. With a focus on winding faults, one of the most critical is the inter-turn short circuit. This work analyzes the behavior of an 8-pole 12-slot electric motor with concentrated windings under an inter-turn short-circuit fault condition in one of the windings, using a finite element approach. Based on this, a methodology is proposed and applied to accurately calculate short-circuit inductances and thus investigate the influence of key geometric parameters on the short-circuit current and the resulting motor torque. In particular, the effects of the stator slot opening and the position of the shorted turns within the slot are examined, providing valuable insights for the design of machines with enhanced fault tolerance. Experimental results obtained from a motor prototype are in good agreement with the predicted short-circuit currents, confirming that these currents are significantly influenced by both motor design parameters and fault location in the slot.