Asymmetric Modeling of Induction Machines Using Bars and Rings Current in Interior Fault

In this paper, effects of rotor abnormalities such as broken squirrel-cage bars, broken cage connectors of induction machines are presented. The characteristics of an induction machine are changed by interior faults. Recently, the induction machines modeling for rotor fault analysis are based on the mesh current modeling but the approaches are very complex and expensive. In this paper, simulation results for two types of interior faults such as squirrel-cage bars and ring segments broken are illustrated in the asymmetrical model of induction machines. This model could separately calculate end-ring and bars current in healthy and fault conditions. Simulation results show that, noticeable low frequency harmonic modulation in the three phase stator currents and electromagnetic torque. Low frequency harmonic modulations in steady-state condition are more effective than starting condition. By the procedure, the bars and rings current are simply calculated in healthy and fault conditions [1], [2]. The advantages of this procedure are simply and possibility to calculate bars or rings current, electromagnetic torque and rotor speed in rotor fault conditions.