Payam Alemi - M.S Student of Islamic Azad University Science & Research Branch, Tehran, Iran
Jalal Nazarzadeh - Faculty of Engineering, University of Shahed, Tehran, Iran

The induction machines are most widely used in industrial, commercial and residential sectors. These machines work under various operating stresses, which deteriorate their machine conditions giving rise to faults. The characteristics of an induction machine change when there is interior faults. Recently the induction machines modeling for rotor fault analysis are based on mesh-current model and experimental results but the approaches are very complex and expensive. In this paper one type of interior faults such as broken squirrel-cage bars is presented. A model base on the rotor bars current is used to simulate an induction machine. A three-phase induction machine is used to study under normal healthy operation, and with one broken rotor bar. The simulation results illustrated noticeable modulations in three phase stator currents and low frequency harmonic modulations in electromagnetic torque and rotor speed. Low frequency harmonic modulations in steady-state condition are more visible than starting condition.

Induction Machines, Bars Current Modeling, Bar Broken, Simulation