Analysis of magnetic field distribution in induction motors with broken rotor bars

This paper proposes a detailed approach of the broken bars in the induction motors by analyzing the magnetic field distribution with the use of finite element. Results show accurately that the magnetic saturation is high in the area of broken bars and that the magnetic field waveforms carry the necessary information to detect this type of fault. The obtained information may be used to develop an on-line diagnosis system. For the finite element simulation a 7.5 kW, 4 pole induction motor was modeled and two types of core materials were used.