Diagnostic of the simultaneous of dynamic eccentricity and broken rotor bars using the magnetic field spectrum of the air-gap for an induction machine

摘要

This proposed paper is going to deal with the main new methods which are applied in both of the simultaneous dynamic eccentricity and broken rotor bars diagnosis inside the induction machines. The proposed method is based on the Fast Fourier transform, or spectral analysis of the measured magnetic flux density in the air-gap. More particularly, this paper deals with the use of a finite element method capable of modeling the induction machines which is called Finite Element Model of an electromagnetic calculation from the Maxwell's equation. A various techniques in the literatures are used, such as motor current signature analysis during operation. This work also proposes the internal magnetic flux density signature. Various models are extended to define the method of creating faults around the machine, whereas each model is specified by its technique. The main technique in this work is based on a finite element method, where the faults of rotor bars are created by deleting's operation of the boundary and the field of the rotor bar, which means it will be a part of the air-gap, after that, the dynamic eccentricity is formed by the movements of the rotating center of the rotor with different ratings. The results of these simulations are presented and could be considered as a rotor's failed diagnostics in the induction machine. Before last, we using the magnetic vector of the air-gap of sampling time and the sectional line in the machine for located rotor faults. Finally, we have dealt with how to identify an isolated and combined rotor faults in the indexed harmonics of magnetic flux density and compared by the healthy state of the machine.