Defects rotor identification by magnetic spectrum analyzing in a squirrel-cage asynchronous machine

This work presented the diagnosis of several defects types of the rotor bars for squirrel-cage asynchronous machine. The geometry of the model in tow dimensional is presented it consist of two sub-domain: stator and rotor. The Maxwell equations describe the local behavior in time and space of magnetic quantity, there are equations will be represented the most commune from Maxwell-Faraday, Maxwell-Ampere and equation of magnetic flux density conservation. Calculation well be done in the case of a healthy and unhealthy machine. In the first, the fractures are supposed to one, two and three broken bars adjacent, in the last we well take three different states for unhealthy machine, symmetries spaced of two broken bars, three broken bars and four broken bars. The finite element model used for solving Maxwell´s equations; in order to analyze the frequency spectrum of the magnetic flux density in the air gap. In fact, the influence of the number of broken bars adjacent and spaced on the functioning of the machine, and the influence of this last on the frequency spectrum will be studied.