DISTINCTION OF TOOTHING AND SATURATION EFFECTS ON MAGNETIC NOISE OF INDUCTION MOTORS

This paper focuses on the noise and vibrations of induction motors. It proposes an analytical method to distinguish the phenomenon responsible on the magnetic noise, especially the toothing and the saturation. A 3-speed 3-phase induction motor, which works sporadically at low speed for hoisting, serve as a support for experiments. Its acoustic noise during this operating mode is really important. A complete diagnosis is proposed with a 2D analytical model. The approach is progressive and it shows analytically that magnetic saturation is mainly responsible on these noise level. Then, the presented developments makes it possible to identify, in simple way, the noise components due to the both magnetic saturation and toothing effects.