Influence of temperature on the vibro-acoustic behavior of claw-pole alternators

Audible noise of automotive alternators is a key point for future cars. Its reduction requires a multiphysic approach including electromagnetic, vibro-acoustic and thermal aspects. In this perspective, this paper investigates the influence of stator temperature on the acoustic noise of a claw-pole alternator. Experimental results show a clear reduction of sound power level and change in noise peak frequencies with an increased temperature. An experimental modal analysis of the stator is carried out to explain this effect. Based on these measurements, a model is developed to predict the resonant frequencies of the wound stator at different temperatures.