Solving Whine Noise in Electric Vehicles: A Comprehensive Study Using Experimental and Multiphysics Techniques

This paper examines one of the approaches used to identify the root causes of sound quality issues in vehicles, including the direct impact of psychoacoustics on the human experience. Specifically, the absence of masking effects provided by traditional combustion engines has made noise and vibration from electric drives significant factors in decision-making processes, with high-pitched tonal noise from electric motors causing annoyance and sound quality concerns for electrified propulsion systems. During vehicle testing at different speeds, a whining noise was observed, leading to an NVH test to locate the noise source. The noise is traced to the transmission by the dominating order of input reduction along with the contribution from the casing resonance. A multi-physics-based e-NVH analysis was performed, and the test data were correlated. By optimizing transmission error (T.E.) and implementing modifications to enhance the drivetrain design’s stiffness, noise levels were reduced, resulting in enhanced EV sound quality and confirming the effectiveness of the approach.”