Sound Quality of the Acoustic Noise Radiated by PWM-Fed Electric Powertrain

High-frequency components of acoustic noise radiated by the electric powertrain make the subjective perception of electric vehicles worse than expected under certain operating conditions. In order to investigate the influence of acoustic components on sound quality, a pulse width modulation (PWM)-fed electric powertrain is studied in this paper. First, the acoustic noise of the electric powertrain is collected in a semianechoic chamber. Then, two types of acoustic components of the electric powertrain, namely harmonic order noise and switching noise, are distinguished through the analyses of supplied current from the inverter and gear vibration. Furthermore, the relationship between subjective perception and spectral characteristics of the noise is discussed, based on which sensitivity is established. Subsequently, the contributions of acoustic components to psychoacoustical parameters are determined. After that, a sound quality model of the acoustic noise radiated by the electric powertrain is established. The comparison between jury test and prediction shows that the established model can be used for sound quality evaluation of the electric powertrain. Finally, the influences of harmonic order noise and switching noise on subjective perception are discussed. The main original contribution of this paper concerns the influences of harmonic order noise and switching noise radiated by PWM-fed electric powertrain on sound quality.