Zhao, T., Liu, X., Cao, Y., Li, C. et al., "Noise Control during Idle Charging for Hybrid Vehicles," SAE Technical Paper 2016-01-1322, 2016, doi:10.4271/2016-01-1322.
A hybrid electric vehicle (HEV) will start the engine which drives its motor to charge the battery even at idle whenever the battery power is detected to be insufficient. The activation of idle battery charging could lead to serious NVH problems if powertrain parameters are not designed or calibrated properly. This work is focused on a noise issue encountered during idle charging for a specific prototype vehicle, and investigates control strategies to contain the noise level. Based on basic principles of automobile vibration and noise control along with the specific characteristics of the hybrid vehicle architecture, this work analyzes and elucidates methods of the engine idle charging noise control from the perspectives of powertrain modal alignment, idle speed optimization, and electric motor control algorithm.