Diagnosis and analysis of abnormal noise in the pure electric vehicle’s air condition compressor at idle

Abstract

A pure electric vehicle may produce an abnormal ‘clicking noise’ when idling, especially as start-up, which can be a serious problem in terms of product performance. In this paper: (1) professional evaluators carry out subjective evaluations and the abnormal noise-generation mechanism and its transfer path are analysed; (2) the mode shape and sound pressure distribution are both simulated using the finite element method; (3) the AC compressor’s sound source is identified and located in the main frequency domain using the acoustic array and image formation method, so vibration and interior vehicle noise measurements from the compressor are carried out; and (4) based on the established causes of the abnormal noise, three effective approaches – structure reinforcement, manufacturing process improvement and start-up control optimization – are presented to help prevent abnormal noises from the AC compressor.