A low-speed and heavy-duty electric powertrain was selected as the research object, the influence of electric powertrain characteristics on whole vehicle noise under accelerating condition (Speed range 800 r∙min−1~2200 r∙min−1; Torque range 500 N∙m~960 N∙m) was studied. Considering the traveling characteristics around the city, the interior and powertrain noise were recorded as the accelerating working range (10 km/h~50 km/h). Based on recording data, combining the noise generation mechanism of the motor and transmission, the components of the interior noise and motor/transmission noise were analyzed qualitatively using the order spectrum analysis; the contribution of the electric powertrain noise components to the interior were calculated quantitatively using the partial coherence analysis method; finally the measuring and analyzing methods of effect of electric powertrain on interior were built, which provided certain theoretical support for further improving the noise of electric powertrain and whole interior.
Results shown that when the vehicle is running during 3rd gear, the noise in the vehicle is mainly caused by the shifting gear noise, Constant-mesh gear engagement noise and the stator tooth groove harmonic noise. When the speed is 20 km/h and 25 km/h, the noise is mainly affected by the gearbox. When the speed is 35 km/h and 40 km/h, the noise is mainly affected by the motor.