Experimental research on the sound recognition of the electric vehicle motor

Abstract

By synthetically applying order tracking method and acoustic holography method, the noise source of the electric vehicle motor was discerned in the bench test. According to profiling of the test data, the motor noise order tracking diagrams and sound holography contour maps were employed to draw the noise map of the electric vehicle motor. It was revealed that the low and medium frequency components of the motor’s noise are mainly related to the rotational passing frequency of the bearing rolling element and cage, as well as the doubling frequencies of the rotational frequencies of the rotor. The medium and high frequency components of motor’s noise are mainly related to motor’s loads and speeds. In the 1000-2500 r/min speed stage of the motor with load, the main order of motor’s noise is the 72nd order and in the speed stage of 3000-5000 r/min, motor’s noise is mainly the 15th, 18th and 26th orders. When the motor speed increases from 5000r/min to 8000r/min, the main order of motor’s noise is the fourth order. When the motor was accelerated in no-load operation, its noise characteristics are different from those of the motor with load. When the motor run at no load and low speed, the 16th and 72nd order are the main order of motor noise, while at high speed, the 2nd order of motor noise and the orders of motor switching frequency noise caused by frequency converter are the main order of motor noise. The above conclusions will give the assistance to further research on the acoustic characteristic of the electric vehicle motor.

Keywords

• electric vehicle motor
• acoustic array
• recognition
• order tracking method