Noise Characteristics for Hybrid Electric Vehicle Induction Motor

In recent years, the development of environmental friendly vehicles, such as electric vehicles and fuel cell vehicles, has further accelerated. Hybrid vehicles with regards to practical application which employ a combination of gasoline engine and electric motor remain one step ahead of the other technologies. On the other hand, as for noise and vibration (NV) phenomena, hybrid vehicles have many different features from those of conventional vehicle. Firstly high frequency noise is generated by the hybrid units, such as motor/generator and power control unit. Secondly low to middle frequency NV phenomenon tends to be worse. However, this paper describes the noise characteristics for HV induction electric motor, where its noise comprises three types namely: electromagnetic, aerodynamic and mechanical. Moreover, the influences of the cooling fans' blades number on both motor aerodynamic and total noise are presented. Special test rigs are fabricated to allow these characteristics to be measured. The results indicate that significant information can be gained these noise sources which allow these noises to be controlled and consequently the reduction of vehicle interior noise can be obtained during its operation conditions.