Experimental investigation of the noise, vibration and harshness performances of a range-extended electric vehicle

Abstract

The electrification of vehicles has caused a great change in the characteristics of noise, vibration and harshness. A rangeextended electric vehicle has complicated noise and vibration problems because it behaves both like a traditional vehicle and like a battery electric vehicle as well as having its own specific noise, vibration and harshness properties. Therefore, increasing attention should be paid to these issues. This paper is intended as a contribution to the current research on the noise, vibration and harshness of a range-extended electric vehicle. The electric driveline, the auxiliary power unit and the accessories, including the power steering pump, the electric vacuum pump and the air conditioner compressor, are tested and their noise, vibration and harshness performances are analysed. The results indicate that the highfrequency noise of the electric driveline and the vibrations of the auxiliary power unit and the air conditioner compressor are crucial noise, vibration and harshness issues of a range-extended electric vehicle. Some improvement methods are implemented or proposed for better comfort in the passenger compartment. Application of a material which is sound insulating and sound absorbing proved to be an effective countermeasure. The design and refinement of a vibration isolation system for the auxiliary power unit and the air conditioner compressor are of great importance. A reduction in the low-frequency torsional resonance of the auxiliary power unit shaft during a start-stop process is a new problem compared with that of a conventional engine. It is necessary to find a well-balanced compromise between the expected acoustic feedback and the power demand.

Study on Electromechanical Coupling Characteristics of an Integrated Electric Drive System for Electric Vehicle

“…As shown in Equation 7, ω et is the maximum electrical angular speed that a motor can achieve in the constant torque region. And the base speed ω rt can be described by Equation (8).…”

“…In addition, the torque response of electric motor is 10-50 times faster than that of internal combustion engine (ICE). During rapid launch process of EV, the sudden torque step produced by motor will lead to the driveline torsional vibration, where the low frequency longitudinal vibration occurs in the range of 2-10Hz [8]- [10]. In order to suppress the launch vibration of EV, reference [11]- [14] adopted feedforward control and feedback control to increase the system damping.…”

Active control of hybrid electric vehicle launch vibration in pure electric mode

“…However the high response of the electric motor will lead to the driveline vibration in the drive shaft and propeller shaft. In pure electric launch condition, a sudden torque step in motor can activize the driveline vibration, where the low frequency longitudinal vibration occurs in the range of 2-10 Hz (Guo et al, 2015;Parmar et al, 2014;Zhang et al, 2013). Thus control designs that reduce such reluctance ripple caused by electric motor are essential to be addressed during HEV development.…”

Modeling and active control of power-split hybrid electric vehicle launch vibration

“…Due to the quick response of the electric motor, it is easy to activate driveline vibration, in which low frequency longitudinal vibration occurs in the range of 2-20 Hz. [1][2][3] Thus, it is essential to suppress this driveline vibration during HEV development.…”