Virtual Load Assessment of Electric Drivetrains
- PDF / 1,896,156 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 79 Downloads / 180 Views
rtual Load Assessment of Electric Drivetrains As technical properties for an electric passenger car have changed, existing requirements of vehicle testing need to be adapted. Volkswagen and the Braunschweig University of Technology have jointly developed a method offering both time and cost advantages to virtually transform customer-oriented vehicle o peration m easurements available only from the combustion engine to the electric drivetrain of an electric vehicle. A VW e-Golf was used for the validation of the method.
AUTHORS CHALLENGES AND REQUIREMENTS
Florian Grober, M. Sc. is Doctoral Student in the Field of Dimensioning and Load Assumption at the Technical Development Department of the Volkswagen AG in Wolfsburg (Germany).
Dr.-Ing. Andreas Janßen is Specialist in Technical Special Analysis of Quality Assurance at the Volkswagen AG in Wolfsburg (Germany).
Prof. Dr.-Ing. Ferit Küçükay is Director of the Institute of Automotive Engineering at the Braunschweig University of Technology (Germany).
16
Electric mobility brings new challenges when it comes to a fail-safe, yet economical drivetrain design. This is due to the fact that there is less experience with field situation and testing methods for e-vehicles than for conventional vehicles powered by a combustion engine. In particular, greater differences can be seen in motor characteristics, gear ratio and recuperation. Due to the differences, the testing requirements must be adapted. In order for the experience gain to be possible early in the product development process, a new method has been devised by Volkswagen in cooperation with the Braunschweig University of Technology. The aim was the virtual transformation of existing customer-oriented Vehicle Operation Measurements (VOMs) to yet-to-be-developed electric vehicles with one or two driven axles. The basis of this method lies in the assumption that drivetrain loads are mainly a result of the vehicle’s longi tudinal dynamics, which are primarily dependent on the driving style of the driver and only secondarily on the vehi-
cle type. Consequently, the speed and longitudinal acceleration signal of the VOMs of one driver can be approximately conveyed to another vehicle. While decelerations are generally independent of the vehicle type [1, 2], a similar power-to-weight ratio and an appropriate maximum acceleration should apply for the driving [3]. Furthermore, [4] shows that customers retain their basic driving style when they switch over to an electric vehicle. Accordingly, the VOM of a vehicle with a combustion engine can be used as an alternative for the early assessment of the drivetrain loads of an electric vehicle to be developed. Based on the example of a VW e-Golf compact car, this article will show that an approximate calculation of the drivetrain loads of an electric vehicle with one or two driven axles using the longitudinal dynamics is pos sible in principle. ONE DRIVEN A XLE
Drivetrain loads can be concluded through physical correlations using the general vehicle-dynamics values
Data Loading...
