Improved efficiency with adaptive front and rear axle independently driven powertrain and disconnect functionality
Journal article, 2023

Front and rear axle independently driven (FRID) powertrains are becoming a popular solution for electric vehicles (EVs) due to torque distribution capability which can enhance powertrain energy efficiency. Typically, permanent magnet synchronous machines (PMSMs) are used for FRID powertrains due to their high torque, and power density. However, the drive-cycle efficiency of FRID powertrains with PMSMs is typically reduced in comparison to single motor drives. This is due to the unwanted no-load losses of PMSMs in the field weakening region. To overcome this drawback of PMSM FRIDs, this paper proposes an adaptive front- and rear-axle independently driven (AFRID) powertrain, utilizing two dog clutches, so that the powertrain can be operated in different modes (rear, front, and all-wheel drive) by adaptively connecting and disconnecting the front and/or rear electric drive unit (EDU). A rule-based mode selection strategy is developed to utilize the flexibility of different powertrain operating modes of the powertrain for maximizing the energy efficiency of the EDU. The simulation results show that the suggested AFRID powertrain, in comparison to a common FRID powertrain, can improve the WLTC drive-cycle consumption from 22.17 kWhh to 20.50 kWhh per 100 km. Based on the route and road-load information, the energy-saving potential of the AFRID powertrain can be further improved to 20.37 kWhh per 100 km by a suggested predictive mode selection strategy, achieving an optimal mode selection.

Dynamic programming

Energy efficiency

Mechanical disconnect

Dual-motor powertrain

Mode selection

Electric vehicle


Yu Xu

Energy Conversion and Propulsion Systems

China-Euro Vehicle Technology (CEVT) AB

Anton Kersten

China-Euro Vehicle Technology (CEVT) AB

Bundeswehr University Munich

Simon Klacar

Infimotion Technology Europe AB

B. Ban

University of Zagreb

Torquery Consulting

Johan Hellsing

China-Euro Vehicle Technology (CEVT) AB

David Sedarsky

Energy Conversion and Propulsion Systems

Transportation Engineering

2666691X (eISSN)

Vol. 13 100192

HEFE - Highly efficient electric vehicles

Swedish Energy Agency (51459-1), 2020-11-01 -- 2023-10-31.

Subject Categories

Vehicle Engineering



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