High Performance Integrated e-Drive

Project targets

© Fraunhofer IISB

Single wheel traction drive for fully electric vehicles with integrated inverters.

Short description

A single wheel axle drive-unit has been developed that includes two mechanically independent permanent magnet synchronous motors (PMSM) with a reduction gear (7:1). Each motor has a peak-power of 80 kW and a continuous power of 30 kW. The maximum torque per wheel is 2000 Nm. The chosen ‘off-axis’ concept allows a flexible use in a variety of vehicle concepts, for example in small commercial vans, busses or sports-cars.

Six ‘Inverter Building Blocks’ are used to realize the double-inverter for the drive-unit with a nominal phase current of 350 Arms and a nominal DC-link voltage of 400 V. The two independent field-oriented control algorithms are implemented on a central control-board with a TriCoreTM-processor. Communication to the superior vehicle control system is realized via CAN-bus. This allows an independent torque control for each wheel of the axle. An advanced safety architecture is implemented to meet the ASIL-D safety requirements.

The power electronic components including the ‘Inverter Building Blocks’, the controller and the DC-busbars are completely integrated into the electric drive. This reduces the required space, the costs and also leads to an improved EMC-behavior. A direct connection of the motor AC-cables without additional connectors and the common use of one cooling circuit for the two electric machines and the power-electronic amongst other things reduce the material and production costs.

Project partners

SPN Hopf (Gear system, Nördlingen)

Maccon (E-machine, Munich)

 

Project duration

2009-2011

Publications

M. Hofmann, A. Schletz, K. Domes, M. März, L. Frey: Modular Inverter Power Electronic for Intelligent e Drives. IEEE-proceedings of Electric Drives Production Conference (EDPC) 2012, Nuremberg, 16/17 October 2012.