COSIVU - Compact, Smart and Reliable Drive Unit for Commercial Electric Vehicles

The EU-funded FP7 project COSIVU [1] aims at a new system architecture for drive-trains by development of a smart, compact and durable single-wheel drive unit with integrated electric motor, compact transmission, full silicon carbide (SiC) power electronics (switches and diodes), and an advanced ultra-compact cooling solution. The main goals of COSIVU is to increase performance, flexibility as well as safety and reliability of commercial hybrid and electric vehicles, which are even more demanding with respect to power, performance, durability [2], and availability than other types of vehicles. In addition, the new architecture will be adapted to other vehicle platforms such as passenger cars. The COSIVU solution is integration of the wheel motor and the inverter into one system package. During the first twelve months of the project the COSIVU system architecture concept has been developed and a highly modular packaging concept was chosen for the power stage, using "Inverter Building Blocks" (IBB). SiC bipolar transistors and diodes have been selected and production of packaged SiC devices has started. The design of a double sided cooling version of the modules has been initiated. A theoretical design of a new driver solution, which includes power saving and reliability enhancing features, has been done. A thermal investigation test bench has been designed for the thermal characterization of the SiC based power modules.