Page 9

Focus_2012_EN

9 F o c u s Fundamental concept Our decision to increase the DC-voltage level from the usual 300-400 volt common in electric vehicles to up to 800 volt was based upon several considerations: achieving electric driving performance above 100 kW would imply an electric current of more than 350 ampere in the HV-powernet (DC), if 600-Volt-IGBT technology is being used in the inverter of the traction motor. These high current loads increase resistive losses in the HV cables; in addition, the cables become very heavy and, due to their thickness, the bending radii would create considerable problems during integration. Larger-sized cells would also need to be put into the battery, or alternatively cells connected in parallel, which would be trickier to handle in the sense of cell management. During the development of the Coup-e 800, AVL and its development partner Infineon tackled this problem by using 1200-volt IGBT technolo- > The compact electric motor is directly flanged onto the rear axle transmission. It is equipped with direct liquid cooling of the stator coil (internal winding cooling) and a dry running rotor in order to avoid plashing losses. ›› The drive segment in which our demonstrator vehicle is positioned can be referred to as the six-cylinder segment of electric mobility. ‹‹ gy and a battery with a nominal DCvoltage of 675 volt. The battery with a gross energy content of around 28 kWh is installed in the same space where the engine and the transmission would normally be. The compact electric motor is directly flanged onto the rear axle transmission, driving the rear wheels without intermediate transmission. Based on this geometric integration concept, a weight distribution of 53 percent (front axle) and 47 percent (rear axle) is achieved. Traction motor with high performance density The Coup-e 800’s traction motor is a permanent magnet synchronous motor. It is equipped with direct liquid cooling of the stator coil (internal winding cooling) and a dry running rotor in order to avoid plashing losses. Photos: AVL


Focus_2012_EN
To see the actual publication please follow the link above