powertrain engineering 1 0 F o c u s managed to achieve a very high energy and power density while keeping the dimensions compact. This makes the battery ideal for driving a powerful sports vehicle. The vehicle range is between 115 km (NEDC) and 135 km (FTP-72).” The battery uses an innovative, integrated cooling concept: the cells are cooled via the two cell poles (conductor cooling), a concept which makes it possible to implement efficient thermal conditioning. As no additional cooling plates are needed, very little package space is required inside the battery. Another AVL innovation, which concerns the HV battery is the applied cell connecting method, which is referred to as “clinching”. This technique offers numerous benefits, such as high mechanical robustness, enhanced electrical performance compared to conventional methods as well as cost advantages in production. Active short-circuit avoidance The 1200-volt system in the Coup-e 800 also offers a great advantage when it comes to safety and driving dynamics in the event of failure: in conventional electric vehicles, a failure requires the activation of the socalled “active short-circuit”, which yields an undesired (!) braking torque, that may cause critical driving situations. In the case of the Coup-e 800’s 1200 volt system, however, this active short circuit is not needed. This is due to the fact that the motor’s maximum induced voltage at maximum speed is significantly lower than the threshold voltage of the power electronics. Peripheral components like capacitors are designed in such a way that transitions between regular operation modes and safety shutdown are uncritical. This means that the motor never needs to be switched to active short circuit. This cooling concept is achieved by the use of a sealing-tube, which is integrated inside the synchronous motor’s air gap. This innovative cooling system enables a continuous power of 140 kW and a continuous torque of 500 Nm at 2700 rpm with e-motor dimensions no bigger than 390 mm in length and a diameter of 245 mm Peak torque is at almost 800 Nm. “Our cooling concept optimizes heat dissipation directly at those spots inside the electric motor – in the copper windings and at the edges of the stator teeth – where most of the heat is normally generated. This makes it possible to achieve a very high continuous rating, which conventional motors cooled by a water jacket are only able to achieve temporarily,” the AVL electric vehicle expert explains. HV battery The HV battery used for the Coup-e 800 consists of 180 lithium-ion pouch cells all connected in series. Arranged in 15 battery modules, each module controller monitors 12 cells. The battery cell capacity is 41 Ah, which corresponds to a gross energy content of almost 28 kWh at a nominal voltage of 675 V in the HV battery. Angermaier: “With a weight of 255 kg, we have > The HV battery used for the Coup-e 800 consists of 180 lithium-ion pouch cells all connected in series. Anton Angermai e r , Head of E-Mobility and Customer Segment, AVL Software and Functions GmbH. » We have the inhouse development capa bility for all core components of the electric drive System. ‹‹
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