OEM&Lieferant Ausgabe 2/2018 / OEM&Supplier Edition 2/2018

112 E-motors are designed for different configur- ations: P0 (starter-motor), P1 (integrated starter generator, or ISG after the combustion engine), P2 (ISG in front of the transmission), P3 (ISG after the transmission) and P4 (axle motor). This results in huge differences in con- struction; even speeds, torque and power can vary depending on the vehicle type. Nowadays, speeds between 15,000 and 20,000 rpm are standard. In the future, these speeds could in- crease to 30,000 rpm and higher. High speeds have the advantage that the e-motor can be constructed smaller. This reduces weight, ma- terial used and costs; at the same time, there is the danger of introducing noise and vibration (NVH). AVL’s modern e-drive test systems are there- fore built to validate e-motors with different designs, speeds and torques as well as voltage and current levels. In the design phase, e-mo- tors are often optimized in several loops. The more precise the measurements can be per- formed by the development team on a test system, the greater and more valuable is the input. This enables the improvement of mech- anics, electromagnetic performance, control or thermal behavior. This high level of data quality, together with precise measurement and control capability, is essential to be able to develop an e-drive system within a short time. An e-drive test system mainly consists of the following components: Automation system – for automation, control and data storage (e.g. AVL PUMA Open 2™) Battery emulator – for battery emulation or constant HV voltage supply (e.g. AVL E-STORAGE BE™) Innovative solutions for e-drive validation By Mario Propst, Application Manager at AVL List GmbH in Graz Using the latest technology, the experts from AVL List GmbH are simulating, developing and testing single electric components and complete electrified powertrains. Whoever wishes to develop the perfect e-drive system, consist- ing of electric motor and inverter, is faced with a whole series of tasks. On the one hand, it needs to harmonize with the electrical components such as the battery regarding communication, state of charge, temperature, DC voltage ripple and recuperation. On the other hand, the mechanical aspects need to be optimized. For example, synchronous motors display a certain torque ripple. This can negatively influence the driveability during vehicle pull-away or pro- duce noise and vibration in conjunction with the e-axle and resonant frequencies can even damage the powertrain. This torque ripple needs to be eliminated as much as possible. Images/Graphic: © AVL List GmbH AVL e-drive test system in a modular design Mario Propst is Application Manager at AVL List GmbH in Graz eMobility