Planned issue on Electric Mobility: The steep climb from vision to reality

Planned issue on Electric Mobility: The steep climb from vision to reality

Electric mobility is the hottest – and most controversial – discussion topic in the automotive industry.

Top up your information levels at the 16th CTI Symposium Berlin

Several lecture series are dedicated entirely to electric mobility. Numerous Expert Talks will provide the facts at first hand, and the plenary speakers will also be giving e-mobility lots of space. Wolf-Hennig Scheider, Management Board Chair and CEO at Mahle Group, will set the mood for participants in a keynote entitled ‘System Developments for the Electric Powertrain’.

How fast can we catch up with more than a century of development?

Internal combustion engines have enjoyed unparalleled success since the day they were invented. Today, they continue to define a unique era in human mobility. Modern automobiles are fun to drive, and use every drop of fuel to the max.

Electric drives, on the other hand, have some catching up to do. Critics love to point out the serious problems with technology, acceptance and infrastructure; fans highlight not just the ecological necessity, but also the breathtaking speed of technological progress and the extremely short development cycles. Their motto: if you can think it today, you can build it tomorrow.

So can e-drives live up to their role as a beacon of hope for tomorrow’s mobility? How quickly can we overcome the technical hurdles? The 16th CTI Symposium Berlin offers ample opportunity to get the facts, discuss the issues, and reach your own verdict.

Electric mobility – new start, new opportunities

The only way to develop a battery electric automobile is to start from square one, because e-drives differ so greatly from conventional drives. In his Expert Talk, Dr. Fabian Schüppel from IAV GmbH will explain this hypothesis in detail.

With e-drives, for example, the battery’s temperature and charging status have a major impact on power availability. For an e-motor to deliver maximum performance the battery needs an 80 -100 percent charge and temperatures between 10 and 30°C; outside that window, performance can drop dramatically. Also, fast charging systems (>150 kW) have special requirements. Hence the call for a ‘total revolution’ and ‘restructuring’ of development processes in key segments such as powertrain, braking system or temp management – to create ‘opportunities for competitive, future-proof long range electric mobility’.

800 volt technology – charging in your coffee break

No-one would deny that EVs work outstandingly well in urban traffic or on short trips. But while established technology has done a respectable job of improving range, electric mobility and long distances are generally still seen as a contradiction in terms.

For Dr. Klaus Küpper from AVL List GmbH, the solution lies in 800 volt technology to enable fast charging of our steadily-growing battery capacities. In his talk, he cites the advantages and shows the technical hurdles this key technology entails. The most critical factor is battery thermal management, since high-speed charging puts a significant load on the battery cells. At the same time, all powertrain components need to be suitable for 800 volt operation. For inverters, for instance, silicon carbide technology (SIC) will likely play an important role.

With 800 volt batteries as energy storage devices and a corresponding charging infrastructure, recharging downtime can be significantly reduced. That opens up interesting perspectives for e-drives in medium duty trucks too.

30,000 rpm – taking transmission technology to the limit

So do e-drives actually need a shift transmission? That’s a provocative question – and the answer is a resounding yes. E-motors may produce high torque in all driving scenarios, but like any other motor or engine, they run more efficiently with the right transmission. The goal is to keep the e-motor running in its ‘sweet spot’ as often as possible, whether in urban stop-and-go, on the highway or on steep hills.

To further improve power density, developers are aiming for e-motors with extremely high rpm. For transmission technology, handling a maximum input of 30,000 rpm presents particular challenges.

Working within the ‘Electromobility Southwest’ cluster, the Karlsruhe Institute for Technology (KIT), has collaborated with Bosch and Daimler to develop a high speed powertrain with a seamless shift 3-speed transmission, in a project called Effect 360°. The transmission was optimized in terms of efficiency and build size in a software-assisted development process that took specific framework parameters (such as vehicle class or the characteristics of other component systems (e-motor, performance electronics, battery system) into account.

The results of the research project will be presented in an Expert Talk by Dipl. Ing. Uwe Reichert. The combination of an e-motor with a maximum of 30,000 rpm and a 3-speed transmission proved to be advantageous. Compared to a 1-speed reference drive at lower maximum rpm, it achieved higher power density at competitive system efficiency levels.

E-drives as a system – the components were made for each other.

When you not only see individual e-drive components as a system but also combine them mechanically in a compact drive unit, you can boost efficiency and save space and weight.

In his lecture, Peter Janssen from FEV Europe GmbH presents a highly integrated EDU (Electric Drive Unit) that unites the e-motor, gearset, differential, dual inverter and cooling system in a single casing. The compact gearset uses a planetary gear train with no annuli. This innovative solution is free of axial and radial forces, which makes for excellent NVH performance. At development stage one, the concept envisages cooling the inverter and e-motor stator with water. At stage two, modern silicon carbide (SIC) technology can be used to do away with a water circulation system entirely. The EDU boasts numerous new features that all add up to exceptional system-level power density and greatly improved NVH performance.

Technische Universität Munich’s research project ‘Speed2E’ takes an unusual approach. The drive comes from two high-rpm e-motors with two parallel sub-transmissions, one of them shift-enabled. In his talk, team leader Martin Sedlmair presents the latest insights from both simulations and prototype experiments. The effects of ultra-high (up to 30,000) rpm were particularly interesting. The team also examined two different operation strategies, depending on whether optimized NVH performance or efficiency was top priority. The test results document the huge potential of this highly innovative, high-rpm powertrain, which can boost efficiency and comfort in EV production-vehicle development.

Bright ideas for drives with an ICE too!

In all areas of drive technology, progress continues in leaps and bounds. With around 100 Expert Talks in the plenum and 16 parallel lecture series, a comprehensive programme awaits you at the 16th CTI Symposium Berlin. Why not come and be inspired by the vast range of topics and the engineers’ ingenuity. We look forward to welcoming you in Berlin.

Find all information about the lectures at the 16th CTI Symposium in Berlin in our program: