Mobility tomorrow: Will electric drives triumph?

Eleven years ago, Tesla’s first electric-powered sports car astonished the general public and established automotive manufacturers alike.

As we now know, that was the dawn of a new era in automotive mobility. Since then, important technological advances such as longer ranges and shorter charging times have made electric vehicles increasingly attractive.

Electric drives are convincing … but far from perfect

Today’s electric vehicles have overcome many of their teething problems. Experts predict a bright future for their local zero-emission drives, but there’s still work to be done. Achievements to date – and ambitious CO2 targets – are definitely a good incentive.

Form your own opinion at CTI SYMPOSIUM USA

At the 13th CTI SYMPOSIUM USA, the full range of intelligent, electrified drive solutions will be up for discussion, with a growing focus on BEVs. We invite you to dive deep into technical details and engage in interesting discussions. Stimulating exchanges of information, ideas and assessments await you – both in the plenary, and during the ten parallel sessions.

Electric drives: what can the next generation do better?

In his presentation, Harsha Nanjundaswamy (FEV, USA) will show how EV system efficiency and range can be improved in future. The speaker will cover the full range of possibilities and explain key development trends in battery and charging technology, e-motors and power electronics. A case study will discuss how drive efficiency and range can be improved by custom-designing the overall battery/e-motor/inverter system for a specific application.

Are multi-speed transmissions an interesting option? Smooth, powerful, shift-free acceleration from standstill to top speed is a hallmark benefit of electric drives. That said, multi-speed transmissions are still worth considering in certain cases.

In his holistic examination, Dr. Andreas Schild (IAV, Germany) will assess the need for multi-speed transmissions from different angles, taking a wide range of factors into account. For example, it’s

important to remember that permanent magnet synchronous machines place different demands on transmission systems than asynchronous machines. Usage of multi-speed transmissions has been hesitant so far, but that could change. Dr. Andreas Schild will offer good reasons for this trend.

Ralph Fleuren (FEV, Germany) will give a very specific analysis of scenarios in which a 2-speed gearbox is either recommended or necessary. If a specific 1-speed e-motor cannot deliver both the strong starting torque and the high top speed you require, for example, a 2-speed transmission can be an elegant way to square the circle.

Ralph Fleuren will focus on a family of 2-speed gearboxes developed by FEV for such cases. All these transmissions support load shifting, since EV customers do not accept traction interruption when shifting. In addition to recuperation, the transmissions also have a ’neutral’ feature that decouples the e-motor from the wheels to enable sailing. Other interesting details are the use of Ravigneaux planetary gear sets, and the usage of brakes instead of clutches as shift elements.

Into the future with up to 50,000 rpm

At the Technical University of Munich, the ’Speed4E’ research project aims to pave the way for Hyper-High-Speed drivelines with up to 50,000 rpm. In his lecture, project manager Marco Mileti (FZG, Germany) will present the latest research findings.

Speed4E is a highly integrated double e-driveline with two interconnected subsystems, each with its own e-motor, sub-transmission and power electronics. To run at such high speeds, every single component – from the electric motors and sub-transmissions to the overall power electronics – had to be rethought. The long list of specific challenges included bearings, seals and lubrication, thermal management, the high-frequency SiC inverter and NVH optimization. Marco Mileti will provide a detailed analysis of the 3-speed transmission his project team has designed. His description of the transmission’s topology will include insights into the two sub-transmissions, which are simultaneously highly integrated, yet independent. The Hyper-High-Speed planetary transmission in sub-transmission 1 is particularly noteworthy.

In future, Hyper-High-Speed drives could enable a leap in power density. Following successful bench tests, the next step will involve fitting one to an EV for the first time.

For its next generation of electric drive units, AVL likewise decided that increasing engine rpm drastically was the only way to meet defined specifications for higher torque and lower weight.

Mathias Deiml (AVL, Germany) will present an EDU configuration with 2 single-wheel drives, a total torque output of 5,000 Nm, a peak power rating of 300 kW and torque vectoring capabilities. The motors go well beyond 25,000 rpm and are packaged in an integrated unit with a dual SiC inverter and two single-speed gearboxes. Naturally, NVH behaviour is unobtrusive despite the ultra-high rpm. Mathias Deiml will also explain how special care was taken when designing the engine to minimize the use of rare earths. The model project explores how high power density and cost efficiency – two crucial factors for future mobility – can be combined.

CTI SYMPOSIUM USA: Experience the lectures, the discussions and the dinner!

Be there when transmission and drive specialists from 20 countries meet up from 13 to 16 May 2019 for a thrilling event: the 13th CTI Symposium USA.

Hot topics will be on the agenda throughout the ten parallel sessions, as well as in the plenary sessions. Get your expertise up to speed and discuss the latest developments with your peers and colleagues!

Another must-see is CTI SYMPOSIUM EXPO, our international marketplace for innovation. And for a hands-on experience of how acceleration can feel, why not drive or ride one of the presentation cars at the CTI TEST DRIVE event?

For many participants, the high point of the event is the CTI NETWORKING NIGHT. Set in the inspiring surroundings of the Henry Ford Museum, this dinner event is the ideal opportunity to interact with your fellow participants, speakers, exhibitors and sponsors.



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