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Special: These theses that change life

It is a recognized fact that PhDs bring undoubted talents and innovative skills to the world of enterprise. UTC has chosen to present - in text, videos and humoristic photos - some theses that have led to highly beneficial applications in our day-to-day life. We’d like to think that you, the entrepreneurs will be inspired to trust PhDs as recruiting officers do all around the world nowadays!

Special: These theses that change life

Contributions to improving permanent magnet, direct current, motors for high-power automobile propulsion applicationsà aimants permanents dans des applications automobiles à forts courants

All and any solutions that help lower fuel consumption are welcome. Switching off a combustion engine at a red traffic lights (even if only for a minute) is good for your purse and for the planet in terms of greenhouse gas effects. To avoid tiresome manual switching on/off moves with the starter motor, we saw the advent a few years back of “stop-and-go” systems.

“If you equip high quality urban cars with a stop and go system, the combustion engine can be restarted via the alternator”, explains Aurélien Vauquelin. This offered a first technological breakthrough, potentially allowing 100 000 re-starts (compared with previous standard 10 000 starts). “But this choice of using the alternator to provide the start torque calls for the use of expensive electronic components”. For automobile equipment makers, the challenge therefore consisted of attaining the same performance level using a less expensive technique.

Aurélien Vauquelin graduated from UTC with the major Mechanical Engineering and then did a CIFRE thesis with the equipment company Valeo, on having the starter used rather than the alternator. “This system, called Restart, will enable 300 000 restart sequences in the life expectancy of a car, which comes down to once per kilometre”. Another constraint is that you must be able to restart the engine is less than ½ second. “Technically speaking, we were seeking a high power impulse”. In short, this implies emptying the battery in a minimum time lapse without seeing the starter burst into flames!

With the help of UTC-LEC (Laboratoire Electromécanique de Compiegne) where the first stop-and-go® system was developed, Aurélien Vauquelin has added improvements to the system in the course of his PhD work. This starter is now in service and costs 5 times less that the alternator solution and leads to fuel-saving off between 10-15% per urban trip.

“The technologies developed round the concept of high power impulses could be used for electric vehicles”.