BMW Efficient Dynamics: brake energy recovery

Transport and new transport: energy, pollution, engine innovations, concept car, hybrid vehicles, prototypes, pollution control, emission standards, tax. not individual transport modes: transport, organization, carsharing or carpooling. Transport without or with less oil.
User avatar
Flytox
Moderator
Moderator
posts: 14138
Registration: 13/02/07, 22:38
Location: Bayonne
x 839




by Flytox » 21/11/07, 19:48

Hello André
Andre wrote:Why do you want to put a clutch on an alternator?
it just adjusts the excitation and it turns lightened just two ball bearings to rotate, negligible


The clutch can only be useful if it is on the driving pulley. This avoids rotating 2 pulleys, a belt and the alternator at the bottom of the body for nothing. Sure that the gain should not be fierce but what is taken is taken .... : Mrgreen:

A+
0 x
Reason is the madness of the strongest. The reason for the less strong it is madness.
[Eugène Ionesco]
http://www.editions-harmattan.fr/index. ... te&no=4132
gabuzo
I discovered econologic
I discovered econologic
posts: 1
Registration: 23/11/07, 10:07




by gabuzo » 23/11/07, 12:03

Basically it is a good idea to recover energy from braking but I think that the fuel economy of 4% is a theoretical maximum that we will probably not reach in practice.

Explanations ...

First of all, it seems to me that the power taken by an alternator depends on the energy it must deliver. There is of course "a fixed cost" due to the friction and the efficiency of the alternator but even if the alternator could produce 5kw it would not consume the 5kw when nothing of the consumer is in operation.

Systematically going through the battery generates losses because the efficiency of the battery is far from being 100%.

Regenerative braking is a very good idea since it avoids using the brake pads and recharging the battery. But knowing that the recovery will only intervene in the event of braking (we do not brake all the time) & provided that the speed of the car is sufficient and that the braking is not too strong.

Finally there will be the capacity of the battery which may limit energy recovery.

In short, I would be very surprised that the BMW system has a significant impact on consumption in practice. That said, the system is not completely uninteresting and the coupling with a stop and go (?) Would probably be interesting.
0 x

 


  • Similar topics
    Replies
    views
    Last message

Back to "New transport: innovations, engines, pollution, technologies, policies, organization ..."

Who is online ?

Users browsing this forum : No registered users and 141 guests