F1technical.net

Why haven't i heard much about Renaults dual purpose alternator lately? Last year they were experimenting with ballasts that doubled as batteries and an alternator that could give a 10-20 hp boost for a few seconds at a time (similar to a hybrid)
I'm assuming that once those ballast/batteries were used up it would take a bit of time to "recharge" Apparently, so it wouldn't use power during acceleration, the batteries would recharge during braking (the alternator would recharge batteries only during downshift blips)
I thought it was brilliant and since it's easy to hide, has Renault been keeping this technology in the dark?
Maybe this could explain Renault's amazing passing domination (not to mention their awsome and consistant starts)
I'd like to hear more about this from some of you Renault experts.
PS This could also be a loophole in the engine freeze for 07...

i think thats what Max has been talking about last year. energy Reclimation it seems like the way forward with the engine freeze.

i did not hear about renualt using it. i though it was somethign that was in development for 2008

As I understand the rules, such a system is illegal in F1.

It's something they are thinking about allowing, although that might need some advanced technology and - shock horror - computer control systems.

The Toyota Prius uses such a system, it has a 3-phase AC motor that is connected to the drive train via a planetary gearbox, so that it can be driven by the engine at traffic lights etc, provide drive to the wheels and provide regenerative braking (in the form of pseudo-engine-braking).

And if memory serves Zytec raced a regenerative braking system at Le Mans a while back.

Yes, I know it is illegal but couldn't Renault be using it illegally or maybe bending the rules a bit? That's what i'm talkin' about.... it would be an easy thing to hide. An alternator is an alternator and a battery is a battery. The rest could be hidden in the electronics. "Your V8 lacking some low end hp? Kick in that alternator there Fernando!"

Switching off the alternator upon full load is a bit of an old street car trick and nothing special. Perhaps modern ECU logic could make it work while maintaining battery power.

Electrically, it's very easy to do. An alternator will "absorb" power from the drive to it depending on the amperage load demanded. In a typical road car, this is controlled by the recharging system, which usually just takes a small, constant load from the alternator to power all the car systems and keep the battery fed with a trickle charge. If the recharging system senses that the battery voltage is low, it just increases the charge going to it.
So all you have to do is reprogram the charging system to demand no charge from the alternator under acceleration, and full charge under braking. Technically, very simple to do, and also, very easy to detect.
So it can be done, but it also is easy for the inspectors to detect.

Is it actually against the rules though Dave?
It's defeinitely not a 'hybrid' part, so we're getting offtopic now!

Well, even the current "hybrid" cars such as the Toyota Prius derive all their energy from just gasoline, and manage the energy in such a manner to achieve improved efficiencies. So when we talk about racing cars that store braking energy for later use, it's pretty well the same analogy.
A electric motor can either be used to turn electrical energy into mechanical energy, or vice versa. But usually we see specific designs that are efficient at one role, be it motor or alternator. And new technologies are now making new and novel approaches feasible. One example is the Magnetic Particle Electric Clutch where torque can be transmitted between two shafts quite easily, or not, as the system commands.
http://www.reedlink.com/ProductInfo~Pro ... tches.html
The rules in F1 make a lot of this stuff illegal, but technically it would be quite easy to have an alternator connected to the transmission, and connected by a magnetic clutch. On acceleration everything is disconnected, so that most of the engine power is directed to forward propulsion. Then under braking, the clutch kickes in, and not only does the alternator assist in braking force, but it generates a lot of electrical energy to charge batteries (or capacitors), that can power systems like water and oil pumps, the computers, and the little motor that pumps Gatorade into the driver's helmet.
The future applications are varied and interesting, we shall just have to see what the rulemakers in the FIA decide.

5.3.2 The total amount of recoverable energy stored on the car must not exceed 300kJ, any which may be recovered at a rate greater than 2kW must not exceed 20kJ.

Well it sorta says the super-alternator idea is legit, but I doubt if an extra 2kW boost is worth all the extra complexity and weight. Or allowing for the 20kJ limit, you can have an extra 26bhp boost which is significant, but only for 1 second! I think simply decoupling the alternator would free up more than just 2kW.

What about the Honda Insight way of using excess energy though, the electric motor actually fires pulses into the crank to smooth out the engine. Maybe this is doable in F1 to allow 21k+ revs?

2kw is something, though. The formula is that 746 watts = 1 hp, so that's about 2.6 HP. Now if you just use that to run some systems such as power steering or the electronics, that frees up the engine/drivetrain that amount. It may not seem much, but in racing, specially F1, every percentage point is important.

The point above is under the heading:
5.2 Other means of propulsion.

Which suggests that you can store energy for the spark plugs, ecu, radio, etc in addition to the 300kJ limit for propulsion. However, there's:

5.10 Engine auxiliaries :
With the exception of electrical fuel pumps engine auxiliaries must be mechanically driven directly from the engine with a fixed speed ratio to the crankshaft.

Does this allow decoupling the alternator, pumps etc?

You coudn't decouple them - eg using a clutch etc, but there are still ways of making it work - for instance an induction motor can be made to operate as a generator by exciting it at a frequency below that corresponding to that at which it's rotating or a motor by exciting it above said frequency.

If you can match the frequency accurately enough then there'll be no torque , so it would act almost as though it weren't there. There would be inertia to worry about, but you could negate some of its effects by nudging the excitation frequency so the motor tries to speeds up or slows down under electrical action as well as mechanical action. It's largely a control problem.

Well, thanks for the technical insight everyone but does is Renault or any other team in F1 using this type of energy recovery? If it's within the rules it would be ridiculous for them not to...