What do you know about KERS that most don't?

[Skippon]

The powertrain that won 8 races in 2012 didn't use supercaps and could easily exceed 60kW if the FIA had allowed it to!!!!!

[WhiteBlue]

I suggested a combination of battery and capacitor storage some years ago, so I doubt Adrian using the idea is a rumour. In 2014 the technology will be held back even more by the regulations.

I think in your view everything is too restrictive unless it allowed your ESERU design.

[Dragonfly]

- Maximum allowable energy store is currently 300KJ (with a max discharge of 400KJ / lap). 2014 sees this increase to 4MJ / lap

Ian

I think there's something wrong in your claims. How can one discharge more energy than is stored?
And also besides the fixed amount there is a fixed max. discharge rate in the rules.

[WhiteBlue]

The energy transfer rules for 2014 are rather complex. They are visualized in a diagram that is attached to the 2014 tech regulations as an appendix. For instance the MGU-K can not only discharge energy from the storage, it can simultaneously also utilize unlimited energy from the Turbo compounding MGU-H. So it really depends which kind of transfer you are talking specifically. Its all in the diagram.

[autogyro]

Such a pity they cant use a clutched mechanical supercharger for the engine
and use the exhaust turbine just to drive the MGU-H.

If they fed all of the heat energy electricaly to an integral MGU-K-Gearbox, there would be minimal need for energy storage.

[Dragonfly]

WB, fast_ian was speaking about current KERS system.

[fast_ian]

- Maximum allowable energy store is currently 300KJ (with a max discharge of 400KJ / lap). 2014 sees this increase to 4MJ / lap

Ian

I think there's something wrong in your claims. How can one discharge more energy than is stored?
And also besides the fixed amount there is a fixed max. discharge rate in the rules.

You're forgetting you can charge as well as discharge in the same lap...... I re-read the rules as it struck me as strange on initial read.....

I'd need to check again, but don't think there's any max discharge rate, at least this year.

Cheers,
Ian

[Tommy Cookers]

the max discharge rate is equivalent to the motor power limits (60 kW now, 120 kW in 2014)

I presume these are output values ie mechanical power
does anyone know ?

[Dragonfly]

You're forgetting you can charge as well as discharge in the same lap...... I re-read the rules as it struck me as strange on initial read.....

I'd need to check again, but don't think there's any max discharge rate, at least this year.

Cheers,
Ian

5.2.2
With the exception of one fully charged KERS, 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.

I think the bolded part is where you got confused. This is the total amount of stored energy WITHOUT the KERS storage. The latter capacity is actually not defined explicitly since the discharge rate and amount used per lap are enough. Because a larger than needed capacity is only a weight penalty. They say that RBR even have less capacity than the rest in the pursuit of less weight.

[dragosmp]

the max discharge rate is equivalent to the motor power limits (60 kW now, 120 kW in 2014)

I presume these are output values ie mechanical power
does anyone know ?

I think it's measured on the electric bus, but the rules talk about mechanical power when considering the efficiency of the conversion is @95%. So they can use 60kW/0.95 electrical power peak. I haven't figured out if the energy limit is in electric or mechanical joules, there is a small but measurable delta between them.

To another point, considering the FIA compensates for 5% power loss, it means that whoever gets an electric motor with better than 95% efficiency can in effect go a bit over the kW limit and the reverse is true if 95% efficiency isn't attained. It should be a good race to shave the last % of efficiency as 1% = 1.2kW which is almost 2bhp; not much, but it adds up.

[Tommy Cookers]

that's interesting, and useful to know

IMO the big, low-hanging fruit next year will still be the recovery of 'fake' KE by GU-K action
the engines will run at zero output torque (aka 'overrun push') when the driver has lifted off the accelerator (burning some fuel)
rather than having zero fuelling and a negative output torque ('engine braking') as in road cars
the zero torque rule will supply most of the KE harvested by the 120 kW GU-K in 2014 (as is done now for the 60 kW KERS)
(the 2014 fuel rates rules will in effect continue the supply of free fuel for this)
IMO KE recovery will continue to be fraudulent and immoral

unlike TE recovery, which is broadly a genuine recovery of waste energy
we are compelled to recover TE electrically because electrical 'push to pass' KERS was demanded (and now banned for 2014)

this position will only change if an effective limit of fuel quantity is introduced
without this there is relatively less incentive/scope to improve electrical efficiency, or thermal efficiency via TE recovery

[fast_ian]

I think the bolded part is where you got confused. This is the total amount of stored energy WITHOUT the KERS storage. The latter capacity is actually not defined explicitly since the discharge rate and amount used per lap are enough. Because a larger than needed capacity is only a weight penalty. They say that RBR even have less capacity than the rest in the pursuit of less weight.

My bad! You're absolutely correct. I stand corrected.

However, my point about using more in one lap than can be stored still stands..... We see 'em do that quite a bit in fact - Start the lap "full", use (some of) it, recharge and fire it again.

Cheers,
Ian

[Dragonfly]

[
My bad! You're absolutely correct. I stand corrected.

However, my point about using more in one lap than can be stored still stands..... We see 'em do that quite a bit in fact - Start the lap "full", use (some of) it, recharge and fire it again.

Cheers,
Ian

I am afraid this is not the case with current KERS.
The gauge you see on the TV screen resets to full only once in a lap when the car crosses the S/F line. And it only means that the ECU will allow a new portion of the allowed amount of energy to be used for that lap - either in a single shot at the max allowed rate, or in smaller portions. But that's all.
In reality the batteries probably have a bit larger capacity and recharge every time the system harvests energy under braking and is almost always charged. But the electronics in the car are programmed to the current usage rules.
It will be entirely another matter in 2014 when not only more energy can be stored and used but energy from the MGU-H can be directly fed and used by the MGU-K, coupled to the engine.

[dragosmp]

I am afraid this is not the case with current KERS.
The gauge you see on the TV screen resets to full only once in a lap when the car crosses the S/F line. And it only means that the ECU will allow a new portion of the allowed amount of energy to be used for that lap - either in a single shot at the max allowed rate, or in smaller portions. But that's all.
In reality the batteries probably have a bit larger capacity and recharge every time the system harvests energy under braking and is almost always charged. But the electronics in the car are programmed to the current usage rules.
It will be entirely another matter in 2014 when not only more energy can be stored and used but energy from the MGU-H can be directly fed and used by the MGU-K, coupled to the engine.

The gauge on the screen really has nothing to do with how much energy there is in the battery. It's only related to the amount "allowed" by the control ECU to be fed to the KERS. The battery may be full, empty or anything in between when you cross the S/F line. It's a shame that the commentators associate the gauge on the screen with the energy stored in the battery; it's probably easier to explain, but wrong nonetheless. For example, suppose a driver uses up it's full battery while accelerating on the S/F line, when he passes the line the gauge will show full although the battery can be empty; the driver brakes at the end of the line for turn 1 and fills up the battery with the Kers as generator - the gauge on the TV screen won't go up, but the battery does charge.