Ferrari Power Unit Hardware & Software

[Tommy Cookers]

@ SonicBoom

initial braking power at the rear axle can be c. 1000 kW - this then falls rapidly with falling speed and downforce
ie most of the braking energy is flowing at a rate far beyond the rate at which a 120 kW MGU-K can capture energy
the rear braking energy rate only falls to 120 kW at rather low speed and downforce

so a 120 kW MG can only capture/provide a fraction of the total rear braking energy

[SonicBoom]

@ SonicBoom

initial braking power at the rear axle can be c. 1000 kW - this then falls rapidly with falling speed and downforce
ie most of the braking energy is flowing at a rate far beyond the rate at which a 120 kW MGU-K can capture energy
the rear braking energy rate only falls to 120 kW at rather low speed and downforce

so a 120 kW MG can only capture/provide a fraction of the total rear braking energy

Good point, I had overlooked both the effect of the aero drag and the peak braking capacity.

Since this idea of recovering additional energy from the MGU-K is centred around actually having it available, is there a simple-ish method for which we could calculate the recoverable energy? i.e. could we just say 120kW x total time under braking(per lap)? That would just assume that whenever under braking the full 120kW is being recovered.

If that is a reasonable approach, then on Sebs pole lap at Baku (crudely - based on onboard footage) the total possible recovered energy from the MGU-K is only ~1.9MJ (~16 seconds of braking)

Also, apologies if all of this has already been discussed elsewhere, I'm still new to this forum. So feel free to direct me to where it's been covered.

[iichel]

MGU-K is allowed to capture more than 120kW but is only allowed to send 120kW to the engine but it's unlimited between K and H.
Does this mean, the K is allowed to send unlimited energy to H while braking, or does this count as the 120kW taken from the engine?

Image --> https://uploads.tapatalk-cdn.com/201805 ... ec5010.jpg

[godlameroso]

MGU-K is allowed to capture more than 120kW but is only allowed to send 120kW to the engine but it's unlimited between K and H.
Does this mean, the K is allowed to send unlimited energy to H while braking, or does this count as the 120kW taken from the engine?

Image --> https://uploads.tapatalk-cdn.com/201805 ... ec5010.jpg

The K is allowed to transfer more than 120kw/200nm of torque only to the control electronics and then the MGU-H(then to wherever). But you can only power the MGU-K via engine braking and engine ancillaries, both of which are limited to 120kw/200nm of torque total. You can't get out more than what you put in so you're essentially limited to that power level. Doubtful the MGU-H is that powerful, but probably ~70-80% as powerful. Would be surprised, and intrigued if it matched or exceeded MGU-K power.

[stevesingo]

MGU-K is allowed to capture more than 120kW but is only allowed to send 120kW to the engine but it's unlimited between K and H.
Does this mean, the K is allowed to send unlimited energy to H while braking, or does this count as the 120kW taken from the engine?

Image --> https://uploads.tapatalk-cdn.com/201805 ... ec5010.jpg

The K is allowed to transfer more than 120kw/200nm of torque only to the control electronics and then the MGU-H(then to wherever). But you can only power the MGU-K via engine braking and engine ancillaries, both of which are limited to 120kw/200nm of torque total. You can't get out more than what you put in so you're essentially limited to that power level. Doubtful the MGU-H is that powerful, but probably ~70-80% as powerful. Would be surprised, and intrigued if it matched or exceeded MGU-K power.

How is this measured? Torque sensor plus rpm or is it derived from current and voltage?

[godlameroso]

Since the MGU-K is geared to the crank I'm guessing rpm plays a role, however measurement is probably in the CE as all energy has to be routed through it. I suspect you're right and there's a variety of different sensors monitoring it.

[stevesingo]

Without specifying on the technical regulations where the current/voltage is measured, how does the FiA know how much harvesting is being done and where the energy is being channelled?

Without specifying that current/voltage must be measured at the MGU-K motor terminals, it could be possible that over 120kW is being harvested, 120kW fed through the CE to the ES and the remainder fed to the MGU-K.

https://uploads.tapatalk-cdn.com/201805 ... ec5010.jpg

Looking at the diagram, 120kW limit is applied to ICE to MGU-K. This transfer is via and ring gear and pinion. Torque and rpm measurement is the only way to monitor this directly.

[Tommy Cookers]

120 kW is the measured DC electrical power - or rather 95% of the underlying DC electrical power limit

if you're over 95 % efficient from DC power to mechanical power into the crankshaft your 120 kW will be over 120 kW

these are of course not DC machines but the 'drive' is apparently supplied by the DC line
it's an interesting question - how they could drive the K separately from the DC line

[stevesingo]

The diagram in the tech regs states 120kw transfer between ICE and MGU-K. This is a mechanical connection. It can't be measured in terms of DC power.

The link between MGU-K and CE can be measured in terms of DC power. Is the nominal 95% efficiency specified in the rules?

[Tommy Cookers]

the ICE can't transfer energy to the K without doing work against the K's electromagnetic load

the rules seem to say that .....

electrical work can be applied to the K at a rate of 126.3 kW
(giving 120 kW mechanical power output if the efficiency is 95% and correspondingly more if the efficiency is more) and ...

mechanical work can be applied to the K to give 120 kW electrical power output
(mechanical power required is 126.3 kW if the efficiency is 95% and correspondingly less if the efficiency is more)

yes the 95% is in the rules

[PlatinumZealot]

Ferrari are essentially doing a "Reverse Extra-Harvest."

Instead of only bypassing the 4MJ charging limit allowed from MGUK, via the MGUH, like every manufacturer does, Ferrari are also going from battery to MGUH to MGUK using this method in reverse.

You heard it here first!

[Xwang]

Ferrari are essentially doing a "Reverse Extra-Harvest."

Instead of only bypassing the 4MJ charging limit allowed from MGUK, via the MGUH, like every manufacturer does, Ferrari are also going from battery to MGUH to MGUK using this method in reverse.

You heard it here first!

Is it explicitly forbidden by the rules?

[henry]

Ferrari are essentially doing a "Reverse Extra-Harvest."

Instead of only bypassing the 4MJ charging limit allowed from MGUK, via the MGUH, like every manufacturer does, Ferrari are also going from battery to MGUH to MGUK using this method in reverse.

You heard it here first!

You appear to have the energy flows inverted.

K -> ES is 4 MJ max per lap

ES - > K is 2 MJ max per lap.

So to use “reverse extra harvest” they would need to have more than 4 MJ to spend. This might happen in qualifying when they would need to balance longer K deployment against use of supercharger mode.

[LM10]

Ferrari are essentially doing a "Reverse Extra-Harvest."

Instead of only bypassing the 4MJ charging limit allowed from MGUK, via the MGUH, like every manufacturer does, Ferrari are also going from battery to MGUH to MGUK using this method in reverse.

You heard it here first!

Where do you have this from and is this illegal?

[Tommy Cookers]

afaik
extra harvest bypasses the 2 MJ limit K charging ERS but not the 4 MJ limit (K+H) charging ERS
it's value is increasing (by the extra) the H energy available for directly driving the K