F1technical.net

Dr. Acula wrote: ↑

17 May 2019, 09:50

Well, let me put this topic to rest.

https://youtu.be/W4vY9zpaf5s?t=52

That's not a place on the track where a driver would normally brake, but as we can see from the onboard, the tail light started to flash, which indicates the MGU-K is harvesting.
Yes, Rosberg was in a wrong mapping for the situation, but the fact that there is a mapping at all for harvesting under throttle clearly indicates how things are. I mean he didn't get a penalty for harvesting under throttle or did he?

As much as I do believe that the MGU-k is allowed to brake the power output anytime, that video does in fact not support your claim. The blinken lights merely proves that there is regeneration happening but that probably comes from the MGU-h.

Considering the K stands for Kinetic, this means brakes. So to harvest with the MGU-K a driver would need to apply a braking force(or lift).

As far as I know these are all via engine maps which the driver can set. So the MGU-K can't autonomously operate

wesley123 wrote: ↑

17 May 2019, 11:44

Considering the K stands for Kinetic, this means brakes.

No, it doesnt mean just brakes. It means movement.
If the car was coasting, it still has kinetic energy. Even the MGU-H is actually harvesting kinetic energy from the turbo, but that kinetic energy comes from the compressor converting the energy in the exhaust gas into kinetic energy.

hurril wrote: ↑

17 May 2019, 11:18

As much as I do believe that the MGU-k is allowed to brake the power output anytime, that video does in fact not support your claim. The blinken lights merely proves that there is regeneration happening but that probably comes from the MGU-h.

The lights only mean that the PU is not deploying electrical energy. It's done to warn the drivers behind that the car in front might be slower than them.
It could mean that the MGU-K is at 0%, or it could be harvesting at 100%.

ian_s wrote: ↑

17 May 2019, 12:36

hurril wrote: ↑

17 May 2019, 11:18

As much as I do believe that the MGU-k is allowed to brake the power output anytime, that video does in fact not support your claim. The blinken lights merely proves that there is regeneration happening but that probably comes from the MGU-h.

The lights only mean that the PU is not deploying electrical energy. It's done to warn the drivers behind that the car in front might be slower than them.
It could mean that the MGU-K is at 0%, or it could be harvesting at 100%.

And what caused it to be in either of those two states?

henry wrote: ↑

17 May 2019, 13:18

And what caused it to be in either of those two states?

different engine modes combined with the current stage of charge of the ES. When the SOC reaches a certain point which can vary depending on map, the the deployment/harvesting changes to whatever the map decides. This can be totally independant of the throttle or brake peddle status.

ian_s wrote: ↑

17 May 2019, 13:24

henry wrote: ↑

17 May 2019, 13:18

And what caused it to be in either of those two states?

different engine modes combined with the current stage of charge of the ES. When the SOC reaches a certain point which can vary depending on map, the the deployment/harvesting changes to whatever the map decides. This can be totally independant of the throttle or brake peddle status.

Totally agree.

5.5.1 The only means by which the driver may control acceleration torque to the driven wheels is via
a single foot (accelerator) pedal mounted inside the survival cell.

Note the use of acceleration torque without qualifiers. It does not say ICE acceleration torque, nor MGUK acceleration torque. As with the rear brakes, it is known that sum torque values will be derived from mixed sources. The mix ratio is free, the sum is not. The FIA torque sensors inspect this.

Video Spanish GP 2016 car 6 in the wrong PU mode. Car 6 red tail-light blinking in no way means its MGU-K was harvesting/generating. It indicates it was no longer deploying (de-rating). It is totally wrong to attribute a blinking red rear light in dry race condition to the MGU-K harvesting/generating.

If have reading the regulations several times and i still can’t find any note prohibiting mgu-k charging under throttle. There are soms rules about the paddle - torque demand maps and it is stated, that de powerunit has to reach any torque demand from the ECU.

It does not state how torque has created. So for teams any combination of ICE+K power would be possible. I assume the MGU-K must be braking (for 10-20-40%) during partial-throttle and switchover from braking to delivering when paddle reaches full throttle.

“Rear red warning light system” In a dry race. I remember Charlie Whiting explaining (his words, word for word) “If the torque management system on the car decides that it want to go into fuel save mode then a system kicks-in. if you are flat-out on the straight and you are above a certain threshold – above 95% throttle for more than one second, and you are above 180km/h and you see a 120kw torque reduction – it flashes the rear light for a second to warn the driver behind.”

saviour stivala wrote: ↑

19 May 2019, 11:19

“Rear red warning light system” In a dry race. I remember Charlie Whiting explaining (his words, word for word) “If the torque management system on the car decides that it want to go into fuel save mode then a system kicks-in. if you are flat-out on the straight and you are above a certain threshold – above 95% throttle for more than one second, and you are above 180km/h and you see a 120kw torque reduction – it flashes the rear light for a second to warn the driver behind.”

So clearly the MGUK is harvesting under its own (ECU) control.

gruntguru wrote: ↑

20 May 2019, 00:27

saviour stivala wrote: ↑

19 May 2019, 11:19

“Rear red warning light system” In a dry race. I remember Charlie Whiting explaining (his words, word for word) “If the torque management system on the car decides that it want to go into fuel save mode then a system kicks-in. if you are flat-out on the straight and you are above a certain threshold – above 95% throttle for more than one second, and you are above 180km/h and you see a 120kw torque reduction – it flashes the rear light for a second to warn the driver behind.”

So clearly the MGUK is harvesting under its own (ECU) control.

MGUK generating would be 240kW power reduction compared to full, or near full, throttle and deployment.

If the MGUK stops delivering power to the rear wheels but does not start generating, that would be a 120kW reduction.

That is exactly why Whiting said (as I quoted him) “120kw loss reduction” and not ‘generating/harvesting. Unlike some on here, Whiting’s position couldn’t allow him to just blab blab blab when explaining FIA technical rules.

wuzak wrote: ↑

20 May 2019, 04:32

gruntguru wrote: ↑

20 May 2019, 00:27

saviour stivala wrote: ↑

19 May 2019, 11:19

“Rear red warning light system” In a dry race. I remember Charlie Whiting explaining (his words, word for word) “If the torque management system on the car decides that it want to go into fuel save mode then a system kicks-in. if you are flat-out on the straight and you are above a certain threshold – above 95% throttle for more than one second, and you are above 180km/h and you see a 120kw torque reduction – it flashes the rear light for a second to warn the driver behind.”

So clearly the MGUK is harvesting under its own (ECU) control.

MGUK generating would be 240kW power reduction compared to full, or near full, throttle and deployment.

If the MGUK stops delivering power to the rear wheels but does not start generating, that would be a 120kW reduction.

It would be rare to see a 240 kW torque reduction. The more common cases would be:

1. Accelerating with full MGUK then transitioning to ICE only. This normally happens well before top speed is reached as MGUK motoring is most effective in the earlier stages of full-traction acceleration. It would be unusual to transition immediately to MGUK braking as this is most efficient/effective near terminal velocity (lift and coast) or braking at the end of the straight.
2. Lift and coast.
3. Braking areas.

All the above transitions involve a power reduction of 120 kW or less.