Mercedes Power Unit Hardware & Software

[godlameroso]

Technically there's no limit on the overall charge of the battery, only that you only deploy no more than 4MJ to the k per lap. Again this seems open to interpretation because they could have so easily have been a little more specific. Saying something like the total capacity of the ES SoC is 4 MJ per lap when mguh and k harvesting are combined. But they don't say that, so you have to assume unlimited really does mean unlimited. They could have at least said that power from the ES to the H is limited by SoC per lap. They don't say that though, they say unlimited. I honestly don't see what the problem is, as long as your SoC is 4MJ per lap and you abide by not deploying more than that to the K per lap as per regulations.

The text in Energy Store of the power unit energy flow says:
The difference between the macimum and the minimum state of charge of the ES may not exceed 4MJ at any time the car is on the track.
So you can charg and discharge the ES with the MGUH as much as you want, but you can't have more than 4MJ in the ES.

To be pedantic. It is possible to comply with this regulation by cycling between any two States of Charge 4 MJ apart. I don't know if there are technical advantages to not discharging right down to zero or if deployment regimes ever get close to zero. I would expect that most of the time during the race the cycle amplitude is around 2 MJ. Deep discharge is probably relatively rare.

What I suppose happens is that you think of the ES as a tank, the tank has a flow limit 120kW and you can only release a certain amount of stuff in the tank 4MJ(33.33 seconds per lap), but the actual capacity of the tank is 6, 7, maybe even 8 MJ. Now, the flow rate and amount you can dump per lap to the MGU-K is fixed at 4MJ and 120kW, but you can still have stuff in the tank left over, and because you're not limited in how much you can put in the MGU-H or into the tank from the H you can use that extra energy and not be penalized for it because it's unlimited. Now you probably shouldn't drain the battery all the way, but you can probably get away with it in bursts. Under normal operation you will always have a safety buffer, past that buffer you run the risk of dendrite propagation in the cells.

No team will publish the kWh capacity of their energy cells, so we're left in the dark in that sense, which is a shame because I think it could be a very interesting discussion.

[NL_Fer]

The drawing says the difference between maximum or minimum soc is 4MJ and it only says the Fia will use sensors to measure the electrical flow's. I guess they can determine if the soc has a larger difference than 4MJ.

I cannot find if the mgu control unit is programmable or if they are just slave devices controlled by the standard ECU.

And to be honest, i think the secret is in the combustion, not the ERS. Probably the Merc ICE produces a shitload of exhaust gas with good recoverable energy in it.

[godlameroso]

I think it's in how all the systems work together, because better ERS can give you better combustion, better combustion can give you more energy to recover, so it's a bit of a recursive loop.

[PlatinumZealot]

Why people waste time trying to do these ERS calculations? The energy management is so complex even for a simple track.

[henry]

Why people waste time trying to do these ERS calculations? The energy management is so complex even for a simple track.

For the same reason people endlessly discuss aerodynamic refinements. It extends their, and others, general understanding.

[NL_Fer]

So does Lewis have bad luck? Did he stress his engine to much in Singapore? Did the factoryworkers stress to much finishing 3 complete engines in a hurry for the Belgian GP?

[hurril]

So does Lewis have bad luck? Did he stress his engine to much in Singapore? Did the factoryworkers stress to much finishing 3 complete engines in a hurry for the Belgian GP?

Maybe Lewis on average uses the higher engine modes more often. Maybe his driving style puts more pressure on it.

[ringo]

driving style cannot destroy an engine these days.
The energy management system alone shows you can't do this if you are driving to deltas and doing conventional gear shifting and throttling.
A brand new engine makes it even worse, There's just no way pressing wire driven pedals in these cars will cause an engine to grenade.
I suspect there was some ignition issue or fitment issue inherent to this chassis. Doubt it's driving style.

[Facts Only]

From my one viewing of the engine letting go, that looked very much like a burst Turbine Wheel to me, or at last a failure of the Turbine seal or bearings. The rear wheels weren't shuddering or loccking up and there wasn't enough unburnt oil coming through for it to be a terminal internal engine issue. The engine still appears to be running with oil being sprayed into the hot tailpipe, which was being burnt off at very high temperatures and with a high flow rate suggesting to me that the engine was operating and providing plenty of exhaust gasses. I didnt notice anything much from the airbox either suggesting that the failure was confined the the exhaust side.

Just my initial thoughts though.

[deschrijver]

Could be an oilpump issue also.
Less oil to the bearings of the turbo.

[godlameroso]

Blue smoke is a dead giveaway if it was engine related you'd see black smoke as well from unburned fuel.

[toraabe]

If there is a hole in the crankcase it could be a broken MGU-K, broken conrod,..

Last year Hulkenberg suffered from a broken crankshaft in the US gp....

[hurril]

If there is a hole in the crankcase it could be a broken MGU-K, broken conrod,..

Last year Hulkenberg suffered from a broken crankshaft in the US gp....

It looked like water/ steam with an oil film that caught fire to me.

[Facts Only]

The Turbo unit will be water cooled as well so burst turbine wheel could also lead to water wvapour/steam.

[hurril]

The Turbo unit will be water cooled as well so burst turbine wheel could also lead to water wvapour/steam.

Sure! Not trying to argue anything.