Good catch. H to ES is 2MJ, same as the prescribed 2MJ from the K to the ES. The H-to-ES charge rate is unlimited unlike from the K; so they could potentially charge the H-supplied half of the ES at a high rate, or just bleed it off gradually over the course of the lap (on throttle lap time minus ~25 sec supercharger mode).henry wrote: ↑13 Jul 2018, 19:17I was going to make the same point.roon wrote: ↑13 Jul 2018, 19:06Not quite. If full turbocompounding is used, they could still utilize the ES in a wastegates-open electric supercharger mode, with a non-H-driven MGUK, for 4MJ/lap, lasting up to 33 seconds (that oft repeated figure). Full piston power (no H reclamation) + 160 MGUK hp.atanatizante wrote: ↑13 Jul 2018, 18:48
That means producing 160HP constantly from MGU-H there is no reason to use ES anymore, isn`t it?
Only just that it`s needed to harvest the energy MGU-K is producing under braking. No to mention its use for spooling the turbo and engine ancillaries ...
Another question I would like to ask whether turbo spooling being linked via ICE through the crankshaft could aid in lowering mechanical ICE resistance (internal friction) hence lower the fuel consumption in the end?
Mechanical turbocompounding would be more efficient at specific speeds. Mechanical variability comes at a cost to efficiency and weight--transmissions, clutches, etc. I do not know which type of system (electrical or mechanical) would be, net, more efficient.
Your numbers are a little off though. In supercharger mode the drain on the ES is 120kW plus whatever it takes to drive the compressor, maybe 40kW (even with the wastegates open the turbine makes a contribution) so the max time in that mode would be 25 seconds. They would need to switch the H from driving the K to charging the ES at some point on the straights so they had another 4MJ with which to rinse and repeat.
A higher H charge rate could explain the double battery rumor. One bank optimized for charging via the K, the other bank optimized for charging via the H.