I’ve shared this a number of times but I don’t think many have read it, but lays out the control paths for the current F1 PU's.
Co-authored with Ferrari:
https://www.mdpi.com/1996-1073/14/1/171
Today, Formula 1 race cars are equipped with complex hybrid electric powertrains that display significant cross-couplings between the internal combustion engine and the electrical energy recovery system. Given that a large number of these phenomena are strongly engine-speed dependent, not only the energy management but also the gearshift strategy significantly influence the achievable lap time for a given fuel and battery budget. Therefore, in this paper we propose a detailed low-level mathematical model of the Formula 1 powertrain suited for numerical optimization, and solve the time-optimal control problem in a computationally efficient way. First, we describe the powertrain dynamics by means of first principle modeling approaches and neural network techniques, with a strong focus on the low-level actuation of the internal combustion engine and its coupling with the energy recovery system. Next, we relax the integer decision variable related to the gearbox by applying outer convexification and solve the resulting optimization problem. Our results show that the energy consumption budgets not only influence the fuel mass flow and electric boosting operation, but also the gearshift strategy and the low-level engine operation, e.g., the intake manifold pressure evolution, the air-to-fuel ratio or the turbine waste-gate position.
to quote...
As a consequence, the turbine is oversized and in general produces more power than absorbed by the compressor, such that part of the energy contained in the hot exhaust gases can be recuperated by the MGU-H and fed to the battery or directly to the MGU-K.
power recuperated from the extra enthalpy contained in the hot exhaust gases is directly fed from the MGU-H to the MGU-K.
And Honda outlines some of this as well
https://global.honda/en/tech/motorsport ... =Formula-1
Extra Deploy is like Extra Harvest, but the energy flow is reversed. Because the amount of energy allowed to be sent from the ES to the MGU-K is limited to 4 MJ per lap, energy over this maximum is sent to the MGU-H where it accelerates the rotor for a moment only and then recovers the inertial energy from the rotor. The electrical energy generated as a result is sent directly to the MGU-K as a way of legally exceeding the 4 MJ of energy allowed to assist the MGU-K. Use of this Extra Deploy control technology is expected to achieve lap time gains of 0.2 to 0.3 seconds.