Cash Traylor
Well-Known Member
I've come to believe the starter motor/generator is producing negative torque opposing the running engine's torque to use up regen energy from the traction motor when the battery is too full to accept that energy. I could be persuaded that all of the engine's cylinders are not engaged in this effort. Someone will have to attach a separate engine run-time monitor to each of the 4 spark-plug wires.
I look forward to the results of your parachute entry to the secret vaults of Honda's secrets.
One would have to actually attach sensitive fuel flow monitors to each fuel injector to know for sure, or hack the ECU and see the engine run state. It is likely no issue for Honda to have all the spark plugs firing at all time the ICE is turning, to make absolutely sure that no unburned fuel leaves the engine. The only thing worse than inefficiency is failing an emissions test/certification.
However, using an electric motor to "oppose" a running gas engine (let's just say an irreversible torque source) is, well - a generator. And they are trying to dissipate electrical energy... The electric motor/starter must be driving some mechanical load that can absorb that rotational energy, as they cannot oppose each other without likely destroying each other. The ICE is simply taking the place of the fly-wheel in a mechanical energy storage system however in this case is a loss mechanism as a drag load. https://www.qpsolutions.net/2017/06/intro-to-the-flywheel-ups-powered-by-motion/
The point about why even bother with this versus just using the friction brakes was a good one. However I will go back to, without more detailed inverter diagrams and really detailed traction motor specifications, they likely have the real problem of where to put the generated angry pixies the traction motor is making while turning. Since in the previous article about the planetary drive configuration the traction motor cannot be mechanically decoupled from the front wheels in this configuration/design. So anytime the Clarity is moving, the PMA traction motor is kicking up the pixies, who want to go somewhere.
I think that this is a fun academic discussion, and why I love this forum. We are trying to figure out something that Honda has no interest in disclosing to the public. Kentucky will likely solve this whole discussion by attaching his ICE HOBBS meter to fuel flow sensors and gathering the requisite data!
Cheers,
Cash