Quote:
Originally Posted by PhishPhood
If true then in the three scenarios that you laid out above it seems to confirm my initial thought that in certain conditions the ICE+generator does power the e-motor directly, bypassing the battery. The path of least resistance as you note.
At this time during very strong accelerations or needs... hold your hats... the Volt would be a parallel hybrid being run at the same time by the ...
ICE ==> generator ==>
............................... both power sources feeding the e-motor by separate routes
PLUS: battery pack==>
Most of the other times the Volt is a series hybrid...
ICE ==> generator ==> battery ==> e-motor
Now the question is when the battery reaches it's lowest available level, say 30%, but the driver suddenly wants maximum output with the battery prohibited by software from contributing ( can't go lower than 30% ) is then the vehicle being driven ONLY by the..
ICE ==> generator ==> e-motor
with maybe a 'trickle charge' to the battery?
OTOH.. in the response from Lutz several pages back he apparently said that all the power from the ICE went through the battery. Either the ICE output always does go through the battery ( series hybrid ) or it sometimes takes the path of least resistance around the battery ( parallel hybrid). Therein lies the conundrum.
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Phish, its the same thing. Through, around, whatever. If there is a net energy difference while the generator is running it will go into or come from the battery. No fancy controllers required, and nowhere is it a parallel hybrid. The Prius is antiquated technology next to this. Its a VCR vs DVD sort of thing. Toyota will copy it in short order. It's just better. Accept that. Had Toyota had access to great batteries when they built the first Prius it would have been designed like the VOLT. The concept of a series hybrid with a range extending motor is nothing new.
They set it at 30%, but GM will let it go down to 29 if necessary. It's near impossible to setup a scenario where you could use more than 70hp on average over any reasonable length of time. They locked out towing, locked out high speed operation, and sized the other components appropriately.
How do we know this? That's how GM sized the generator. They used powerful computers and real world data to analyze extreme scenarios, then added a percentage. Then, they built mules of the system, drove those all over to validate their analysis. It's just not that hard. I'm still trying to understand how some on this site think GM just messed up the calculations or just guessed at the generator size and now all the Monday morning QBs on a GM fansite are right and GM messed up. When it reaches 30% its done. Turns into a 1987 Ford Escort. Guess they should have asked us first, right? Because this site is just filled with electrical and automotive engineers with prior EV experience.
Also, a parallel hybrid implies an electrical and mechanical connection to the wheels. A series hybrid means the mechanical force is converted to electricity before reaching the wheels. The VOLT is a series hybrid with a battery. A modern diesel locomotive is a series hybrid without a battery.
GM approached it from the other end of the spectrum to make it appear as a completely different class. An electric vehicle with a range extending motor. Means the same thing.
There's a key point that needs to be made. GM is dumbing everything down for mass consumption. Reading into Lutz's statements too closely, pouring over every detail released will not give one a 100% understanding of this. What Lutz was trying to convey is all the power goes to or from the battery. Not necessarily into it or from it. Many of us on this site understand this because we're the type of people who just understand things like this. It's intuitive. Everyone is good at different things, but some people need to approach this with a leap of faith.
There are plenty of people on this site who are willing to patiently explain all this, but keep this in mind - if you think GM messed up, or just don't understand - just recognize that you probably just don't understand it. Telling others they are wrong is not appropriate unless you really understand it - and what you'll notice is those of us that really do get it just know enough to know what we don't know. We freely admit we don't have all the settings, calibrations, and exact details.
However, many just don't even know enough to know what they don't know - and that's where mistakes like the one that started this thread come from.