Quote:
Originally Posted by P-hack
But the state of the art of electronics and motors and generators does not compare with mechanical linkages in terms of efficiently transmitting power to the wheels.
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You go too far again.
"does not compare" is correct ... but not in the way you think ... if we actually went "State of the Art" ... electronics , motors, and generators ... would trounce mechanical linkages in efficiency , power , size, weight.
My advise ... don't even open that "state of the art" door.
Quote:
Originally Posted by P-hack
Series only is good when stopped (taking a wiz), and that is basically idling, which is not a good efficiency strategy, ever.
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The "ever" part is going too far ... and is not correct.
Series vs Parallel is a whole other massive generalization , can of worms ... I suggest we stick with the more narrow ... pusher vs generator trailer currently being discussed.
Quote:
Originally Posted by P-hack
There is nothing inherently different about pusher vs generator except that a well engineered pusher has greater efficiency overall, not just peak.
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Still an incorrect over simplification.
Inherent Differences have been pointed out.
Errors of this overly broad claim have been pointed out.
Quote:
Originally Posted by P-hack
I think some of both is best, but "mostly pusher" for efficiency. I'm kind of assuming that an EV with AC has electric AC and that a pusher (or generator) should handle lights/fans/whatnot. Of course the EV can work with the pusher and just use regen (hopefully efficient regen) to keep the battery from depleting completely. Some knowledge of your situation is essential for hypermiling such a system too. It is best to use what battery power you have even on a long trip, assuming you can recharge at your destination.
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Holly crap ... progress
Quote:
Originally Posted by P-hack
I don't see how the generator is going to come out ahead in efficiency with so many losses in just getting the power to the wheels, and with no special techniques that are not also available to a pusher.
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I've already given you examples of it ... If something was not clear about them ask about it , and I will try and re-explain.
And ... there are techniques / options the generator has for efficiency that the pusher does not ... as I have already pointed out... if something about those was not clear ... ask, and I will try and re-explain.
Quote:
Originally Posted by P-hack
The situation is which is most efficient, that is all, which will turn the fuel in to miles covered being the best. Talking about powering a house isn't relevant. Because I can make up scenarios where you need to leave the house powered and leave with the car too.
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Give that man a cookie.
Situation determines which is the best fit.
Powering the house is 100% relevant if I ever want a generator to power my house... or work site power tools ... or a pizza oven at the beach ... etc.
Quote:
Originally Posted by P-hack
Either way there will be more motive traction than a front wheel drive EV has by itself.
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Situation dependent.
In the situation where the vehicle power can come from both the BEV and the trailer ... yes.
In the situation where the vehicle is being moved only by the power output from the trailer ... no.
In the situation where the Heavier BEV tires are not slipping but the lighter Pusher Trailer tires are slipping ... no.
etc.
Quote:
Originally Posted by P-hack
But if you need more traction, spring load the pusher (or better yet, hydraulically add down force on demand), or move the weight forward (and add appropriate sway damping),
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Action has opposite reaction.
The spring or hydraulics that pushes down the trailer will lift the rear wheels of the forward , being pushed by the same force ... lifting the point of connection is a VERY bad idea ... especially where that same point of connection can move side to side as a trailer connection does... this is very unsafe.( sway dampen or not)
Moving weight forward won't help ... the trailer's total weight is less ... it's tires will slip at less torque than the heavier BEV tires will.
Quote:
Originally Posted by P-hack
or make it integral to the EV like putting a generator in the trunk.
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If you are going to skip the trailer idea completely ... than sure you're a PHEV ... and that different situation then has a different result.
Quote:
Originally Posted by P-hack
you ignored some rather obvious solutions if it is even a problem for most people. Would like to focus on normal driving, not rock crawling either, like the 15,000 miles on roads that normal people use. Like so many SUVs that will never go offroad as much as my prius does. Determining "need" based on extremes is kinda futile.
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Another Cookie.
Situation matters ... if your situation doesn't need off road ... another vehicle without that feature may be a better fit for you... but if your situation does need off road ... then it does.
I am not determining need based on extremes ... I have consistently and repeatedly pointed that either the pusher or the generator could be the better fit depending on the situation ... you've been fighting against me on this... I refuse to go one sided biased either Always A , or Always B ... that would be incorrect.
Quote:
Originally Posted by P-hack
not an example of a good pusher for efficiency. A pusher that does not have all the efficiency losses of the generator system can have a smaller engine, and does not need a large generator (though a gearbox would be nice for efficiency at sub-hiway speeds), and it can carry less fuel for the same range.
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It was the example you were holding up... if you want to hold up an example of a better real world pusher ... go ahead, be my guest.
Nice theory. ... but unfortunately ... this comes back again ... depends on the situation... in some situations A > B ... others it's B>A .
Quote:
Originally Posted by P-hack
I'm not proposing that pusher except as a quick fix (though it is thoroughly robust and reliable), if you have a generator and charger and trailer laying about then why not try the generator approach?
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Quote:
Originally Posted by P-hack
I'm trying to comparing apples to apples, as well as one can, in terms of hypothetical innovative range extenders. Both can load/unload the engine with the battery, both have relatively independent speed vs rpm. Both are operated for maximum efficiency, both can downsize the engine. I don't see where the generator is going to be more efficient in locomotion, but lots of obvious cases where the pusher is.
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I've pointed some situations out for you already.
Quote:
Originally Posted by P-hack
Given how many EV's don't even have a gearbox, or even a neutral, I get the "dirty hands" feeling this must give you to even consider it, but physics are physics and our imaginations should not be limited by preconceptions.
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Many EVs don't even have gear boxes ... for a good reason.
The electric motors are not as negatively effected for efficiency and for power as ICE engines are ... as the wheel RPM and Torque changes.
I don't have any problem at all considering the pusher ... I have already posted several times ... there are situations where it will be the better option ... but I have refused to do is pretend it is one sided and always ___ is the better option ... it isn't.
Being aware of the pros and cons of both ... is the better option ... it allows the actual best device for the situation to be used... and not incorrectly assuming one is always better than the other.