Simple Series Hybrid

[88FieroGT]

I would like to eventually made a series hybrid I just need to gather my ideas and key features.

I plan on making a series hybrid that cannot be moved when the ICE doing the powering is not running , and without battery banks.... Yes I know this will lose some efficiency unless regulated precisely with a computer to vary output to match. Including at idle of the ICE without a battery bank to charge with the wasted energy.

But my ideas are besides reliability , simplicity , practicality , cost , weight , space.

So for my purposes of what I would like to make one I feel that no battery banks and no transmission and relying on the low end torque of an electric motor of adequeate power will do the job while keeping the weight down while accomplishing the others key ideas also.

I have a question to whether or not I can power my electric motor for the ICE output whether a motor or generator I have yet to decide... By transfering full output of the engine directly to the motor without a controller , and use my pedal or throttle to meter the output of the engine , with a switch at the beginning position of the throttle to close the gap from the power generated to allow me to idle my engine without any movement without needing to hold a brake.

Also I am going to research to see if I can find one but am wondering. Are there any dual shaft electric motors with a built in differential? I highly doubt it from my basic understanding of electric motors if its at all really possible without extensive cost , size , and weight.

[dcb]

re: differential, series aside, you can use dual motors and that will allow them to rotate at different speeds. Dave clouds dolphin uses two motors (with separate controllers and battery banks IIRC).

[mort]

Originally Posted by 88FieroGT

But my ideas are besides reliability , simplicity , practicality , cost , weight , space.

Hi 88FieroGT,
What you are describing could be called an electric transmission. As long as you are willing to take a hit on efficiency this is quite possible. I agree with dcb, a dual motor design would probably be easiest. There would be no problem with having the engine directly power a generator which is wired to the traction motors without a controller. At idle the generator would only be making enough power the make the motors creep anyway, like an automatic trans. All you'd need is a way to switch the wiring between forward, neutral and reverse.
-mort

[dcb]

dual motors also allows you to do a series/parallel mode, where you can apply all the current in series to the motors for more torque then switch the motor configuration to parallel for more top speed, *sorta* like a two speed transmission, with switches instead of gears.


i.e.
http://www.4qd.co.uk/faq/bmnc2.html#diff
http://www.diyelectriccar.com/forums...lel-16415.html

but there may be an assumption about a current limiting controller or something.

[88FieroGT]

Thanks for the replies... Im going to save the link to this thread to my favorites and look into those links a little later... I was just coming to check to see if I had any replies , while im waiting on some help with some heavy engine/transmission lifting.

[NeilBlanchard]

A serial hybrid without batteries is similar to the Volt. It is not an efficient way to do it, because you have to vary the RPM's and you need to be able to meet the *peak* power required, rather than just the average. And you have to run the ICE all the time, instead of about half of the time (or less).

So you have to increase the power of the ICE, and therefore you lose the main advantages of a serial hybrid has.

[Ryland]

Having even a small battery bank to act as a buffer would allow you to have a much smaller gas engine, smaller generator and greatly improve your acceleration, pretty much any small lead acid starting battery would work and your weight and space savings by having a smaller gas engine would make up for the weight and space of the batteries.
It would be crude, but you might almost be able to get away with just having a contractor to switch the battery pack in to the loop for charging and another to switch it in for powering the vehicle and if you have dual motors it could be easier to switch it in for regen braking as well, all without a solid state speed controller, of course I like how smooth solid state speed controllers work but it sounds like that is one of the things that you want to avoid.

[88FieroGT]

Sorry for the late getting back , had alot of running around to do. Also looking for missing parts , which I think I may have to replace but not too much of a biggie its something small.... But its kinda late now so I still dont have alot of time to look at those links.

But keep with the input ill chime in when I have a chance to look over everything and absorb.

[Frank Lee]

Is there supposed to be some sort of benefit to this electric transmission? I know it works for locomotives, but their situation is different.

[mort]

Originally Posted by Frank Lee

Is there supposed to be some sort of benefit to this electric transmission? I know it works for locomotives, but their situation is different.

Hi Frank Lee,
The advantage is that you're always in the best gear. There are some design and layout virtues, only wires from the engine to the motor(s). But the efficiency just isn't there and it's very expensive to implement.
-mort