Series hybrid drive-system - reference
- Thread starter Miles
- Start date
TPA
10 kW
This seems similar to the hydraulic drive argument for bicycles.
The basis is that the inherent losses involved in changing from one energy source to another, then back again is not worth the effort. It is also said to add more, heavier, and costlier components. But I am not a naysayer! Do it if it works!
The basis is that the inherent losses involved in changing from one energy source to another, then back again is not worth the effort. It is also said to add more, heavier, and costlier components. But I am not a naysayer! Do it if it works!
John in CR
100 TW
I've been toying with the idea of this type of "electronic transmission" as a means to satisfy the pedal requirements here in order to make my e-motorcycle legally a bicycle.
John
John
paultrafalgar
10 kW
Thanks for posting that, Miles, it's VERY INTERESTING research. I wish it had been commercialised. If you get any more news of it, please post it.Miles said:
One idea that this triggers is:
Would there be any advantage in using a rowing style motion to charge the battery/drive the motor compared to pedalling with a circular action? It would seem that on a recumbent where one could push against the back of the seat thereby using the back muscles, it might be an advantage. At first, I thought that you could add a pulling effect using the arms, but that would take your steering function away.
Picture both feet pushing one hinged board attached to a highly geared rack-and-pinion drive (or something better). Is rowing more efficient than cycling?
Or is it time for the straight-jacket :wink:
Paul,paultrafalgar said:
There are quite a few bikes like this:
http://rowingbike.com/site/EN/Home/Introduction/
http://rowingbike.free.fr/
You need to get someone to buy you this book, for Christmas:
http://books.google.co.uk/books?id=0JJo6DlF9iMC&printsec=frontcover&dq=bicycling+science :wink:
Check out Peter's bike:
http://endless-sphere.com/forums/viewtopic.php?f=2&t=3423
He used a small brushed motor as a generator powered by the pedals. Not super efficient, but you can contribute energy at any speed.
http://endless-sphere.com/forums/viewtopic.php?f=2&t=3423
He used a small brushed motor as a generator powered by the pedals. Not super efficient, but you can contribute energy at any speed.
John in CR
100 TW
fechter said:
I have a few different brushed motors that are lightweight enough for this purpose. My thought for simplicity is a gearing that will generate slightly north of pack voltage at a comfortable cadence and direct connect with diodes preventing reverse flow. It just requires a specific cadence to do any good.
For plug and play, how horrendously inefficient would this be?
Take a wide range DC/DC converter with 12V output, and put the generator output into that. Then connect a cheap inverter to the 12V from the converter, and plug the battery pack charger into the inverter. That way a wide range of voltage from the generator will do some good.
John
paultrafalgar
10 kW
fechter said:
Before y'all run away with the idea that this is inefficient read the paragraph on efficiency in the article that Miles pointed to:
quote:
Efficiency
The SH drive system does not compare with a purely mechanical chain drive e.g. of a racing bike but was not made to replace such drives, but rather to replace mechanically complex hybrid drive systems.
The first working models of the SH drive were equipped with brushed generators with peak efficiencies of between 55 and 70% and with brushed motors with about 80% peak efficiency. However we were astonished that we rode about as long and far as typical PH e-bikes. This was confirmed when Chapelle and collegues measured efficiencies of PH e-bikes of between 55% and 95%. Thus it is possible to build SH vehicles with better efficiencies than the poorer PH bikes.
So far we only discussed “peak†efficiency. If the average efficiency during the whole trip is considered, the efficiency of SHs compared to that of PHs starts to look interesting.
In urban traffic a vehicle is on constant speed only for a minor part of the travel time. Therefore the advantage of high peak efficiency at one operating point of a parallel PH remains advantageous only if the efficiency at other operating points is also good and/or if the gears are used effectively to stay in the optimal region.
People not trained in optimal operation of traditional bicycle gears often pedal off their peak efficiency because humans have a quite narrow peak of high efficiency at some power levels.
A major advantage of the SH is that the system can react more quickly than mechanical gears. The efficiency of the system can be maximized electronically at every moment. The human being can be optimally loaded: the "load-leveling" capability of SH's is very advantageous from a physiological point of view. This was borne out by the author and colleagues and by Daniel Couque (who constantly pedals a generator while manually operating the throttle of the electric motor of his velomobile). The experiences are too few to draw final conclusions yet, but it cannot be easily discounted that the physiological advantages of a SH could over-compensate the disadvantage of peak efficiency of a SH compared to a PH.
endquote.
larsb
1 MW
Read the article and missed all kinds of facts.. ”It’s possible to make an SH with better efficiency than the worst PH” ..not exactly a strong point, is it?
To me that means ”it’s not as inefficient as you think but still poor”
To me that means ”it’s not as inefficient as you think but still poor”
Hillhater
100 TW
Reviving a 14 year old thread ???
What I like about a series hybrid is that I can make one. A parallel hybrid has clear benefits, but...you either buy one or do without...
larsb
1 MW
Hillhater said:
Yeah, we all have to dig in the graveyard at times! Didn’t see how bad it was.
LewTwo
1 MW
Well if you find that interesting then you might enjoy Jay Leno's video on the 1916 The Owen Magnetic. This was arguably the first electric hybrid drive system. https://youtu.be/LYQ2PiX_Z9ospinningmagnets said:
I did make a series hybrid on a budget and even got pretty decent efficiency out of it. It also doubles as a pretty efficient trainer over the winder that actually generates electricity (not much, Fostermann I'm not).
But it will work best in a system where routing power from human to transmission is very hard - like AWD, AWS, recumbents and especially trikes, etc, and you must have a pretty damn powerful engine capable of high torque output at low speeds.
For instance, it might make creating a fully faired RWD lowracer much easier - and which can still achieve very high speeds on pure human power even with massive drop in transmssion efficiency, but with batter power to 'flatten the hills' on demand.
But it will work best in a system where routing power from human to transmission is very hard - like AWD, AWS, recumbents and especially trikes, etc, and you must have a pretty damn powerful engine capable of high torque output at low speeds.
For instance, it might make creating a fully faired RWD lowracer much easier - and which can still achieve very high speeds on pure human power even with massive drop in transmssion efficiency, but with batter power to 'flatten the hills' on demand.
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