Regenerative Braking System

[Jacek]

Hello , could you guys tell my , does the Regenerative Braking System is charging my battery when I'm going down hill or just when I'm using brake levers ? How does it work ?
Thanks Jacek

[Leslie]

Just when you pull the brakes.  Regen has a chip called a mosfet and it is faced to feed a battery.  when you pull the brake it closes the mosfet circiut from the motor to the battery.  The battery tries to slow the bike instead of make it faster when the mosfet is faced in this way.  The battery resists the wheel turning fast making current and volts then charges the battery.

[Jacek]

Thank you for answer.

Did you measure how much current go back to the battery ? I know its dependend what speed at that moment and how weighty is the biker etc. but just aproximetly if you know , I ask becouse me and my friends discuss about it on a polish forum about Magic Pie .

Jacek

[gf3]

some time ago you said that three of the mosfets were for power and three were for regen. I don't know but I thought two of the mosfets would have to fire at the same time for the motor to work. one to supply a positive voltage and one to supply a negative voltage in my diagram below H is high impedance. nether of the mosfets connected to this phase is conducting.    

[Bikemad]

Did you measure how much current go back to the battery ? I know its dependend what speed at that moment and how weighty is the biker etc. but just aproximetly if you know.

Jacek,

These are my highest recorded regen readings so far:

• 23.35Amps (681.5Watts) using a 7cell LiPo pack (25.9V 10Ah).
• 9.65Amps (525.8Watts) using 14 cell LiPo pack (51.8V 5Ah).

Alan
 

[Jacek]

Thanks guys , now I know a little bit more about the  Regenerative Braking System .

[Leslie]

some time ago you said that three of the mosfets were for power and three were for regen. I don't know but I thought two of the mosfets would have to fire at the same time for the motor to work. one to supply a positive voltage and one to supply a negative voltage in my diagram below H is high impedance. nether of the mosfets connected to this phase is conducting.    

Yes.

There are times two are active and one is ground and times that one is active and two are ground.

These are N channel and the ground is to motor and positive is to capacitors and then battery.

The fet has a barrier diode inside that allows a path to ground if switched off and needs not to be a H bridge to work.




See this working circuit reqires no p channel for operation.

[Leslie]

The above picture has barrier diodes dioing the work.

The n channels going to the battery reversed must be charging the battery and not the the nchannles that make the motor turn.


These motor fets diodes block current from going into battery and motor charging and discharging battery in AC.

Thus all fets help regen.

[Leslie]

I am still learning this stuff.

I asked this question before and no one answered so I assumed I was correct.

I see other designs like the controllers we use and there is no mention about regen.  



I am wrong it seems.  I love it.

Can anyone priove me right?  Please. 

[gf3]

I don't think I could learn all this stuff if I lived a million years. I like the first diagram with the diodes to the centre tap of the star. I would nether of thought of that but it would make the star delta switching impossible or not worth while I think? the idea behind star delta was instead of the current going through two windings (star) the current just went through one winding (delta ) I think the people that did that conversion just had to de solder the centre tapped position and fit relays. but then again what do I know   

[gf3]

but this is more like I imagined it with h1 and L2 conducting at the same time then h2 and L3 lastly h3 and L1 then the cycle repeats its self.

one thing though this would mean that controllers would all have 6,12,18or 24 mosfets don't some have 9

[gf3]

http://ww1.microchip.com/downloads/en/AppNotes/00885a.pdf

looks like I maybe wrong to  
edit Thanks Alan for your pm
I was thinking that the regen may work like this with the regen current going through the diodes, but that would mean that regen could not come under software control

[Leslie]

Hang in there I have a good little animation comming together.  Its coooool.

[Leslie]

I made this from a flash site on some web page that I had dig into to get the flicks.

It an animated gif so you need to wait to load all the frames.

[gf3]

wow that's brilliant. That must have taken you ages
so my idea with three step was wrong there are six
any idea's how many times this cycles to make the Magic Pie turn once
I think it would be 28 because there are 56 magnets so 28 pairs of magnets