[PStechPaul]

Most people will say that series wound DC motors cannot provide regeneration, and reversing must be accomplished by means of a mechanical transmission. But I found the following detailed article that provides a proposal on how to do both. It also seems to include a lot of good basic electromagnetic and motor control theory. I'm still not a "fan" of series wound brushed DC motors for EVs, but perhaps this will help some of those who use them for EVs:

http://eprints.usq.edu.au/501/1/DeanTHOMPSON-2005.pdf

[major]

Originally Posted by PStechPaul

Most people will say that series wound DC motors cannot provide regeneration, and reversing must be accomplished by means of a mechanical transmission. But I found the following detailed article that provides a proposal on how to do both. It also seems to include a lot of good basic electromagnetic and motor control theory. I'm still not a "fan" of series wound brushed DC motors for EVs, but perhaps this will help some of those who use them for EVs:

http://eprints.usq.edu.au/501/1/DeanTHOMPSON-2005.pdf

Hi PS,

Fork trucks and golf carts have been reversing series wound motors, like, forever And regeneration is widely known, just commonly viewed as "not worth the trouble" when it comes to series wound motors. But thanks for the reference. You will note that the author leaves regeneration for "further work." In other words, he didn't attempt it

Regards,

major

[PStechPaul]

So if these motors can be electrically reversed they will need separate field (stator) and rotor connections. And the contactor(s) would need to be rated to carry the full maximum load current of 500A or so, which makes for a rather large and expensive component. So, although they can do this, I wonder how many actually do?

I found another thread from 3 years ago that gets into regeneration:
http://www.diyelectriccar.com/forums...egy-36888.html

Here is more information:
http://zone.ni.com/devzone/cda/ph/p/id/53

There was some caution about attempting regeneration on motors with advanced brush settings. I wonder if this also applies to reversing?

[DavidDymaxion]

Some of the NEDRA guys use the 12V system for reverse, so those components don't need to have full 500A capability.

Originally Posted by PStechPaul

So if these motors can be electrically reversed they will need separate field (stator) and rotor connections. And the contactor(s) would need to be rated to carry the full maximum load current of 500A or so, which makes for a rather large and expensive component. So, although they can do this, I wonder how many actually do?

I found another thread from 3 years ago that gets into regeneration:
http://www.diyelectriccar.com/forums...egy-36888.html

Here is more information:
http://zone.ni.com/devzone/cda/ph/p/id/53

There was some caution about attempting regeneration on motors with advanced brush settings. I wonder if this also applies to reversing?

[major]

Originally Posted by PStechPaul

So if these motors can be electrically reversed they will need separate field (stator) and rotor connections. And the contactor(s) would need to be rated to carry the full maximum load current of 500A or so, which makes for a rather large and expensive component. So, although they can do this, I wonder how many actually do?

Ones that are direct drive (without transmission). Most guys keep the tranny in the donor (it is usually there (free)) so don't mess with reversing contactors. And all the available DC series EV drive motors have separate field (S1 & S2) and armature (A1 & A2) terminals. Occasionally you see a guy using a 2 terminal series motor which is usually taken from a forklift pump drive.

I found another thread from 3 years ago that gets into regeneration:
http://www.diyelectriccar.com/forums/showthread.php/series-wound-control-strategy-36888.html

Nice to see someone use the search function Thanks. Not much has changed in this regard over those 3 years.

There was some caution about attempting regeneration on motors with advanced brush settings. I wonder if this also applies to reversing?

Sure, the brush shift is incorrect when rotation is reversed. But for vehicle reverse (opposed to regeneration), motor voltage, current and RPM are typically low. Backing up an incline can cause comm burning.