The below message from Bill D. is interesting and points out the loss stack up quite clearly. I use a PM100 (Rinehart Motion, now Cascadia Motion) inverter with an induction motor (Ford ranger EV Siemens surplus). The up side of the PM100 using the simple state machine mode and the direct throttle pot inputs is that I have complete control over the torque command curve, including the addition of a 'dead' band in the throttle input which with a little practice allows me to coast with no torque command. I've programmed the band to be very narrow so as not to lose too much throttle travel range, but it is possible to hold the throttle steady and simply coast along which is particularly good on level ground. The down side of this arrangement is that there is no wind up torque being applied to the Borg Warner T5 transmission (US Electricar S10) which allows the gear train to rattle back and forth until I let up or increase the throttle position.
Paul Wallace Message: 3 Date: Tue, 4 Jan 2022 22:40:38 +1300 From: Bill Dube <[email protected]> To: [email protected] Subject: [EVDL] Regen toll (was: Tesla Y actual wall outlet efficiency) Message-ID: <[email protected]> Content-Type: text/plain; charset=UTF-8; format=flowed With an AC drive, there is no excuse not to use regen. It is built in, and essentially free. At least equipment wise. Regen has significant energy losses, however, so you should use it sparingly, or at least knowledgeably. Typical EV drivetrain losses are in the ~15% range, give or take. Whatever the drivetrain losses, they at least double when you regeneratively brake. You first pay that ~15% toll on the way out of the battery, through the controller, through the motor, and to the pavement. Then you pay the toll once more pulling that same energy from the pavement, through the motor, through the controller, and pushing it back into the battery. You basically pay twice the toll, or perhaps 30%, to recover the energy with regen. You don't get all the energy back. If you drive a bit more conservatively, you can avoid expending that energy extra energy in the first place, and then recovering that energy, and paying the regen toll. Not quite as much fun, but you can perhaps actually get where you plan to go. :-) ??? Bill D. On 1/4/2022 2:12 PM, John Lussmyer via EV wrote: > On Mon Jan 03 15:02:46 PST 2022 [email protected] said: >> On 3 Jan 2022 at 12:09, (-Phil-) via EV wrote: >> For decades EV hobbyists dismissed regen as not worth the extra effort to >> implement. "Just add another battery or two," they said. >> >> That's a pragmatic answer when you've chosen a series DC motor, which is >> really tough to use for regen. But in fact, under the right circumstances, >> regen is like leveling out the hills. > Yup, and it REALLY depends on where you are driving. > 95% of my trips are here on Whidbey Island. Yes there are hills - but they > are gentle, and there is only one where I gain a little speed. > So the only use for Regen is when I stop - and almost all of my driving is on > a highway with only about 3 traffic lights per trip, which aren't always > stops. > > Regen wouldn't give back very much in my situation. > > > -- > > Worlds only All Electric F-250 truck! > http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 > _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
