The controller doesn't determine the rate of change of current, it determines the applied voltage. If you take a controller that expects 100uH and give it 50mH, the current will just change more slowly. The controller can't apply extra voltage to force the current to change more quickly, it just applies pack voltage at some duty cycle.
The only potential issue I could see is that the control loop probably isn't tuned for so much inductance, but I think that would just increase stability and slow response time. The control loop's anti-windup would prevent significant overshoot. Even regular motors have enough inductance that the current basically doesn't change while switching the transistors, so they already have to deal with inductive kick while switching. Morgan LaMoore On Aug 14, 2013 2:36 AM, <[email protected]> wrote: > Lee I agree some inductance is good for a controller -- but surely it's > possible to have too much? > > The truck motor weighs 2600 lbs. That's 15 Kostov sepex motors worth of > weight. If you tried to ramp up or ramp down the current faster than the LR > time constant, might it not spike the voltage high enough to hurt > something? Just intuitively, it seems 15 Kostovs in series would give a > controller designed for a single motor problems -- or is there an error in > my thinking and a controller can handle 15x inductance? Another way to ask > the question is what's the fastest safe rate for changing current as a > function of inductance? Would you have to slew 15x slower if you have 15x > the inductance? > ----- Original Message ----- > From: Lee Hart > Sent: 08/13/13 12:37 PM > To: Electric Vehicle Discussion List > Subject: Re: [EVDL] S.E.P.X . controller for 500V , 450Amp Motor > ... > > [email protected] wrote: > A car controller might not be able to > handle so much > inductance unless you ramped the current very slowly. > Inductance is the *friend* of motor controllers! They *like* high > inductance; in fact, they have trouble when there isn't *enough* inductance. > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130814/32c300b2/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130814/6a81a514/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
