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8461Re: [solectria_ev] Controller delta vs WYE [was Re: Upgrade voltage - DC-DC Converter ...]

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  • Wolf
    Oct 27, 2012
      It is more basic than that, with out adjusting for the inductance change
      from DELTA to WYE the pwm current wave form will start to look triangular,
      instead of sinusoidal.

      Or more square if going from WYE to DELTA...

      You want a nice prefect sinewave for the most efficient transfer of power
      to the rotor.
      On Oct 27, 2012 2:10 PM, "Lawrence Winiarski" <lawrence_winiarski@...>
      wrote:

      > **
      >
      >
      > Just lurking and not a motor expert, but wouldn't the lag of the phasor
      > (and of course the total current) depend more heavily on the slip?
      > I'd think the actual reactive inductance varies all over the place as the
      > car goes up and down hills and shifts from power => regen.
      >
      > Not saying the static inductance doesn't matter, but curious how much the
      > phasor angle varies from the static position.
      >
      > ----------------------------------------------------------
      > If we don't halt population growth with justice and compassion, it will be
      > done for us by nature, brutally and without pity - and will leave a ravaged
      > world.
      > Nobel Laureate Dr. Henry W. Kendall 023934
      >
      > ________________________________
      > From: geo_homsy2 <geo.homsy@...>
      > To: solectria_ev@yahoogroups.com
      > Sent: Saturday, October 27, 2012 11:14 AM
      > Subject: [solectria_ev] Controller delta vs WYE [was Re: Upgrade voltage -
      > DC-DC Converter ...]
      >
      >
      >
      > Ahaa! Thanks, Wolf!
      >
      > --- In solectria_ev@yahoogroups.com, Wolf <wolf@...> wrote:
      > >
      > > The controller cares because the motor has twice the inductance when
      > wired
      > > in WYE, thus the phasor needs to be advanced to counteract the lagged
      > > current.
      > > On Oct 26, 2012 1:26 AM, "geo_homsy2" <geo.homsy@...> wrote:
      > >
      > > > **
      > > >
      > > >
      > > > Hi Josh-
      > > >
      > > > I'm familiar with phasor analysis, and I understand the difference
      > between
      > > > a motor wired delta, and a motor wired wye. I like to think of it as
      > > > changing the voltage- and current- constants of the motor, by a factor
      > of
      > > > sqrt(3) = 1.73, as you said.
      > > >
      > > > What I do NOT understand, however, is why the controller cares! Phases
      > R,
      > > > S, and T, should be basically the same, but 120 degrees out of phase.
      > > > Period, end of story. I don't know why the controller wants to know the
      > > > topology of what it's driving, as long as it's 3-fold symmetric.
      > > >
      > > > You had me confused with "I'm guessing that the controller was 'smart'
      > and
      > > > outputting 2 full power outputs, and 1 low voltage, like it should for
      > > > WYE." I'm still confused by that. As you and I both said, all three
      > outputs
      > > > should be roughly the same but phase-shifted.
      > > >
      > > > Yours,
      > > >
      > > > //Geo
      > > >
      > > > --- In solectria_ev@yahoogroups.com, "otedawg" <joshua.orfield@>
      > wrote:
      > > > >
      > > > > Geo,
      > > > > Of course I can help out. I didn't know all of this till recently,
      > but I
      > > > am a EE and I have worked with power systems, but not motors before.
      > > > >
      > > > > I guess I'll start with Delta. Simply put, Delta is a motor wired in
      > the
      > > > shape of a delta (triangle). The controller outputs the same voltage
      > on all
      > > > three posts, and the motor runs in the correct direction based on the
      > > > phasing of the wires. A 156V delta 3 phase system runs the 3 points of
      > the
      > > > triangle at a total of 78V to ground, and 156V across for phase A-B,
      > B-C, &
      > > > C-A. Phase: A is at 0degrees, B is at 120degrees, and C is at
      > 240degrees.
      > > > >
      > > > > A WYE or Y motor is wired in the shape of a Y (hence the name). To
      > > > control this motor, the controller runs similarly, but the voltage
      > across
      > > > each leg of the Y motor is lowered. (After EE magic, that number is
      > 1.73).
      > > > >
      > > > > I'm not sure if I've explained or obfuscated the issue there. You've
      > got
      > > > to wrap your mind around the fact that there are 3 different voltage
      > > > application locations, keep in mind that power is conserved (A delta
      > motor
      > > > will have it's current divided by 1.73, but a Y motor will have the
      > voltage
      > > > divided by 1.73), and stare at it long enough.
      > > > >
      > > > > Equations: http://www.watlow.com/reference/equations/0101.cfm
      > > > > Motor Depictions:
      > http://www.firstelectricmotor.com/images/motcon9.jpg
      > > > >
      > > > > Hopefully that's helpful.
      > > > >
      > > > > Thanks,
      > > > > Josh
      > > > >
      > > > >
      > > > >
      > > > > --- In solectria_ev@yahoogroups.com, "geo_homsy2" <geo.homsy@>
      > wrote:
      > > > > >
      > > > > > Hi Josh-
      > > > > >
      > > > > > question for you: You seem to know how the controller differs in
      > its
      > > > drive characteristics when it's configured for delta or for wye. Can
      > you
      > > > elucidate that for me, and for the other group members?
      > > > > >
      > > > > > I would've just assumed symmetric drive in both cases, and that's
      > why
      > > > I've never been able to understand WHY the controller has a setting for
      > > > delta vs. wye.
      > > > > >
      > > > > > yours,
      > > > > >
      > > > > > //Geo
      > > > > >
      > > > > > --- In solectria_ev@yahoogroups.com, "otedawg" <joshua.orfield@>
      > > > wrote:
      > > > > > >
      > > > > > > I have switched the motor from wye to delta, and back and forth
      > when
      > > > I was trying to test it. I'm confident that I've done it right. I even
      > > > tested the leads to make sure the labeling is correct. I think that my
      > > > problem was the .par file - I'm guessing that the controller was
      > 'smart'
      > > > and outputting 2 full power outputs, and 1 low voltage, like it should
      > for
      > > > WYE.
      > > > > > >
      > > > > > > I'm hoping that's the problem.
      > > > > > >
      > > > > > > Thanks,
      > > > > > > Josh
      > > > > > >
      > > > > > > --- In solectria_ev@yahoogroups.com, Collin Kidder <collink@>
      > wrote:
      > > > > > > >
      > > > > > > > The parameter file can now be found here:
      > > > > > > >
      > > > > > > > http://www.kkmfg.com/PAR-10-1631-0007_SO1083.par
      > > > > > > >
      > > > > > > > As I had mentioned, I went from delta to wye with a car. I got
      > a
      > > > new CCS
      > > > > > > > and PAR file and I had to open the motor housing and switch
      > around
      > > > wires on
      > > > > > > > terminals. The motor can be switched from delta to wye and
      > back by
      > > > > > > > loosening nuts and moving wires in the motor. Have you done
      > that?
      > > > > > > >
      > > > > > > > On Wed, Oct 24, 2012 at 12:33 PM, otedawg <joshua.orfield@>
      > wrote:
      > > > > > > >
      > > > > > > > > **
      > > > > > > > >
      > > > > > > > >
      > > > > > > > > Collin,
      > > > > > > > > Thanks for that - I'll try downloading and running with this
      > > > file when I
      > > > > > > > > get home today... And I just realized that I need the
      > parameter
      > > > (.par)
      > > > > > > > > file, not the .ccs file. Could you upload such a file? Sorry
      > for
      > > > the
      > > > > > > > > inconvenience.
      > > > > > > > >
      > > > > > > > > Hopefully the wye -> delta conversion is just a parameter
      > > > change, not
      > > > > > > > > something hidden that Azure uses...
      > > > > > > > >
      > > > > > > > > Thanks,
      > > > > > > > > Josh
      > > > > > > > >
      > > > > > > > >
      > > > > > > > >
      > > > > > > >
      > > > > > > >
      > > > > > > > [Non-text portions of this message have been removed]
      > > > > > > >
      > > > > > >
      > > > > >
      > > > >
      > > >
      > > >
      > > >
      > >
      > >
      > > [Non-text portions of this message have been removed]
      > >
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >


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