D-Component
CMLDBLU1
CMLDBLU2
Vstall > Vbrk
Eg. 0.9 > 0.86
Considered a data error and this instance of CMLD
Model is not applied.
Considered a data error and this instance of CMLD
Model is not applied.
Vstallbrk > Vbrk
Eg. 0.9 > 0.86
Vstallbrk not programed.
Considered a data error and this instance of CMLD
Model should not be applied.
NOT CHECKED – We need to make sure software
vendors are checking for this data error.
Vbrk > Vstall > Vstallbrk
Eg. 0.86 > 0.65 > 0.55
As voltage goes down, trajectory transitions
immediately from run curve to stall curve once userentered Vstall is reached (may result in a step transient
if Vstall is not at intersection of run and stall curves and
may result in numerical instability if Vstall is below
intersection). Transition is not delayed by Tstall though
Tstall timer begins timing.
As voltage goes down, trajectory transitions from run
curve to stall curve once user-entered Vstall is reached
and user-entered Tstall timer times out (may result in a
step transient). However, if intersection point between
run and stall curves (at Vstallbrk) is reached before
Tstall timer times out, transition to stall curve happens
immediately and without delay, even if Tstall timer has
not timed out. Trajectory continues down stall curve as
voltage continues to go down.
Depending on whether Tstall timer has timed out while
voltage has existed below Vstall leads to two
possibilities as voltage recovers:
1. Tstall timer does not time out. As voltage goes up
with model in an “unofficial” stall mode, trajectory
of 100 percent of D-component transitions from
stall curve to run curve once Vstall(?) is reached.
There is no delay in transition and Tstall, Trestart,
Frst, and Vrst are not applicable.
2. Tstall timer does time out. As voltage goes up with
model now in “official” stall mode and once
trajectory reaches Vrst, Trestart timer begins timing
and Frst fraction of D-component transitions from
stall curve to run curve once Trestart timer times
out. (Vstall should be <= Vrst) Remaining fraction
Depending on whether Tstall timer has timed out while
voltage has existed below Vstall leads to two
possibilities as voltage recovers (the two conditions are
shown graphically):
1. Tstall timer does not time out. As voltage goes up
with model in an “unofficial” stall mode, trajectory
of 100 percent of D-component transitions from
stall curve to run curve once Vstallbrk intersection
point is reached. There is no delay in transition and
Tstall, Trestart, Frst, and Vrst are not applicable.
2. Tstall timer does time out. As voltage goes up with
model now in “official” stall mode and once
trajectory reaches Vrst, Trestart timer begins timing
of D-component load remains in stall mode until
heating logic possibly removes it.
Vbrk > Vstallbrk > Vstall
Eg. 0.86 > 0.55 > 0.2
One factor to consider here
is contactor drop out. For
the example thresholds
given above, Motor D will
drop out before reaching
0.2pu stall threshold. The
contactor drop out is
around 0.5pu.
(Same as above; Vstallbrk not programmed)
and Frst fraction of D-component transitions from
stall curve to run curve once Trestart timer times
out. (Vstall should be <= Vrst) Remaining fraction
of D-component load remains in stall mode until
heating logic possibly removes it.
As voltage goes down, trajectory immediately
transitions from run curve to stall curve once
intersection point at Vstallbrk is reached. There is no
delay in transition and Tstall is not applicable in this
transition. However, Tstall timer will still begin timing
once voltage drops below Vstall, and if Tstall timer
times out while voltage remains below Vstall, model
will “officially” enter stall mode. Note that we are still
on stall curve.
This then leads to same two possibilities as voltage
recovers:
1. Tstall timer does not time out. As voltage goes up
with model in an “unofficial” stall mode, trajectory
of 100 percent of D-component transitions from
stall curve to run curve once Vstallbrk intersection
point is reached. There is no delay in transition and
Tstall, Trestart, Frst, and Vrst are not applicable.
2. Tstall timer does time out. As voltage goes up with
model now in “official” stall mode and once
trajectory reaches Vrst, Trestart timer begins timing
and Frst fraction of D-component transitions from
stall curve to run curve once Trestart timer times
out. (Vstall should be <= Vrst) Remaining fraction
of D-component load remains in stall mode until
heating logic possibly removes it.
Vbrk > Vstall > Vstallbrk
or
Vbrk > Vstallbrk > Vstall
Contactors and UV Relays
Section of run curve below intersection of run and stall
curves is applicable if Vstall < intersection voltage
(Vstallbrk).
Section of run curve below Vstallbrk is not applicable;
model can never get there. That’s correct, the model
will never be on the run characteristic below Vstallbrk.
If either UV relay causes a trip, the specified fraction, Fuvr, is removed regardless of whether D-component is in
run or stall mode. Same with contactors causing a trip except that 100 percent of D-component is removed.
As voltage goes back up, there is no restoration from any prior UV relay tripping. Contactors restore a Dcomponent previously in run mode to run mode, or a D-component previously in stall mode, whether official or
unofficial, to stall mode (with exception to follow). If contactor has been out for some time, model does NOT
consider possibility of D-component having stalled if it had been in run mode upon contactor drop out.
To repeat, if D-component was in stall mode upon contactor drop out, contactor returns it in stall mode.
EXCEPTION: if contactor reclosing occurs above Vstall and Vstallbrk, D-component is returned on run curve if the
mode had been unofficial stall mode (Tstall not timed out).
Conversely, D-component is returned on stall curve if mode had transitioned to official stall mode by Tstall timer
having timed out, even if voltage is above Vstall and Vstallbrk. Note: Tstall timer continues to time while voltage is
below Vstall, even while contactor is out. As voltage goes above Vrst, restartable fraction restarts once Trestart
timer times out. D-component is now split into Frst and 1-Frst fractions, Frst on run curve, 1-Frst on stall curve.
Commented [GA1]: This needs to be verified. I am not
sure how vendors are implementing the logic of connecting
back Motor D once the contactor recloses.
Commented [GA2]: I agree. We need to make sure the
vendors are following this
Commented [GA3]: I agree. Again, we need to confirm if
the vendors are following this.