Danfoss VLT AQUA Drive FC 202, Programming Manual, Page: 59 / 294

1-73 Flying Start
Option: Function:
•
Parameter 2-07 Parking Time .
When parameter 1-73 Flying Start is enabled,
parameter 1-71 Start Delay has no function.
The flying start function used for PM motors is based on
an initial speed estimation. The speed is always estimated
immediately after an active start signal is given. Based on
the setting of
parameter 1-70 Start Mode , the following
happens:
Parameter 1-70 Start Mode = [0] Rotor Detection :
If the speed estimate comes out as higher than 0 Hz, the
frequency converter catches the motor at that speed and
resumes normal operation. Otherwise, the frequency
converter estimates the rotor position and starts normal
operation from there.
Parameter 1-70 Start Mode = [1] Parking :
If the speed estimate comes out lower than the setting in
parameter 1-59 Flying Start Test Pulses Frequency , the
parking function is engaged (see parameter 2-06 Parking
Current and parameter 2-07 Parking Time ). Otherwise, the
frequency converter catches the motor at that speed and
resumes normal operation. Refer to the description of
parameter 1-70 Start Mode for recommended settings.
Current limitations of the flying start principle used for PM
motors:
•
The speed range is up to 100% nominal speed or
the field weakening speed (whichever is lowest).
•
PMSM with high back EMF (>300 VLL(rms)) and
high-winding inductance (>10 mH) needs more
time for reducing short-circuit current to 0 and
may be susceptible to error in estimation.
•
Current testing limited to a speed range up to
300 Hz. For certain units, the limit is 250 Hz; all
200–240 V units up to and including 2.2 kW
(3 hp) and all 380–480 V units up to and
including 4 kW (5.4 hp).
•
Current testing limited to a machine power size
up to 22 kW (30 hp).
•
Prepared for salient pole machine (IPMSM) but
not yet verified on those types of machine.
•
For high-inertia applications (where the load
inertia is more than 30 times larger than the
motor inertia), a brake resistor is recommended
to avoid overvoltage trip during high-speed
engagement of the flying-start function.
1-79 Pump Start Max Time to Trip
Range: Function:
0 s
*
[ 0 -
3600.0 s] If the motor does not reach the speed specified
in
parameter 1-86 Trip Speed Low [RPM] within
the time specified in this parameter, the
frequency converter trips. The time in this
parameter includes the time specified in
parameter 1-71 Start Delay . For instance, if the
value in parameter 1-71 Start Delay is more or
equal to the value in parameter 1-79 Pump Start
Max Time to Trip , the frequency converter never
starts.
3.3.12 1-8* Stop Adjustments
1-80 Function at Stop
Option: Function:
Select the frequency converter function after
a stop command or after the speed is
ramped down to the settings in
parameter 1-81 Min Speed for Function at Stop
[RPM]
.
Available selections depend on
parameter 1-10 Motor Construction :
[0] Asynchron :
•
[0] Coast .
•
[1] DC hold .
[1] PM non-salient :
•
[0] Coast .
[0]
*
Coast Leaves the motor in free mode.
[1] DC Hold/
Motor
Preheat Energizes the motor with a DC hold current
(see
parameter 2-00 DC Hold/Preheat Current ).
[2] Motor
check,
warning
[6] Motor
check, alarm
1-81 Min Speed for Function at Stop [RPM]
Range: Function:
Size related
*
[0 - 600
RPM] Set the speed at which to activate
parameter 1-80 Function at Stop .
1-82 Min Speed for Function at Stop [Hz]
Range: Function:
Size related
*
[ 0 - 20.0
Hz] Set the output frequency at which to
activate
parameter 1-80 Function at
Stop .
Parameter Description Programming Guide
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