Danfoss VLT AQUA Drive FC 200 Programming Manual page 52

Parameter Description
(direction). If unable to find the speed, it will search in the
other direction. If not successful, a DC brake will be
activated in the time set in 2-02 DC Braking Time. Start will
then take place from 0 Hz.
3 3
The Flystart function used for PM motors is based on an
initial speed estimation. The speed will always be
estimated as the first thing after an active start signal is
given. Based on the setting of 1-70 PM Start Mode, the
following will happen:
1-70 PM Start Mode = [0] Rotor Detection:
If the speed estimate comes out as greater than 0 Hz, the
adjustable frequency drive will catch the motor at that
speed and resume normal operation. Otherwise, the
adjustable frequency drive will estimate the rotor position
and start normal operation from there.
1-70 PM Start Mode = [1] Parking:
If the speed estimate comes out lower than the setting in
1-59 Flystart Test Pulses Frequency, then the Parking
function will be engaged (see 2-06 Parking Current and
2-07 Parking Time). Otherwise, the adjustable frequency
drive will catch the motor at that speed and resume
normal operation. Refer to description of 1-70 PM Start
Mode for recommended settings.
Current limitations of the Flystart Principle used for PM
motors:
•
The speed range is up to 100% Nominal Speed or
the field weakening speed (which ever is lowest).
•
PMSM with high back emf (>300 VLL(rms)) and
high winding inductance (>10 mH) needed more
time for reducing short circuit current to zero 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 3 HP [2.2
kW] and all 380‒480 V units up to and including
5.4 HP [4 kW].
•
Current testing limited to a machine power size
up to 30 HP [22 kW].
•
Prepared for salient pole machine (IPMSM) but
not yet verified on those types of machine.
•
For high inertia applications (i.e., 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 Flystart function.
3-26
®
VLT AQUA Drive Programming Guide
1-74 Start Speed [RPM]
Range:
Size related
1-75 Start Speed [Hz]
Range:
Size
related
1-76 Start Current
Range:
0 A
*
3.3.9 1-8* Stop Adjustments
1-80 Function at Stop
Option:
[0] Coast Leaves motor in free mode.
1-81 Min Speed for Function at Stop [RPM]
Range:
Size related
®
MG20O622 - VLT is a registered Danfoss trademark
Function:
[0 - 600 Set a motor start speed. After the
*
RPM] start signal, the output speed leaps to
set value. Set the start function in
1-72 Start Function and set a start
delay time in 1-71 Start Delay.
Function:
[ 0 - This parameter can be used for hoist
500.0 Hz] applications (cone rotor). Set a motor
*
start speed. After the start signal, the
output speed leaps to set value. Set the
start function in 1-72 Start Function and
set a start delay time in 1-71 Start Delay.
Function:
[ 0 - par. Some motors, e.g., cone rotor motors, need
1-24 A] extra current/starting speed to disengage the
rotor. To obtain this boost, set the required
current in 1-76 Start Current. Set 1-74 Start
Speed [RPM]. Set 1-72 Start Function to [0] DC
Hold/Motor Preheat, and set a start delay time
in 1-71 Start Delay.
Function:
Select the adjustable frequency drive function after a
stop command or after the speed is ramped down to
the settings in 1-81 Min Speed for Function at Stop
[RPM].
Available selections depend on 1-10 Motor
Construction:
[0] Asynchron:
[0] coast
[1] DC hold
[1] PM non-salient:
[0] coast
[0 - 600 RPM]
*
Function: