ABB PSTX30 Installation And Commissioning Manual page 73

7.2.2 Torque stop ramp
When using the Torque stop ramp, the output voltage
to the motor is controlled so that the torque will follow
a predefined optimal curve from the Step down level to
end voltage during stop. This has the benefit that the
mechanical stopping behaviour of the equipment driven
by the motor, will be much softer than when using voltage
ramp. See Figure 81.
This can be especially useful in pump applications where
a sudden stop can cause water hammering and pressure
surges.
Torque stop ramp is configured with the following
parameters:
Parameter
02.02 Stop mode
02.05 Stop ramp end level
02.06 Stop ramp time
28.05
Step down level
28.07 Torque finish
28.08 Torque tune
28.09 Torque ctrl gain
28.10 Torque PI intergration time
28.11 Torque slip
28.12 Torque diff
28.13
Torque filter time
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81
Figure 81: Torque stop ramp
Description
Set to Torque ramp.
Sets the level from where the stop ramp ends and
the power to the motor is cut(voltage level for Voltage
stop and torque level for Torque stop.
Sets the time it takes for the voltage to reach end
level.
Sets the level from where the stop ramp initiates.
Sets the operational torque for Torque start ramp
settings in percentage of base torque.
Sets the adjustment of resistive losses.
Sets the speed of the voltage regulator during torque
start and stop. It seldom needs to be changed, but if
a dip occur in the torque curve during stop, increasing
this value might solve it.
Sets the integration time of PI controller.
Sets the slip difference from nominal to pull-out
torque in percentage.
Sets the maximum desired difference between
reference and actual torque in percentage.
Sets the Torque control filter time in seconds.
U
Stop Time
rpm
Stop Time
Setting range
No ramp,
Voltage stop
ramp, Torque
stop ramp
10 ... 99%
1 ... 120 s
10 ... 100 %
30...500%
0...1000%
0.01 ... 10
0.001 ... 10 s
0.1 ... 100 %
0.1 ... 100 %
0.01 ... 10 s
7
Default value
No ramp
30%
10 s
80 %
100%
100%
0.04
0.002 s
1.0 %
2.0 %
0.02 s