Start Mode - ABB ACS355 series User Manual

Appendix: Permanent magnet synchronous motors (PMSMs) 433

Start mode

The default value of parameter
this is suitable for starting the rotation. If fast start with low inertia is required, it is
recommended to set parameter
Smooth start
The Smooth start function can be used if the motor is not able to start or when
rotation at low speeds needs to be improved. The following table lists the needed
parameter settings.
No. Name
2621 SMOOTH
START
2622 SMOOTH
START
CUR
2623 SMOOTH
START
FRQ
Speed controller tuning
In vector control mode, it is recommended to tune the speed controller. In
applications where the motor can be rotated freely, automatic tuning can be used.
See parameter 2305 AUTOTUNE RUN
Usually it is enough to adjust the proportional gain (parameter
the speed controller to a higher value. The default value is 5 which results in rather
conservative speed controller tuning. Increase the proportional gain value by 5 until
the performance is satisfactory. If the application becomes unstable, divide the last
gain value by 2, and you have reached rather robust speed controller tuning.
Note: It is recommended to use encoder feedback if accurate torque control, high
torque production, or sustained operation is required at low speeds (below 20% of the
motor nominal speed).

Adjusting motor speed estimation gain in case of an over current
failure
The inertia of the PM motor application may cause over current trips. If the drive fails
constantly to over current with the PM motor (Fault 01), the speed estimation gain
may need to be adjusted. This is done by changing the parameter
BW TRIM.
2101 START FUNCTION
2101 START FUNCTION
Value Description
0 Disabled
1 Enabled always
2 Start only
10...100% Current applied to the motor when the Smooth start
is active. Increasing the current helps enable starting
with a load or with a large inertia. Decreasing the
current can prevent the rotor from turning into a
wrong direction during the start.
2...100% Set the smooth start frequency range as small as
possible. This should be tuned so that the rotation is
stable throughout the whole speed range.
is 1 (AUTO). In most cases
to 2 (DC MAGN).
for more information.
Default
0
50%
10%
2301 PROP GAIN) of
2626 SPD EST