ABB ACSM1 - Page 190

Parameters and firmware blocks
190
40.03 SLIP GAIN FW block: MOTOR CONTROL (see above)
Defines the slip gain which is used to improve the estimated motor slip. 100% means full slip gain; 0%
means no slip gain. The default value is 100%. Other values can be used if a static speed error is
detected despite of the full slip gain.
Example (with nominal load and nominal slip of 40 rpm): A 1000 rpm constant speed reference is
given to the drive. Despite of the full slip gain (= 100%), a manual tachometer measurement from the
motor axis gives a speed value of 998 rpm. The static speed error is 1000 rpm - 998 rpm = 2 rpm. To
compensate the error, the slip gain should be increased. At the 105% gain value, no static speed error
exists (2 rpm / 40 rpm = 5%).
0…200% Slip gain.
40.04 VOLTAGE RESERVE FW block: MOTOR CONTROL (see above)
Defines the minimum allowed voltage reserve. When the voltage reserve has decreased to the set
value, the drive enters the field weakening area.
If the intermediate circuit DC voltage U
dc
= 550 V and the voltage reserve is 5%, the RMS value of the
maximum output voltage in steady-state operation is
0.95 × 550 V / sqrt(2) = 369 V
The dynamic performance of the motor control in the field weakening area can be improved by
increasing the voltage reserve value, but the drive enters the field weakening area earlier.
-4…50% Minimum allowed voltage reserve.
40.05 FLUX OPT FW block: MOTOR CONTROL (see above)
Enables the flux optimisation function. Flux optimisation improves motor efficiency and reduces noise.
Flux optimisation is used in drives that usually operate below nominal load.
Note: With a permanent magnet motor, flux optimisation is always enabled regardless of this
parameter.
(0) Disable Flux optimisation disabled.
(1) Enable Flux optimisation enabled.
40.06 FORCE OPEN LOOP FW block: MOTOR CONTROL (see above)
Defines the speed/position information used by the motor model.
(0) FALSE Motor model uses the speed feedback selected by parameter 22.01
SPEED FB SEL.
(1) TRUE Motor model uses the internal speed estimate (even when parameter
22.01 SPEED FB SEL setting is (1) Enc1 speed / (2) Enc2 speed).