ABB ACS350 Series, User Manual

Page: 191 / 314

Actual signals and parameters
191
2304 ACC
COMPENSATION Defines the derivation time for acceleration/(deceleration) compensation. In
order to compensate inertia during acceleration a derivative of the reference
is added to the output of the speed controller. The principle of a derivative
action is described for parameter
2303 DERIVATION TIME.
Note: As a general rule, set this parameter to the value between 50 and
100% of the sum of the mechanical time constants of the motor and the
driven machine. (The speed controller Autotune Run does this automatically,
see parameter
2305 AUTOTUNE RUN.)
The figure below shows the speed responses when a high inertia load is
accelerated along a ramp.
0
0.00…600.00 s Time 1 = 0.01 s
2305 AUTOTUNE RUN Start automatic tuning of the speed controller. Instructions:
- Run the motor at a constant speed of 20 to 40% of the rated speed.
- Change the autotuning parameter 2305 to ON.
Note: The motor load must be connected to the motor.
OFF
OFF No autotuning 0
ON Activates the speed controller autotuning. The drive
- accelerates the motor.
- calculates values for proportional gain, integration time and acceleration
compensation (parameter
2301 PROP GAIN, 2302 INTEGRATION TIME and
2304 ACC COMPENSATION values).
Setting is automatically reverted to OFF.
1
24 TORQUE CONTROL Torque control variables
2401 TORQ RAMP UP Defines the torque reference ramp up time, i.e the minimum time for the
reference to increase from zero to the nominal motor torque. 0
0.00…120.00 s Time 1 = 0.01 s
2402 TORQ RAMP DOWN Defines the torque reference ramp down time, i.e the minimum time for the
reference to decrease from the nominal motor torque to zero. 0
0.00…120.00 s Time 1 = 0.01 s
Parameters – complete descriptions
Index Name/Selection Description Def, FbEq
Speed reference
Actual speed
* No acceleration compensation
Acceleration compensation
t
t
%
%