ABB ACS 800 Series, Firmware Manual

Page: 204 / 340

Actual signals and parameters
204
60.06 DROOP RATE Defines the droop rate. The parameter value needs to be changed only if both
the Master and the Follower are speed-controlled:
- External control location 1 (EXT1) is selected (see parameter
11.02 or
- External control location 2 (EXT2) is selected (see parameter 11.02 ) and
parameter 60.02 is set to SPEED.
The droop rate needs to be set both for the Master and the Follower. The
correct droop rate for a process must be found out case by case in practice.
The drooping prevents a conflict between the Master and the Follower by
allowing a slight speed difference between them. The drooping slightly
decreases the drive speed as the drive load increases. The actual speed
decrease at a certain operating point depends on the droop rate setting and
the drive load ( = torque reference / speed controller output). At 100% speed
controller output, drooping is at its nominal level, that is equal to the value of
the DROOP RATE. The drooping effect decreases linearly to zero along with
the decreasing load.
0 … 100% Droop rate in percent of the motor nominal speed. 0 … 1000
60.07 MASTER SIGNAL 2 Selects the signal that is sent by the Master to the Follower(s) as Reference 1
(speed reference).
0000 … 9999 Parameter index 0000 …
9999
60.08 MASTER SIGNAL 3 Selects the signal that is sent by the Master to the Follower(s) as Reference 2
(torque reference for load sharing or speed reference for Shaft
synchronisation).
Note : This has to be set to 202 when the Par. 60.11 is set as SPEED and has
to be set 213 when the Par. 60.11 is set as TORQUE.
0000 … 9999 Parameter index 0000 …
9999
60.09 LOAD SHARE Selects the scaling factor in percentage of the signal that is sent by the Master
to the Follower(s) as
Reference 2 (torque reference). Active only in Follower
drives.
0.... 400 % Percentage 0.... 400
60.10 NO OF SLAVES Selects the number of slaves when the drive is selected as the Master. Active
only if selected as Master.
1.... 4 Setting range 1.... 4
Index Name/Selection Description FbEq
Motor
Speed
% of
nominal
Drooping
No Drooping
Speed Controller
100%
} Par. 60.06 DROOP RATE
Output / %
Speed Decrease =
Speed Controller Output · Drooping · Max. Speed
Example: Speed Controller output is 50%, DROOP RATE is
1%, maximum speed of the drive is 1500 rpm.
Speed decrease = 0.50 × 0.01 × 1500 rpm = 7.5 rpm
Drive load
100%