Appendix C – Examples
C-2 ACS 600 Master/Follower Application Macro
Example 2: Master and Follower are not coupled fixedly.
To equalise the load between the Master and the Follower, they are controlled with the same
speed reference. Torque control of the Follower cannot be used due to varying friction of the belt
driven; a sudden fall in friction of the follower wheel would cause the motor to rush as the drive
would be trying to retain a certain torque level. Drooping should be used to ensure smooth oper-
ation and even load distribution between the Master and the Follower.
Parameter settings of the Master:
- See the default settings of the M/F Application macro in
Appendix B – Parameter Settings
.
Parameter settings of the Follower:
- See the Follower Speed Control settings in
Appendix B – Parameter Settings.
Exception: Parameter 60.06 DROOP RATE is set to 1%.
Operation:
The Follower follows the same speed reference as the Master (SPEED REF 3). Drooping
ensures even load distribution in all operating conditions. An example:
– Friction under the follower wheel drops, causing slipping. The torque is decreased to prevent
the speed rise.
– The load of the master increases -> Internal torque reference increases to keep the speed
constant -> Drooping in the Master increases -> Speed decreases slightly.
– The Follower now runs a little faster than the Master. When the friction returns to normal, the
Follower load increases, causing a rise in the internal torque reference. Drooping in the Fol-
lower increases -> Follower actual speed decreases. The Master load increases. This cycle is
repeated until the balance is regained.
The Run enable signal to the master is wired through Relay Output RO3 of the Follower. By
default, RO3 switches off the Run enable signal upon a Follower fault or power loss.
Example 2: Master and Follower Drives Coupled Flexibly to Each Other
I/O
ACTUAL SPEED
–
+
I/O
LO RE R E
RE
AC PA FU DRI
EN
0 L 1242.0 rpm I
FREQ 45.00 Hz
CURRENT 80.00 A
TO MASTER
ACS 600 Master
ACS 600 Follower
+24 V DC
NO FAULT (RO3)
RUN ENABLE (DI6)
TO FOLLOWER
0
2
0
3
4
5
PID
=
~
Inverter
2.02
SPEED REF 3
SPEED
CONTROLLER
TORQUE REFER-
ENCE SELECTOR
TORQUE REFER-
ENCE CONTROL
2.13
TORQ REF USED
INVERTER
CONTROL
2.09
TORQ REF 2
2.10
TORQ REF 3
SPEED
TORQUE
MIN
MAX
ADD
–
+
0
2
0
3
4
5
PID
=
~
Inverter
SPEED
CONTROLLER
TORQUE REFER-
ENCE SELECTOR
TORQUE REFER-
ENCE CONTROL
INVERTER
CONTROL
2.09
TORQ REF 2
2.10
TORQ REF 3
SPEED
TORQUE
MIN
MAX
ADD
2.02
SPEED REF 3
ACTUAL SPEED
2.13
TORQ REF USED
START/STOP
DIRECTION
RUN ENABLE
FAULT RESET
EXTERNAL
CONTROL
SIGNALS
EXTERNAL
SUPERVISION
SIGNALS
–
+
DROOP
RATE
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