Functions
8.24 Open-loop and closed-loop control
Control Units CU240S
Operating Instructions, 11/2006, A5E00766042B AA
8-175
8.24.2.3 Speed controller
Data
P1300, P1400 … P1780
SLVC: P1470, P1472, P1452
Parameter range:
VC: P1460, P1462, P1442
Warnings: -
Faults: -
Function chart number: FP7500, FP7510
Description
Both of the control techniques (SLVC and VC) have the same speed controller structure
which includes the following components:
● PI controller
● Speed controller pre-control
● Droop
The sum of the output quantities forms the speed setpoint, which is reduced to the
permissible level using the torque setpoint limiting function.
Speed controller (SLVC: P1470, P1472, P1452 VC: P1460, P1462, P1442)
The speed controller (see figure below) receives its setpoint r0062 from the setpoint channel,
the actual value r0063 either directly from the speed actual value encoder for VC or through
the motor model for SLVC. The system error is amplified by the PI controller and, together
with the pre-control, forms the torque setpoint.
For increasing load torques, when the droop function is active, the speed setpoint is
proportionally reduced so that the load on an individual motor within a group (where two or
several motors are mechanically coupled) is reduced when excessively high torques occur.