Siemens CU240S DP-F - Slip Compensation

Functions
8.24 Open-loop and closed-loop control
Control Units CU240S
Operating Instructions, 11/2006, A5E00766042B AA
8-165
Parameter Voltage boost Explanation
P1312 Voltage boost when
starting
The voltage boost is only effective when accelerating for the first time
(standstill)
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8.24.1.2 Slip compensation
Data
Parameter range: P1335
Warnings: -
Faults: -
Function chart number: FP6100
Description
In the V/f characteristic operating mode the motor frequency is always lower than the inverter
output frequency by the slip frequency f
s
. If the load (the load is increased from M1 to M2) is
increased with a constant output frequency, then the slip increases and the motor frequency
decreases (from f1 to f2). This behavior, typical for an induction motor, can be compensated
using slip compensation P1335. This therefore eliminates the speed reduction, caused by
the load, by boosting (increasing) the inverter output frequency (see figure below).