Slip Compensation - Siemens MICROMASTER 440 Parameter Manual

Parameter Description
3.29.1.1

Slip compensation

P1335[3] Slip compensation
CStat: CUT
P-Group: CONTROL
Dynamically adjusts output frequency of inverter so that motor speed is kept constant independent of motor
load.
In the V/f-control, the motor speed will always be less than the command speed due to the slip speed. For a
given speed command, the speed will drop as load is increased. The speed regulation of drive can be
improved by the technique known as slip compensation.
Increasing the load from M1 to M2 (see diagram) will decrease the motor speed from f1 to f2, due to the
slip. The inverter can compensate for this by increasing the output frequency slightly as the load increases.
The inverter measures the current and increases the output frequency to compensate for the expected slip.
Without slip compensation
M
M
2
M
1
Index:
P1335[0] : 1st. Drive data set (DDS)
P1335[1] : 2nd. Drive data set (DDS)
P1335[2] : 3rd. Drive data set (DDS)
Value:
P1335 = 0 % :
Slip compensation disabled.
P1335 = 50 % - 70 % :
Full slip compensation at cold motor (partial load).
P1335 = 100 % :
Full slip compensation at warm motor (full load).
Range of slip compensation :
%
P1335
Notice:
The applied value of the slip compensation (scaled by P1335) is limited by following equation:
f
Slip_act
r0065
f
Setpoint
set
channel
r1078
162
Datatype: Float
Active: Immediately
With slip compensation
M
M
2
M
1
f
∆f
f f
2 1
f
out
f
6 % 10 % 100 %
N
P 1335
f
Slip_comp_max
100
f
act
r0063
Min:
Unit: % Def:
QuickComm.: No Max:
f
∆f
f f f
out M2
2 1
f
out M1
f
out
f
N
6 % 10 %
P1335
f
Slip_comp_ max
r1337
f
out
MICROMASTER 440
Issue 01/06
Level
0.0
2
0.0
600.0
with
slip compensation
without
slip compensation
f
set
f
N
P1336
= ⋅
r0330
100
Parameter List
6SE6400-5BB00-0BP0