Advanced commissioning
6.15 Motor control
Converter with the control units CU240D-2
202
Operating Instructions, 04/2018, FW V4.9 SP10, A5E34262100B AF
Mastering critical applications
The drive control can become unstable for drives with a high load moment of inertia and
gearbox backlash or a coupling between the motor and load that can possibly oscillate. In
this case, we recommend the following settings:
●
Increase p1452 (smoothing the speed actual value).
●
Increase p1472 (integral time T
I
): T
I
≥ 4 · p1452
●
If, after these measures, the speed controller does not operate with an adequate dynamic
performance, then increase p1470 (gain K
P
) step-by-step.
The most important parameters
Table 6- 37 Encoderless speed control
Parameter Description
p0342
Moment of inertia ratio, total to motor (factory setting: 1.0)
p1496
Acceleration precontrol scaling (factory setting: 0 %)
For the rotating measurement of the motor data identification the inverter sets the
parameters to 100 %.
p1452
Speed controller speed actual value smoothing time (without encoder) (factory setting:
10 ms)
p1470
Speed controller operation without encoder P gain (factory setting: 0.3)
p1472
Speed controller operation without encoder integral action time (factory setting: 20 ms)
6.15.2.4
Advanced settings
K
p
- and T
n
adaptation
The K
p
- and T
n
adaptation suppresses possible speed controller oscillations. During basic
commissioning, the inverter optimizes the speed controller using the "rotating measurement"
function. If you have performed the rotating measurement, then the K
p
- and T
n
adaptation has
been set.
You can find additional information in the List Manual, function block diagram 6050.
