PLI: With very small motors (very low mass moment of inertia) an overcurrent error message can occur (corrected from V02.15.02)
Corrected from:
Servo inverter i700, V1: no remedy planned for V1
Servo inverter i700, V2: from V02.15.02.12693
Response of the new version:
The sporadic response of the overcurrent monitoring no longer occurs. The influence of the EMF feedforward is now deactivated during PLI device-internal operation. There are no negative effects during a firmware update if the short-term remedy described below is already implemented.
What happens?
Sporadically, the current monitor responds and the error message Overcurrent is output.
When does the behaviour occur?
Execution of the pollage identification (PLI-360° or PLI min. movement) and
Use of a particularly small synchronous motor with very low mass moment of inertia.
Which products are affected?
Servo inverter i700, V1
Servo inverter i700, V2
Short-term measures/ Evaluation/ Recommendations:
The reason for the current peak occurring right at the beginning of the PLI is the influence of the EMF pre-control in the motor control, in conjunction with the dynamic compensation movement of the small motor.
The EMF feedforward can be deactivated for the duration of the PLI as follows:
Set the 'EMF time constant' under parameter 0x2C03:1 (0x3403:1) to zero.
Set the original value under parameter 0x2C03:1 (0x3403:1) again after completion of the PLI.
