Response of the new version: The magnetising current is automatically calculated at the end of the motor parameter identification with the values being extrapolated to the operating temperature of the motor.
What happens?
The magnetising current of the asynchronous motor (ASM) is calculated based on the motor nameplate data and the identified equivalent circuit diagram data.
In practical operation, the 'Motor parameter identification' commissioning function is usually not carried out when the motor is warm. The motor nameplate data are, however, rated values and therefore refer to the motor operating temperature at the rated point.
Mixing "cold" and "warm" data when calculating the magnetising current will lead to the corresponding deviations.
When does this behaviour occur?
The problem occurs if the 'Motor parameter identification' is not carried out with a warm motor.
Which products are affected? - i700 servo inverter
Short-term measures:
Select the motor magnetising current (0x2C02:3) manually. The magnetising current can be identified as follows: - Use V/f characteristic control and operate the motor at an idling speed of approx. 80% of the rated speed and
- measure the motor current.
Evaluation/recommendations: In practical operation, the described problem will only show effect if:
asynchronous motors from different manufacturers are used,
the motor parameters of these motors are not available in the motor data catalogue and can therefore not be loaded,
and the motor parameters have to be identified via the commissioning function.
