Eliminated from:
- i700 servo inverter V01.03.08.9047
Response of the new version:
When a setpoint speed of 0.0 rpm is selected, the motor shaft no longer rotates as described-above.
What happens? Despite selection of a setpoint speed of 0.0 rpm, the motor shaft rotates at low speed.
When does the problem occur?
The problem occurs if 'V/f characteristic control' is used (0x2C00 =6) and
slip compensation is active (0x2B09:1 > 0):
In the case of low output frequencies in the range of +/-1Hz, inaccuracies in the slip compensation calculations may lead to a rotation of the motor shaft although a setpoint speed of 0.0 rpm is selected.
Which products are affected?
- i700 servo inverter ≤ V01.02.04.8817
Short-term measures/recommendations:
Switch off the slip compensation (0x2B09:1 = 0) or inhibt the controller for a short time and enable it again, if permitted by the application.
Evaluation:
Basically, 'V/f characteristic control' as a controlled motor control mode without a higher-level control loop is not suited to ensure the drift-free standstill of the motor, if only the speed setpoint is selected with 0.0 rpm. In order to ensure the standstill of the motor, other measures, e.g. the installation of a mechanical holding brake, are required, if necessary.
