Stalling protection
The stalling monitoring for the sensorless control of synchronous motors (SL-PSM) switches off the drive if the motor is about to "stall". A possible cause may be an overload of the motor.
Preconditions
The stalling monitoring only works in the controlled area and if the motor is not operated in the field weakening range.
Details
In order to detect the motor stalling, the cosine phi is used.
Example:
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For the cosine phi, the value "0.9" is set in 0x2C01:008 (P320.08) according to the data given on the motor nameplate.
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The limit value for stalling monitoring is set in 0x2C11:006 to "80 %".
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Stalling monitoring is triggered if the current cosine phi is lower than 0.72 (80 % of 0.9).
If stalling monitoring is triggered, the "Trouble" error response takes place. If the operating mode "MS: Velocity mode [-2]" is set in 0x6060 (P301.00), the motor automatically restarts if the trouble does not exist any more.