The motor jerks when being started out of a controller inhibit and it rotates briefly in the wrong direction.
When does the problem occur?
If the controller is enabled after a brief controller inhibit in the vector control mode without feedback. In the internal motor model the flow is set to 0 in case of a controller inhibit. The decay time of the flow is not considered. This behaviour occurs when using drives < 1.5 kW with a relatively low inertia.
Possible diagnostics?
None.
Short-term measures/recommendations?
Delay the controller enable for a short period of time so that the controller can only be re-enabled after the controller enable signal if the motor is demagnetised. Please observe the connection proposal below.
Evaluation:
The motor rotates unintentionally backwards by up to 45 ° which corresponds to 1/8 motor revolution. The torque which can lead to the motor rotation is exclusively generated because of the residual flow inside the machine and is therefore relatively low.
