Danfoss iC7 Series Application Manual page 221

Application Guide | iC7 Series Industry
While the drive is in torque control, motor speed is not controlled. Motor speed can reach speed limits, when the load application or
upper system such as PLC system does not operate within the speed limits. If a speed limit is reached, the drive prevents itself from
exceeding the limit depending on the selection in the parameter Speed Limit Mode Torque Ctrl. Detailed descriptions of the selections
available in parameter Speed Limit Mode Torque Ctrl.
Pos./neg. frequency limit
By default, the selection for the parameter Speed Limit Mode Torque Ctrl. is Pos./Neg. Frequency Limit. While the drive is in torque
control, the speed is not limited by the speed reference, only by the positive frequency limit and by the negative frequency limit.
Speed
[RPM]
Positive Frequency Limit
Drive in Torque Control
Drive in Torque Control
Negative Frequency Limit
Figure 72: Pos./Neg. Frequency Limit
Limited by ramp
While the drive is in torque control, the speed is limited by the reference (after ramp). The speed increases with the set ramp time
until actual torque is equal to the torque reference. If the speed is below the reference when load is removed from the shaft the speed
increases without ramp.
Speed
[RPM]
Positive Frequency Limit
Actual Speed Reference
Ramp
Actual Speed Reference
Negative Frequency Limit
Figure 73: Limited by Ramp
Neg. limit to ramp
The torque controller operates in the range between the frequency limit for the negative direction and the speed limit given by the
ramp.
© 2024.05
Speed Controller Active
Speed Controller Active
Speed Controller Active
Drive in Torque Control
Drive in Torque Control
Speed Controller Active
Time
Time
AB480436531518en-000601 / 136R0283 |
Parameter Descriptions
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