Frequently asked questions
How is the Otr (motor torque) parameter calculated on the ATV61 and ATV71 drives?
28 September 2021Issue:
Otr motor torque parameter calculated on the ATV61 and ATV71 drives.
Altivar ATV61 and ATV71
Needs to know how the motor torque Otr parameter is calculated
The torque of motor (OTR) is not measured by the drive. It is calculated from the measurement of motor current.
OTR = (Iq / Iqn) * (PhirdRef / Phirn) in %
With: Iq : Current torque provide by the command to drive motor
PhirdRef : Flux provide by the command to drive motor
Iqn : Nominal Current torque compute with the motor name plate
Phirn : Nominal flux of the motor
The maximum accuracy of motor torque is 5% (in closed loop). It can be up to 15% in open loop.
Concerning the range, OTR is expressed in % of nominal motor torque.
100% = Nominal motor torque.
OTR value is signed with minimum value -300% and maximum value 300%