Motor torque characteristic
The required current setpoint is determined in relation to the torque setpoint, based on the motor torque characteristic. This current setpoint is then fed to the current controller. The actual torque for the actual current is also based on the motor torque characteristic. When the torque controller is used with Beckhoff motors, the data required for the motor torque characteristic are included in the electronic type plate or the motor data files (.xeds).
If the precise motor characteristics (saturation effects) are not available via the motor torque characteristic (blue curve), an approximation based on the diagram shown below is used.
This approximated function (based on linear interpolation) is formed from the IDNs:
- P-0-0070, P-0-0073, S-0-0111 and S-0-0109 for rotary motors and
- P-0-0126, P-0-0128, S-0-0111 and S-0-0109 for linear motors
(see red characteristic curve).
If only the standstill torque (P-0-0070) with corresponding standstill current (S-0-0111) is available, a conversion is performed via KT0 (green characteristic curve).
