How is the MDM (motor driven machine) torque calculated when no machine is explicitly modelled for an asynchronous machine?
In general two different options exist:
1. An explicit description of the motor driven machine (MDM) is defined.
In this case a composite model connects the asynchronous machine with the load characteristic. This is the most flexible option.
2. No explicit description of the MDM is defined.
By default the asynchronous motor is internally connected to a motor driven machine (e.g. a pump). The speed torque characteristic is
torque(speed) = (mdmlp*speed)^mdmex
so a decreasing frequency leads to a decreasing torque. The two parameters can be set on the RMS simulation page of the asynchronous machine dialogue box.
For more information refer to the MDM Technical Reference.