MATLAB: Dc machine as dc motor

Question

I want to use the dc machine block in the Sim Power Systems as a dc motor but the inputs are mechanical torque and speed. Where should i take the mechanical output from? Could you please elaborately explain how to operate the dc machine in its two modes

Answer 1

From the DC Machine documentation:

Select Torque TL to specify a torque input, in N.m, and change labeling of the block's input to TL. The machine speed is determined by the machine Inertia J and by the difference between the applied mechanical load torque TL and the internal electromagnetic torque Te. The sign convention for the mechanical torque is the following: when the speed is positive, a positive torque signal indicates motor mode and a negative signal indicates generator mode.

Select Speed w to specify a speed input, in rad/s, and change labeling of the block's input to w. The machine speed is imposed and the mechanical part of the model (Inertia J) is ignored. Using the speed as the mechanical input allows modeling a mechanical coupling between two machines and interfacing with SimMechanics and SimDriveline models.

Did you look at the demo power_dcmotor.mdl?

HTH,

Arnaud