Stray load losses are modeled similar to standards EN 60034-2 and IEEE 112, i.e., they are dependent on square of current, but without scaling them to zero at no-load current.
For an estimation of dependency on varying angular velocity
see:
W. Lang, Über die Bemessung verlustarmer Asynchronmotoren mit
Käfigläufer für Pulsumrichterspeisung, Doctoral Thesis, Technical
University of Vienna, 1984.
The stray load losses are modeled such way that they do not cause a voltage drop in the electric circuit. Instead, the dissipated losses are considered through an equivalent braking torque at the shaft.
The stray load loss torque is
tau = PRef/wRef * (i/IRef)^2 * (w/wRef)^power_w
where i
is the current of the machine and
w
is the actual angular velocity. The dependency of
the stray load torque on the angular velocity is modeled by the
exponent power_w
.
If it is desired to neglect stray load losses, set
strayLoadParameters.PRef = 0
(this is the
default).