Electromagnetic retarders follow the basic principles of
electromagnetic induction. An eddy current machine has an
iron core where eddy currents are induced by a field-wound
stator through an excitation current. A retarding torque is subsequently
generated according to Lorentz equation [5]. The
retarding energy is dissipated as heat through the eddy current
flow in the core. Simeu and Georges [1] proposed an eddy
current brake model as a function of excitation current and
the rotor speed. However, the assumption that the retarding
force or torque is a linear function of the rotor speed results
in a less accurate eddy current machine model, according to
the observations made at Visteon. As explained in [6] and [7],
the departure from the linear behavior for the braking torque