Ferromagnetic hysteresis is important in many areas of
electrical engineering design both as a useful and also as an
unwanted phenomenon. The ability to model hysteresis can be used
for example to minimize hysteresis losses in transformers and
In the Opera-3d suite a semi-empirical method for modelling
hysteresis has been developed alongside industrial partners. The
magnetic behaviour is considered as a trajectory B(H). The
trajectory is based on a measured major symmetric loop that is
supplied by the user. This data may be easily obtained from
measurements or published data-sheets, and imported into Opera as a
magnetic characteristic table.
The Opera hysteresis model includes the issues of nested minor
loops and 'wiping out' of minor loops, which occurs when the
trajectory goes through an earlier turning point. Moreover, the
model recognises oscillating fields and minimises the storage of
Transition to saturation is treated automatically, allowing the
simulation to overcome any limitations in the user's data.
Hysteretic material models are available in all Opera-3d
transient electromagnetic simulations - dynamics, rotating and
linear motion and demagnetisation.