Ferromagnetic hysteresis is important in many areas of electrical engineering design both as a useful and unwanted phenonomen. Examples include the minimisation of electrical losses in transformers, residual forces in actuators and hysteresis motors.
In the Opera-3d suite a practical engineering approach to modelling has been developed. 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 method is practical because it: • Makes only realistic demands on the user for material data • Provides a good approximation to the true physical behavior • Does not require large computational resources |  |
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 turning points.
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.