Dynamic model of an electromagnetic massive core brake actuator

A dynamic model has been developed for the simulation of transient behavior of the disk axial motion in a cylindrical massive iron core electromagnetic brake comprising dc excitation. The model is based on magnetic and electric equivalent circuits of iron core. The flux and the eddy current distribution in the massive iron core are described by coaxial shells. Within each shell, uniform current and flux distribution are assumed. Lumped parameters are used for the evaluation of reluctances. The transient problem is solved in two steps. First, two sets of steady-state solutions are solved by iteration-one following a rising, and the other a falling magnetization curve. In the second step, the equivalent coil, the magnetic and eddy current circuits, and the mechanical system are expressed in a state variable form and analyzed with a general-purpose simulation program. Simulated transients during magnetization and demagnetization are compared to experimental results. The model is suitable for educational and commercial purposes.