Circuit Breakers

Outstanding Features for the coupling of electromagnetic, elasticity, motion and thermal allow realistic simulations of circuit breakers and switchgears.

The animation demonstrates the FEM simulation of a low-voltage circuit breaker. A voltage is applied to a coil (below), whereupon the plunger is pulled into the coil. The four contact bridges (above) are connected to the plunger and then press on their contact partners, whereupon the AC current flows through the lines. The Lorenz forces lead to small mechanical vibrations with contact friction and the heating is also calculated with line losses and eddy currents. Later the coil is switched off and the plunger moves back up and opens the contacts again. Colors in the film show the electrical current density. This simulation technology combines elasticity with electromagnetics and thermals. The special feature here are the multiphysical contacts that couple all three disciplines (elasticity, EM, thermal).