Finite element modeling of eddy current and force distribution for induction dampers

For the numerical investigation and design improvement of induction dampers, the eddy current and force distribution on the plunger of a single stage induction damper is analyzed using the three dimensional (3D) finite element method. The flux and eddy current distributions are obtained using the 3D eddy current analysis of the magnetic field and the Lorentz force generated in the plunger is calculated using the nodal force method. The results show that the Lorentz force on the plunger can be increased with iron core inside or iron yoke outside the coil, whereas the force is larger with the iron core compared to the yoke. Considering the skin effect of eddy current and increasing the flux interlinking the plunger, an improved induction damper model had been proposed.