Steady-state and transient operational behaviour of a plunger core reactor with parallel windings

The steady-state and transient behaviour of a plunger core reactor with four parallel connected winding paths is calculated from voltage driven finite element analyses. The 3D finite element model utilizes a direct circuit coupling to take into account the applied voltage and the parallel windings paths. Consequently, the unknown coil currents are obtained with the full influence of the axial position of the plunger core. In case of steady-state conditions, the coil currents obtained from the numerical analyses are compared with those obtained from measurements. Moreover, the Lorentz forces acting on the coil windings and the Maxwell forces acting on the plunger core are calculated in dependence of the plunger core air-gap.