The study of transient electromagnetic fields in a multi-turn, voltage-excited laminated core reactor

A combined explicit and implicit finite-different scheme is used for analyzing transient electromagnetic fields in a multiturn, voltage-excited reactor with a laminated core of nonlinear magnetic property. In the analysis, the reactor is divided into iron, air and winding regions. By applying a step function and a time-variant sinusoidal voltage source, the time-dependent magnetic vector potential function is obtained with the aid of B-μ table. The transient responses of the current and inductance are given. The computed results are compared with those of an ideal R-L circuit, and an excellent agreement between the light-load result and the ideal value is found. The nonlinear effects on currents, flux distributions, inductances, and magnetic vector potentials due to the saturated iron core can be found in a heavy load condition