Direct Modeling of Inductor Saturation Behavior in a SPICE-Like Transient Analysis

Abstract

In this paper, we demonstrate how the saturation behavior of an inductor can be directly inserted as a software function into the mathematical description of a circuit and included in a SPICE-like numerical simulation. Within the numerical computation of the circuit, the inductance value changes in dependence on the actual inductor current, following the real-life behavior of the choke. The procedure shown provides more exact and realistic simulation results then assuming the inductance to be a constant value, which is the common way in SPICE programs. Based on an example choke, we show how any saturation curve, derived from measurement data or core manufacturer's information, can be inserted into a computational model of the inductance. This is a significant advantage over the possibilities to model inductor saturation, which different SPICE programs are offering, what is also shown in the paper. On the application of a boost converter, the impact of the consideration of the saturation on the simulation result is presented and compared with a simulation with a constant inductor.