Simple Calculation Method of DC Superimposition Characteris-tics for Gapped Inductor

Abstract:
Inductors used in chopper circuits and choke-input-type rectifier circuits have the problem that the inductance and loss values change in complex manner when a DC current component flows through them. This is because that the permeability of the inductor core material varies nonlinearly in response to the DC superimposition. For this reason, inductors must be designed appropriately, taking into consideration the DC superimposition characteristics of the inductance and iron loss values, as well as the air gap structure of the core material to prevent the magnetic saturation. In this paper, we propose a simple calculation method of the DC superimposition characteristics of the inductance and iron loss for the gapped inductor using the relationship between the DC magnetization curve and the B-H minor loop under the DC superimposition. The calculated results are confirmed its validity in the experiments.