Loss Characteristics of a Magnetic Core for Pulsed Power Applications

A low-inductance circuit has been fabricated in order to investigate loss characteristics of the magnetic cores under fast pulse magnetization. The B-H curves have been derived from the measured voltage and current waveforms, and the losses of the magnetic cores have been derived using a novel method to determine time to saturation. The derived B-H curves show the following characteristics: a high ratio of unsaturated to saturated permeability (mu_un/mu_sat), a maximum flux swing of about 2.5 T, a high ratio of remanent flux density to saturation magnetic flux density (B_r/B_s), and a low core loss. Furthermore, the core loss increases as the charging energy increases for a fixed capacitance, which means that the core loss is inversely proportional to the time to saturation, whereas the percentile core loss decreases as the charging energy increases. The hysteresis loss is proportional to frequency, and the eddy current loss can be neglected for the used core. The dissipated energy during core saturation is consistently 3.0% of the charging energy for each frequency, which indicates that the core is saturated and behaves as an air core.