Magnetic characteristics of saturable pulse transformer in magnetic pulse compression system

Abstract

Saturable pulse transformer (SPT) is finding increased use in Magnetic Pulse Compressor (MPC). SPTs are fabricated from ferromagnetic amorphous metal alloy ribbons. And the magnetic characteristics of these amorphous metals are discussed in relation to optimizing the performance of SPTs in such applications. To evaluate the magnetic performance of the magnetic core, a `1-cosine' waveforms test stand is designed and built. The test stand is able to operate at modest repetition rates. The magnetization rates achieved in the experiments extend from 0.8 to 2.5 T/¿s, corresponding to saturation times from 1 to 4 ¿s. The current through the core is calculated by voltage across the resistive load, and the loop voltage is picked up with a single wire loop and integrated by software. B-H curves are derived from the measured voltage and current waveforms. Comparisons are presented for two Metal-glass cores which one is Mylar-insulated and the other not. Of the Mylar insulated core the trend is clear that increasing the packing factor, corresponding to increasing the winding tension, and more material in the core, tended to reduce the usable volt-second area and the eddy current loss together. Formulas are given for selecting core dimensions for IGBT switch protection. Finally, more practical energy transfer in SPT and the effects of leakage current are presented by applying custom characteristics to a two-stage MPC in Pspice simulation.